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Okukora amashanyarazi g‘okukora adipic acid (ekirikubanza omu nylon 66) kuruga omu mafuta ga CA (omutaano gwa cyclohexanone na cyclohexanol) n‘enkora egumire erikubaasa kuza omu mwanya gw‘emiringo y‘obuhangwa erikwetenga embeera zigumire. Kwonka, oburemeezi bw’amashanyarazi obukye n’okuhakanisa kw’okutunguuka kw’omwiika nibikyendeeza munonga aha kukozesa kwayo omu makorero. Omu murimo ogu, nituhindura nickel double hydroxide na vanadium kwongyera aha nkora y‘obwire obu n‘okurinda obushoboorozi bwa faradaic bw‘ahaiguru (>80%) aha nkora mpango y‘obushoboorozi (1.5–1.9 V vs. amashanyarazi g‘okugaruka enyima). Okucondooza okw’okugyezesa n’okw’ebiteekateeko kukashohoza emirimo ebiri mikuru ey’okuhindura V, harimu okugaruka kwombeka ekirikureetaho okurahuka n’okutunguura okunywanisa kwa cyclohexanone. Nk‘obuhame bw‘ebiteekateeko, tukakora oruteerane rw‘eby‘okurya-eby‘amashanyarazi ebyabaire nibireetaho adipic acid n‘obushoboorozi bwa faradaic bw‘ahaiguru (82%) n‘okukora (1536 μmol cm-2 h-1) aha nkora y‘amashanyarazi erikukwatagana n‘amakorero (300 mA cm-2), obwo turikuhikiiriza okuhama >50 h. Omurimo ogu nigworeka ekikwato ekirungi ekirikureetaho amashanyarazi g’okukora adipic acid n’okukora munonga n’obushoboorozi bw’amakorero.
Adipic acid (AA) n’emwe aha asidi ezirikukirayo obukuru kandi neekoresibwa munonga omu kuhanga nayiloni 66 n’ebindi bihingwa ebirimu ebiriisa nari ebiriisa1. Omu by’amakorero, AA neekorwa omu kuhindura omubazi gw’okutabura cyclohexanol na cyclohexanone (nikwo kugira ngu, amajuta ga AA) orikukoresa 50–60 vol% nitric acid nk’ekintu ekirikuhindura omubazi. Enkora egi eine okwerarikirira kw’eby’obuhangwa okurikukwata aha kusheeshasheesha kw’ekiriisa kya nitric acid n’ekiriisa kya nitrogen oxides (N2O na NOx) nk’eby’obuhangwa2,3. N’obu H2O2 eraabe neebaasa kukoresibwa nk’omuringo ogundi ogw’okureetaho okukyendeeza aha nkora ya green oxidizing agent, esente zaayo nyingi n’embeera z’okukora ezigumire nizireetera kigumire kukoresibwa omu bikorwa, kandi omuringo ogurikukirayo obukye kandi ogurikugumizamu nigwetengyesa4,5,6.
Omu myaka ikumi ehweire, emiringo y‘okukora emibazi y‘amashanyarazi n‘amajuta etungire okweyongyera kw‘okuta omutima aha banyasayansi ahabw‘oburungi bwayo obw‘okukoresa amaani agarikugarukaho n‘okukora omu mbeera ezitari nkuru (nk‘eky‘okureeberaho, obutagatsi bw‘omu kishengye n‘obutagatsi bw‘omu mwanya)7,8,9,10. Omu nshonga egi, okukora okuhindura amajuta ga KA kuba AA omu muringo gw’amashanyarazi ni kikuru munonga kutunga oburungi obu aharuguru hamwe n’okumaraho okukoresa nitric acid na nitrous oxide emissions ezirikushangwa omu kuhanga eby’obutoosha (ekishushani 1a). Omurimo gw‘okubanza gukakorwa Petrosyan na bagyenzi be, abaagambire aha nkora y‘okuhindura ebiriisa by‘omubiri (COR; ebiriisa by‘omubiri nari ebiriisa by‘omubiri (cyclohexanone nari cyclohexanol) bibaire nibikira kwega nk‘ebirikujwekyera amajuta ga KA) aha nickel oxyhydroxide (NiOOH%) omuringo gw‘okwotsya (NiOOH%) oguri ahansi cmraA2d) . bakatunga11,12. Kuruga obwo, entunguuka mpango ekozirwe omu kuhanga ebikwato ebirikukora aha nickel kutunguura emirimo ya COR. Nk’eky’okureeberaho, ekirungo ky’omuringa (Cu-Ni(OH)2) kikakorwa kutunguura okucwanyagura kwa Cα–Cβ omu cyclohexanol13. Tuherize kuhandiika aha nkora ya Ni(OH)2 ehindwirwemu n’ekiriisa kya sodium dodecyl sulfonate (SDS) kuhangaho embeera y’amaizi erikugaita cyclohexanone14.
a Oburemeezi bw‘okukora AA kurabira omu kuhindura amajuta ga KA omu nkora y‘amashanyarazi. b Okugyeragyeranisa COR y’amashanyarazi g’ebyoma ebyagambirweho enyima ebirikwegamira ahari Ni n’ebyoma byaitu omu nkora y’amashanyarazi ashatu n’enkora ya battery ezirikugyendera11,13,14,16,26. Amakuru agarikukwata aha nkora y‘okugarukamu n‘okukora kw‘okugarukamu nigaheebwa omu bipande by‘okwongyeraho 1 na 2. c Okukora kwa catalytic kw‘ebikwato byaitu bya NiV-LDH-NS eby‘okugarukamu bya COR omu H-cell reactor na MEA, ebirikukora aha nkora mpango y‘obushoboorozi.
N‘obu emiringo egi aharuguru eraabe yaatunguura emirimo ya COR, ebikwato ebishobooroirwe ebirikwegamira ahari Ni bikooreka obushoboorozi bw‘ahaiguru bwa AA Faraday (FE) (>80%) aha bushoborozi bukye bwonka, okukira munonga ahansi ya 1.6 V kugyeragyeranisa n‘ekikwato ky‘okugaruka enyima (RHE, omubugufu VRHE). Nahabwekyo, oburemeezi bw‘ekicweka ky‘amashanyarazi oburikugambwaho (nikwo kugira ngu, oburemeezi bw‘amashanyarazi bwona oburikukanyisibwa na FE) bwa AA butoosha buri ahansi ya 60 mA cm−2 (ekishushani 1b n‘ekipande ky‘okwongyeraho 1). Oburemeezi bw‘amashanyarazi obukye buri ahansi munonga y‘ebyetengo by‘amakorero (>200 mA cm−2)15, ekirikuremesa munonga tekinologiya y‘amashanyarazi ahabw‘okukora AA ey‘amaani (ekishushani 1a; ahaiguru). Okwongyera aha nkora y‘amashanyarazi, obushoboorozi oburungi munonga (ahabw‘enkora y‘amashanyarazi ashatu) nari amaani g‘obutafaari maingi (ahabw‘enkora y‘amashanyarazi abiri) nigabaasa kukoresibwa, eri enkora eyorobi ahabw‘entunguuka nyingi z‘amashanyarazi, namunonga enkora y‘okuhinduka kw‘omwiika (OER). Kwonka, ahari COR aha bushoboorozi bwa anodic bw‘ahaiguru, OER neebaasa kuba omuhagizi mukuru omu kukyendeeza FE ya AA, obwo erikukyendeeza aha nkora y‘amaani (ekishushani 1a; ahansi). Nk‘eky‘okureeberaho, twashwijuma entunguuka eyabandize (ekishushani 1b n‘ekipande ky‘okwongyeraho 1), tukahwamu amaani kushanga ngu FE ya AA aha SDS-modified Ni(OH)2 ekakyendeera kuruga ahari 93% kuhika ahari 76% n‘okwongyera aha bushoborozi oburikukoresibwa kuruga ahari 1.5 VRHE kuhika ahari 1,7 theVRAAHE ahari 1.7. CuxNi1-x(OH)2/CF ekakyendeera kuruga ahari 93% kuhika ahari 69% n’okwongyera aha bushoborozi kuruga ahari 1.52 VRHE kuhika ahari 1.62 VRHE16. Nahabwekyo, oburemeezi bw‘ekicweka ky‘obwire obu bwa AA oburikugambwaho tiburikweyongyera omu kipimo aha bushoborozi bw‘ahaiguru, ekirikukyendeeza munonga aha kutunguuka kw‘okukora kwa AA, tutarikugamba aha kukozesa amaani maingi ahabw‘okugira ngu FE ya AA eri ahansi. Oyihireho ebikwato ebirikwegamira ahari nickel, ebikwato ebirikwegamira ahari cobalt nabyo byorekire emirimo y’ekikwato omu COR17,18,19. Kwonka, oburungi bwazo nibukyendeera aha bushoborozi bw’ahaiguru, kandi waagyeragyeranisa n’ebintu ebirikureetaho okutunguuka ebirikwegamira ahari Ni, biine obugarukiro bw’obushoboorozi bwingi omu kukozesa amakorero, nk’okuhinduka kw’emihendo kwingi n’ebintu bikye ebiri omu katare. Nahabwekyo, nikirungi kukora ebikwato ebirikwegamira ahari Ni ebiine oburemeezi bw’amaani bw’amashanyarazi n’eby’okurya bya FE omu COR kubaasa kukikora kubaasa kutunga ebirikurugamu bingi ebya AA.
Omu murimo ogu, nituha ripooti ya vanadium(V)-ehindwirwemu nickel erimu ebiriisa bibiri (NiV-LDH-NS) nk’ebikwato by’amashanyarazi ebirikukora gye omu kuhanga AA kurabira omu COR, ebirikukora aha rubaju rw’obushoboorozi bwingi n’ebicweka by’omubiri ebiine OER erikuzibirwa munonga, ebirikuhikiiriza FE y’ahaiguru n’obutafaari bw’amashanyarazi oburiho hati a Ekishushani HME-1; b). Nitubanza kworeka ngu obushoboorozi bw’okuhindura ebiriisa bya asetiini aha nkora y’omutaano eya Ni(OH)2 nanosheet (Ni(OH)2-NS) nibukyendeera, nk’oku kirikuteekateekwaho, aha bushoborozi bw’ahaiguru, kuruga ahari 80% ahari 1.5 VRHE kuhika ahari 42% ahari 1.9 VRHE. Omu kugyeragyeranisa, bwanyima y‘okuhindura Ni(OH)2 na V, NiV-LDH-NS ekooreka oburemeezi bw‘amaani obw‘obwire obu aha bushoboorozi obuhairwe kandi, ekikuru munonga, ekaguma eine FE y‘ahaiguru aha bushoboorozi bwingi. Nk‘eky‘okureeberaho, ahari 1.9 VRHE, kikakworeka oburemeezi bw‘obwire obu bwa 170 mA cm−2 na FE bwa 83%, ekirikukirayo oburungi omu kureetaho COR omu nkora y‘eby‘amashanyarazi bishatu (Fig. 1c n‘Ekipande ky‘okwongyeraho 1). Ebihandiiko by‘okugyezesa n‘eby‘okuteekateeka nibyoreka ngu okuhindura kwa V nikutunguura okukyendeeza kw‘okutambura kuruga ahari Ni(OH)2 kuhika aha Ni oxyhydroxides z‘omuhendo gw‘ahaiguru (Ni3+xOOH1-x), ezirikukora nk‘omuringo gw‘okukora ahabwa COR. Ekindi, okuhindura kwa V kukatunguura okushohoza kwa cyclohexanone aha rubaju rw’ekirungo, ekyakozire omurimo muhango omu kuzibira OER aha bushoborozi bw’ahaiguru obw’anodic. Okworeka obushoboorozi bwa NiV-LDH-NS omu mbeera y‘amazima, tukakora ekikwato ky‘okusheeshasheesha ekya MEA kandi twayoreka FE ya AA (82%) aha nkora y‘okusheeshasheesha ey‘amakorero (300 mA cm−2), eri ahaiguru munonga kukira ebyarugamu byaitu eby‘enyima omu nkora y‘okusheeshasheesha ya membrane na Supplement Table1 (Fig2). Ekirikurugamu ekirikuhikaana na AA (1536 μmol cm−2 h−1) kikaba kiri n’ahaiguru munonga kukira ekyatungirwe barikukoresa omuringo gw’okuhindura ebiriisa (<30 mmol gekirikureetaho ebiriisa−1 h−1)4. Ekindi, ekirikureetaho okuhinduka kikooreka okuhama kurungi baaba nibakoresa MEA, barikuguma baine FE >80% AA kumara eshaaha 60 ahari 200 mA cm−2 na FE >70% AA kumara eshaaha 58 ahari 300 mA cm−2. Eky‘aha muheru, okucondooza okubandize (FEA) kworekire ngu enkora y‘okukoresa amashanyarazi g‘okukora AA neebaasa kutwara sente nyingi.
Okurugirira aha bihandiiko ebyabandize, Ni(OH)2 n’ekintu ky’omutaano ekirikworeka emirimo mirungi ahari COR, n’ahabw’ekyo Ni(OH)2-NS13,14 ekakorwa omurundi gw’okubanza kurabira omu muringo gwa coprecipitation. Eby’okureeberaho byorekire omutindo gwa β-Ni(OH)2, ogwahamibwe okucondooza kwa X-ray (XRD; ekishushani 2a), kandi nanosheets ezikye munonga (obuhango: 2–3 nm, obuhango bw’aharubaju: 20–50 nm) zikakyeberwa ahabw’okucondooza kw’amaani g’okujanjaaza kw’eby’okureeberaho (HR1M Fig. 2a). (AFM) ebipimo (Ekishushani ky‘okwongyeraho 2). Okuteerana kwa nanosheets nakwo kukareebeka ahabw’obuhangwa bwazo obukye munonga.
a Emitwarize y‘okutambura kw‘ebishushani bya Ni(OH)2-NS na NiV-LDH-NS. FE, okuraba, na AA obuhango bw‘obwire obu aha b Ni(OH)2-NS na c NiV-LDH-NS aha bushoborozi obutarikushushana. Enshobi z‘emiti nizijwekyera okutaana kw‘omutindo gw‘ebipimo bishatu eby‘okwetongora barikukoresa ekirikureetaho kimwe. d Ekishushani kya HRTEM ekya NV-LDH-NS. Omubaro gw’okupima: 20 nm. Ekishushani kya HAADF-STEM kya NiV-LDH-NS na maapu y‘ebintu erikuhikaana nayo erikworeka oku Ni (kinyasi), V (kinyasi), na O (bururu) zirikugabwa. Omubaro gw’okupima: 100 nm. f Ni 2p3/2, g O 1 s, na h V 2p3/2 XPS ebirikukwata ahari Ni(OH)2-NS (ahaiguru) na NiV-LDH-NS (ahansi). i FE na j nizo AA zirikukora aha bikwatiraine n‘okureetaho ebiri aha nkora 7. Enshobi z‘emibaro nizijwekyera okutaana kw‘omutindo gw‘ebipimo bishatu eby‘okwetongora barikukoresa ekikwato kimwe kandi biri omu 10%. Ebihandiiko ebitahikire ebya a–c na f–j nibiheebwa omu fairo z’ebihandiiko ebitahikire.
Bwanyima tukashwijuma oku Ni(OH)2-NS erikukwata ahari COR. Twakozesa amashanyarazi g‘obushoboorozi obutarikuhinduka, tukatunga 80% FE ya AA aha bushoboorozi bukye (1.5 VRHE) hatariho OER (ekishushani 2b), ekirikworeka ngu COR neekira OER omu maani g‘amaani kukira OER aha bushoboorozi bukye bw‘anodic. Ekikuru ekirugiremu kikashangwa kiri glutaric acid (GA) erimu FE ya 3%. Okubaho kw‘ebicweka by‘omubiri ebikye (SA), malonic acid (MA), na oxalic acid (OA) nabyo bikakyeberwa HPLC (reeba ekishushani ky‘okwongyeraho 3 aha kugabwa kw‘ebintu). Tihariho formic acid eyashangirwe omu kintu eki, ekirikumanyisa ngu carbonate neebaasa kuhangwa nk’ekirungo kya C1. Okugyezaho enteekateeka egi, amashanyarazi kuruga omu kucondooza okuhikire okwa 0.4 M cyclohexanone gakahindurwa asidi kandi ebirugire omu gaasi bikahingura omu nkora ya Ca(OH)2. Ekirugiremu, omubazi gukahinduka omucuucu, ekirikuhamya okuhangwa kwa carbonate bwanyima y’okugihindura amashanyarazi. Kwonka ahabw‘amashanyarazi makye goona agarikuruga omu nkora y‘okukora amashanyarazi (ekishushani 2b, c), okuteerana kwa carbonate ni kukye kandi kigumire kubara. Okwongyera ahari ekyo, ebindi bihingwa bya C2-C5 nabyo nibibaasa kuhangwa, kwonka omuhendo gwabyo tigurikubaasa kukyeberwa. N‘obu omubaro gwona gw‘ebintu guraabe gugumire kugyeragyeranisa, 90% y‘omubaro gwona ogw‘eby‘amashanyarazi nigworeka ngu emiringo y‘amashanyarazi enyingi emanyirwe, ekirikuha omusingi gw‘okwetegyereza kwaitu okw‘eby‘obuhangwa. Ahabw‘okugira ngu amashanyarazi gakaba gari makye (20 mA cm−2), ebirugire omu AA bikaba biri 97 μmol cm−2 h−1 (ekishushani 2b), ekirikugyeragyeranisibwa na 19 mmol h−1 g−1 kurugiirira aha kuremeera kw‘oburemeezi bw‘ekintu ekirikureetaho (5 mg cm−2), ekiri ahansi y‘ekirungo ky‘okwotsya h~1 m−3 m−3. Obushoboorozi obukozesiibwe ku bwayeyongyeire kuruga ahari 1.5 kuhika ahari 1.9 VRHE, n‘obu oburemeezi bwona obw‘obwire obu bwayeyongyeire (kuruga ahari 20 kuhika ahari 114 mA cm−2), omu bwire nibwo bumwe hakabaho okukyendeera kw‘amaani omu AA FE, kuruga ahari 80% kuhika ahari 42%. Okukyendeera kwa FE aha bushoborozi burungi bwingi nikukira kubaho ahabw‘okuhakanisa OER. Namunonga ahari 1.7 VRHE, okurwanagana kwa OER nikureetaho okukyendeera kw‘amaani omu AA FE, obwo nikukyendeezaho kakye aha kukora kwa AA n‘okwongyera aha nkora y‘obwire bwona. Nahabwekyo, n‘obu oburemeezi bw‘ekicweka ky‘obwire obu bwa AA bwayeyongyeire kuruga ahari 16 kuhika ahari 48 mA cm−2 kandi n‘okukora kwa AA kweyongyeire (kuruga ahari 97 kuhika ahari 298 μmol cm−2 h−1), amaani maingi g‘okwongeraho gakakoresibwa (2.5 W h gAA−1 kukiraho kuruga ahari 1.5 kuhika ahari 1.9 carbon omu g.7. gAA−1 (ebihandiiko by‘okubara nibiheebwa omu kihandiiko ky‘okwongyeraho 1). OER eyaagambirweho enyima nk‘omuhiigi w‘okugarukamu kwa COR aha bushoboorozi bw‘ahaiguru bw‘anodic neekwatagana na ripoota ezabandize kandi neejwekyera oburemeezi bw‘omutaano obw‘okutunguura okukora kwa AA14,17.
Okubaasa kukora ekikwato kya COR ekirikukorera gye Ni(OH)2-NS, tukabanza twashwijuma omurundi ogurikukora. Twareeba enshonga z‘ahaiguru ahari 473 cm-1 na 553 cm-1 omu byarugamu byaitu eby‘okucondooza kwa in situ Raman (Ekishushani ky‘okwongyeraho 4), ebirikuhikaana n‘okugoma n‘okutambatambura kw‘enkoragana za Ni3+-O omu NiOOH, nk‘oku biri. Kihandiikirwe ngu NiOOH n’ekirugire omu kukyendeeza kwa Ni(OH)2 n’okuteerana kwa Ni(OH)O aha bushoboorozi bwa anodic, kandi n’omurundi gw’omugasho omu kuhindura kw’amashanyarazi20,21. Nahabwekyo, nituteekateeka ngu okutunguura omuringo gw’okugaruzaho omutindo gwa Ni(OH)2 kuza ahari NiOOH nikibaasa kwongyera aha mirimo y’okureetaho COR.
Twagyezaho kuhindura Ni(OH)2 n’ebyoma bitarikushushana ahabw’okuba kikareebeka ngu okuhindura heteroatom nikutunguura okugaruka kwombeka kw’omutindo omu byoma by’okuhindura oxides/hydroxides22,23,24. Sampuli zikaba zikozirwe omu kuteerana hamwe Ni n’ekyoma kya kabiri ekirikubanza. Omuri ebyo ebihindwirwemu eby‘ekyoma ebitarikushushana, eby‘okureeberaho ebihindwirwemu V (V:Ni atomic ratio 1:8) (ebirikwetwa NiV-LDH-NS) byorekire oburemeezi bw‘amaani bw‘obwire obu omu COR (Ekishushani ky‘okwongyeraho 5) kandi ekikuru munonga, AA FE y‘ahaiguru aha dirisa mpango y‘obushoboorozi. Okukira munonga, aha bushoborozi bukye (1.5 VRHE), oburemeezi bw‘obwire obu bwa NiV-LDH-NS bukaba buri ahaiguru emirundi 1.9 kukira obwa Ni(OH)2-NS (39 n‘ebicweka 20 mA cm−2), kandi AA FE ekaba neegyeragyeranisibwa aha bikwatiraine n‘okureetaho ebiriisa byombi (83% n‘ebicweka 80%). Ahabw‘okugira ngu hariho oburemeezi bw‘amaani bw‘obwire obu n‘okushushana kwa FE AA, okukora kwa NiV-LDH-NS nikukira okwa Ni(OH)2-NS emirundi 2.1 (204 vs. 97 μmol cm−2 h−1), kworeka okutunguuka kw‘okuhindura V aha buhango bw‘obwire obu aha bushoboorozi bukye (ekishushani 2).
Omu kweyongyera kw‘obushoboorozi oburikukoresibwa (nk‘eky‘okureeberaho, 1.9 VRHE), oburemeezi bw‘obwire obu aha NiV-LDH-NS buri ahaiguru emirundi 1.5 kukira ahari Ni(OH)2-NS (170 vs. 114 mA cm−2), kandi okweyongyera nikushushana n‘okw‘obushoboorozi oburi ahansi (emirundi 1.9 ahaiguru). Ekikuru, NiV-LDH-NS ekaguma eine AA FE y‘ahaiguru (83%) kandi OER ekaba neekyendeezibwa munonga (O2 FE 4%; Ekishushani 2c), ekakira Ni(OH)2-NS kandi ekaba egambirweho enyimaho n‘ebirikureetaho AA FE y‘ahansi munonga aha bushoboorozi bw‘ahaiguru bw‘anodic (Ekipande ky‘okwongyeraho 1). Ahabw‘okugira ngu FE y‘ahaiguru ya AA omu dirisa mpango y‘obushoboorozi (1.5–1.9 VRHE), omubaro gw‘okureetaho AA ogwa 867 μmol cm−2 h−1 (ogurikwingana na 174.3 mmol g−1 h−1) gukahikirizibwa obu 1.9 VRHE, kworeka okukora kurungi kw‘enkora y‘amashanyarazi n‘okukora kw‘amashanyarazi. normalized ahabw‘okuremesa kw‘omubaro gwona gw‘eby‘okureeberaho bya NiV-LDH-NS (Ekishushani ky‘okwongyeraho 6).
Kubaasa kwetegyereza oburemeezi bw‘amaani obw‘obwire obu n‘oburemeezi bw‘amaani bwa FE aha rubaju rw‘obushoboorozi bwingi bwanyima y‘okuhindura Ni(OH)2 na V, tukashoboorora aha nkora ya NiV-LDH-NS. Ebirugire omu kucondooza kwa XRD nibyoreka ngu okuhindura na V kukareetera okuhinduka kw’omutindo kuruga ahari β-Ni(OH)2 kuza ahari α-Ni(OH)2, kandi tihaine kika ky’ebicupuri ebiine akakwate na V ekyashangirwe (Fig. 2a). Ebirugire omu kucondooza kwa HRTEM nibyoreka ngu NiV-LDH-NS neehungura enkora y’ebipande bya Ni(OH)2-NS ebikye munonga kandi eine ebipimo by’aha rubaju ebirikushushana (Fig. 2d). Ebipimo bya AFM bikooreka omuze gw’okuteerana kw’amaani ogw’ebicweka bya nanosheets, ekyarugiremu obuhango oburikubaasa kupimwa oburikwingana 7 nm (Ekishushani ky’okwongyeraho 7), obuhango kukira obwa Ni(OH)2-NS (obuhango: 2–3 nm). Okushwijuma maapu y’okujanjaaza amaani (EDS) (ekishushani 2e) kukooreka ngu ebintu bya V na Ni bikaba bigabire gye omu nanosheets. Okushoborora aha nkora y’ebyoma bya V n’oku birikukora ahari Ni, tukakoresa eby’okureeberaho by’ebyoma bya X-ray (XPS) (Ekishushani 2f–h). Ni(OH)2-NS ekooreka obumanyiso bw’enshonga z’okuzibira Ni2+ (enshonga y’abakazi ahari 855.6 eV, enshonga ya satelayiti ahari 861.1 eV, ekishushani 2f)25. O 1 s XPS spectrum ya Ni(OH)2-NS neebaasa kubaganisibwamu enshonga ishatu, omu nshonga ezi enshonga eziri aha 529.9, 530.9 na 532.8 eV niziteebwaho omuyaga gw’omubiri (OL), ekibiina ky’amaizi (Ni-OH) n’omwiika ogurikukwatwa aha bizibu by’ahaiguruA), (O 2g)26,27,28,29. Bwanyima y‘okuhindura na V, enshonga ya V 2p3/2 ekareebeka, erikubaasa kuvunda omu nshonga ishatu ezirikushangwa ahari 517.1 eV (V5+), 516.6 eV (V4+) na 515.8 eV (V3+), nk‘oku biri, ekirikworeka ngu ebika bya V omu mbeera y‘omutindo gw‘ahaiguru okukira munonga biriho omu (ekishushani 1). 2h)25,30,31. Okwongyera ahari ekyo, enshonga ya Ni 2p ahari 855.4 eV omu NiV-LDH-NS ekahindurwa kubi (n’ebicweka nka 0.2 eV) kugyeragyeranisa n’eya Ni(OH)2-NS, ekirikworeka ngu obutafaari bw’omubiri bukaruga omu V kuza omu Ni. Embeera ya valensi y‘ahansi munonga eya Ni eyaareebekire bwanyima y‘okuhindura V ekaba neehikaana n‘ebyarugire omu kucondooza kwa Ni K-edge X-ray absorption near-edge spectroscopy (XANES) (reeba ekicweka kya “Okuhindura V nikutunguura okukyendeeza kw‘ekiriisa” ahaifo ahabw‘ebindi). NiV-LDH-NS bwanyima y‘okujanjaba COR kumara 1 h ekateebwaho nka NiV-LDH-POST kandi ekamanyirwa omu bwijwire barikukoresa okupima kw‘okujanjaaza kw‘eby‘amashanyarazi, okukora maapu ya EDS, okucondooza kwa X-ray, okupima kwa Raman, n‘okupima kwa XPS (Ebishushani by‘okwongyeraho 8 na 9). Ebirikureetaho okuhinduka bikaguma nk’ebirungo ebiine enkora ya nanosheet erikukye munonga (Ekishushani ky’okwongyeraho 8a–c). Obutafaari bw’eby’okureeberaho bukakyendeera kandi n’ebiri omu V bikakyendeera ahabw’okusheeshasheesha kwa V n’okugaruka kwombeka ekikwato ky’okureetaho (Supplementary Fig. 8d–f). Ebishushani bya XPS bikooreka okukyendeera kw‘amaani g‘enshonga ya V (Ekishushani ky‘okwongyeraho 9), ekyabaire nikireetwa okusheeshasheesha kwa V. Okwongyera ahari ekyo, okucondooza kwa O 1s spectrum (Ekishushani ky‘okwongyeraho 9d) n‘okupima kwa electron paramagnetic resonance (EPR) (Ekishushani ky‘okwongyeraho 10) bikooreka ngu omubaro gw‘ebicweka by‘omwika ebiri aha NiV-LDH-NS gukeyongyera bwanyima y‘eshaha 1 y‘amaani g‘okucondooza, ekirikubaasa kureetera okuhinduka kw‘amashanyarazi okubi omu kishushani kya Supp2p. 9 na 10 kumanya ebirikukiraho)26,27,32,33. Nahabwekyo, NiV-LDH-NS ekooreka empindahinduka nkye omu nkora bwanyima ya 1 h ya COR.
Okuhamya omurimo mukuru gwa V omu kutunguura COR, tukakora ebikwato bya NiV-LDH ebiine emibaro y’atomu ya V:Ni etari emwe n’emwe (1:32, 1:16, na 1:4, ebitebeekanisiibwe nka NiV-32, NiV-16, na NiV-4, buri kimwe) okwihaho 1:8 omu muringo nigwo gumwe gw’okuteerana. Ebirugire omu kucondooza kwa maapu ya EDS nibyoreka ngu omubaro gw’atomu V:Ni omu nkora y’okureetaho ebiriisa biri haihi n’ogw’ekikwato ky’okubanza (Ekishushani ky’okwongyeraho 11a–e). Okwongyera aha kuhindura kwa V, amaani g‘omuringo gwa V 2p nigayeyongyera, kandi amaani g‘okukwatira hamwe g‘ekicweka kya Ni 2p nigaguma nigahinduka gaza aha rubaju orubi (Ekishushani ky‘okwongyeraho 12). Omu bwire nibwo bumwe, omubaro gw‘abantu abaine OL gukeeyongyera mporampora. Ebirugire omu kukyebera kwa catalytic nibyoreka ngu OER neebaasa kukyeberwa gye n‘obu yaakuba yaaheza kuhindura V kakye (V:Ni atomic ratio ya 1:32), O2 FE neekyendeera kuruga ahari 27% kuhika ahari 11% ahari 1.8 VRHE bwanyima y‘okuhindura V (Ekishushani ky‘okwongyeraho 11f). Okweyongyera kw’omubaro gwa V:Ni kuruga ahari 1:32 kuhika ahari 1:8, omurimo gw’okureetaho ebiriisa gukeeyongyera. Kwonka, n‘okwongyera aha kuhindura kwa V (omubaro gwa V:Ni ogwa 1:4), oburemeezi bw‘obwire obu nibukyendeera, eki turikuteekateeka ngu nikireetwa okukyendeera kw‘oburemeezi bw‘ebicweka ebirikukora Ni (okukira munonga omurundi gw‘okukora NiOOH; Supplementary Fig. 11f). Ahabw‘okutunguura okuhindura kwa V n‘okurinda emyanya erikukoreramu Ni, ekirikureetaho okutunguuka ekiine omubaro gwa V:Ni ogwa 1:8 kikooreka okukora kwa FE na AA okurikukirayo omu kugyezibwa kw‘okushwijuma omubaro gwa V:Ni. Okubaasa kushoborora yaaba omubaro gwa V:Ni niguguma gutarikuhinduka bwanyima y’okukora amashanyarazi, ebicweka by’ebintu ebikozesiibwe bikamanyisibwa. Ebirugiremu nibyoreka ngu aha bikwatiraine n’ebiriisa ebiine emibaro ya V:Ni ey’okubanza kuruga ahari 1:16 kuhika ahari 1:4, omubaro gwa V:Ni gukeyongyera kuhika ahari 1:22 bwanyima y’okukora, ekirikubaasa kuba kyarugire omu kusheeshasheesha kwa V ahabw’okugaruka kwombeka ebikwato ebirikukora (Supplementary Fig. 13). Yetegyereze ngu AA FEs ezirikugyeragyeranisibwa zikakyeberwa obu omubaro gw‘okubanza ogwa V:Ni gwabaire guringana nari guri ahaiguru ya 1:16 (Ekishushani ky‘okwongyeraho 11f), ekirikubaasa kushoboororwa okugaruka kwombeka kw‘ekikwato ky‘okukyebera ekirikureetaho omubaro gwa V:Ni ogurikushushana omu bikwato by‘okukyebera ebirikworeka okukora kw‘ekikwato ky‘okukyebera okurikugyeragyeranisibwa.
Okwongyera kuhamya obukuru bwa V-modified Ni(OH)2 omu kwongyera aha kukora kwa COR, tukakora emiringo endiijo ebiri ey’okukora eby’obuhangwa kubaasa kuta V omu bintu bya Ni(OH)2-NS. Omwe n’omuringo gw’okutabura, kandi sampo neemanyirwa aha NiV-MIX; ekindi n’omuringo gw’okukuratana kw’okusheeshasheesha, kandi sampo neeyetwa NiV-SP. Ebirikukwata aha kucondooza nibiheebwa omu kicweka ky‘emiringo y‘okukora. Maapu ya SEM-EDS ekooreka ngu V ekahindurwa gye aha rubaju rwa Ni(OH)2-NS rw’eby’okureeberaho byombi (Ekishushani ky’okwongyeraho 14). Ebirugire omu kucondooza kw’amashanyarazi nibyoreka ngu ahari 1.8 VRHE, obushoboorozi bwa AA aha bikwato bya NiV-MIX na NiV-SP ni 78% na 79%, byombi nibyoreka obushoboorozi bw’ahaiguru kukira Ni(OH)2-NS (51%). Ekindi, OER aha bikwato bya NiV-MIX na NiV-SP ekakyeenwa (FE O2: 7% na 2%, buri kimwe) kugyeragyeranisa na Ni(OH)2-NS (FE O2: 27%). Ebirugiremu ebi nibihamya ebirungi ebirikuruga omu kuhindura V omu Ni(OH)2 aha kuzibira OER (Ekishushani ky‘okwongyeraho 14). Kwonka, okuhama kw’ebikwato ebirikureetaho okuhama kukaba nikuteganisibwa, ekyayorekwa okukyendeera kwa FE AA ahari NiV-MIX kuhika ahari 45% kandi ahari NiV-SP kuhika ahari 35% bwanyima y’enzindo mushanju za COR, ekirikumanyisa ngu nikyetengyesa kutwara emiringo ehikire ey’okuhamira aha miringo ya V, nk’okuhindura Ni( la NiOH-)V omu the NiV- la-2. ekikuru ekirikureetaho omurimo ogu.
Kandi tukashwijuma okuhama kwa Ni(OH)2-NS na NiV-LDH-NS turikuta COR omu nkora nyingi. Okugarukamu kukakorwa kumara 1 h buri nkora kandi amashanyarazi gakagarurwaho bwanyima ya buri nkora. Bwanyima y‘omuringo gwa 7, okukora kwa FE na AA aha Ni(OH)2-NS kukakyendeera n‘ebicweka 50% na 60%, obwo okweyongyera kwa OER kurikureebeka (Fig. 2i, j). Bwanyima ya buri nkora, tukashwijuma enkora ya cyclic voltammetry (CV) y’ebintu ebirikureetaho okuhinduka kandi twareeba ngu enshonga y’okuhindura Ni2+ ekaba neekyendeera mporampora, ekirikworeka okukyendeera kw’obushoboorozi bwa redox bwa Ni (Ekishushani ky’okwongyeraho 15a–c). Ahamwe n‘okwongyera aha Ni cation concentration omu electrolyte omu bwire bw‘okukoresa amashanyarazi (Supplementary Fig. 15d), nituha okusheeshasheesha kw‘okukora (okukyendeera omu kukora kwa FE na AA) ahabw‘okusheeshasheesha kwa Ni kuruga omu nkora y‘okureetaho, ekirikureetaho okushohozibwa kwingi kw‘ekicweka kya Ni foamed ekirikworeka emirimo ya OER. Okutaana n‘ekyo, NiV-LDH-NS ekakyendeeza aha kukyendeera kw‘okukora kwa FE na AA kuhika ahari 10% (ekishushani 2i, j), ekirikworeka ngu okuhindura V kukazibira gye okusheeshasheesha kwa Ni (ekishushani ky‘okwongyeraho 15d). Kubaasa kwetegyereza okuhama okurikwongyerwamu amaani kw’okuhindura V, tukakora okubara kw’ebiteekateeko. Okurugirira aha bihandiiko ebyabandize34,35, empindahinduka ya enthalpy y’omuringo gw’okukyendeeza aha nkora y’okukyendeeza aha nkora y’ebyoma aha rubaju orurikukora rw’ekintu ekirikureetaho okuhinduka neebaasa kukoresibwa nk’ekishoboororo ekihikire okushwijuma okuhama kw’ekintu ekirikureetaho okuhinduka. Nahabwekyo, empindahinduka za enthalpy z’omuringo gw’okukyendeeza aha nkora ya atomu za Ni aha (100) aha mutwe gwa Ni(OH)2-NS na NiV-LDH-NS ezaagarukiremu kwombekwa (NiOOH na NiVOOH, buri kimwe) zikateberezibwa (ebicweka by’okwombeka eky’okureeberaho nibishoboororwa omu Supplementary Fig.2 na Supplementary No1te). Omuringo gw’okukyendeeza eby’ekyoma bya Ni kuruga omu NiOOH na NiVOOH gukashushanisibwa (Ekishushani ky’okwongyeraho 17). Omuhendo gw’amaani g’okukyendeeza aha Ni aha NiVOOH (0.0325 eV) nigukira ogw’aha NiOOH (0.0005 eV), ekirikworeka ngu okuhindura V nikutunguura okuhama kwa NiOOH.
Okuhamya oku OER erikuzibira NiV-LDH-NS, namunonga aha bushoborozi bw‘amaani bw‘anodic, okucondooza kw‘eby‘amashanyarazi okurikutaana (DEMS) kukakorwa kucondooza aha kuhangwa kwa O2 okurikurugiirira aha bushoborozi aha sampo zitari zimwe na zimwe. Ebirugiremu byorekire ngu omu kubura kwa cyclohexanone, O2 aha NiV-LDH-NS ekareebeka aha bushoboorozi bw’okubanza bwa 1.53 VRHE, obwabaire buri ahansi kakye ahari O2 aha Ni(OH)2-NS (1.62 VRHE) (Ekishushani ky’okwongyeraho 18). Ekirugiremu eki nikimanyisa ngu okuzibira OER kwa NiV-LDH-NS omu bwire bwa COR nikubaasa kutabaho ahabw‘emirimo yaayo y‘omunda ey‘ahansi ya OER, ekirikuhikaana n‘oburemeezi bw‘obwire obu oburi ahaiguru kakye omu nkora y‘okusheenya amashanyarazi (LSV) aha NiV-LDH-NS kukira ahari Ni(OHcy)2-pplo1-NSne (Fig.ucno1-NSne) hatariho). Bwanyima y‘okutaho cyclohexanone, okukyerererwa kw‘okutunguuka kwa O2 (okubaasa kuba nikureetwaho oburungi bw‘okwotsya bwa COR) nikushoboorora FE y‘ahaiguru ya AA omu kicweka ky‘obushoboorozi bukye. Ekikuru munonga, obushoboorozi bw‘okutandika kwa OER aha NiV-LDH-NS (1.73 VRHE) nibukyerererwa munonga kukira obw‘aha Ni(OH)2-NS (1.65 VRHE), ekirikuhikaana na FE y‘ahaiguru ya AA na FE y‘ahansi ya O2 ahari NiV-LDH-NS aha bushoboorozi burungi bwingi (ekishushani 2).
Okubaasa kushoboorora gye okutunguuka kw‘okuhindura V, tukashwijuma OER na COR ebirikukora aha Ni(OH)2-NS na NiV-LDH-NS turikupima Tafel slopes zaabo. Nikirungi kumanya ngu oburemeezi oburiho hati omu kicweka kya Tafel niburuga omu kuhinduka kwa Ni2+ kuza ahari Ni3+ omu bwire bw’okukyebera LSV kuruga aha bushoborozi bukye kuza aha bushoborozi bw’ahaiguru. Okukyendeeza aha nkora ya Ni2+ oxidation aha kupima kwa COR Tafel slope, tukabanza twakora oxidation aha 1.8 VRHE kumara edakiika 10 reero twakora ebigyezo bya LSV omu muringo gw‘okugaruka enyima, nikwo kugira ngu, kuruga aha bushoboorozi bw‘ahaiguru kuhika aha bushoboorozi bw‘ahansi (Ekishushani ky‘okwongyeraho 20). Omubaro gwa LSV ogw‘okubanza gukaterezibwa n‘okurihiirira 100% iR kutunga omuhimbo gwa Tafel. Omu kubura kwa cyclohexanone, okushenda kwa Tafel okwa NiV-LDH-NS (41.6 mV dec−1) kukaba kuri ahansi y‘okwa Ni(OH)2-NS (65.5 mV dec−1), ekirikworeka ngu enkora ya OER neebaasa kwongyerwamu amaani ahabw‘okuhindura V (Ekishushani ky‘okwongyeraho 20c). Bwanyima y‘okutaho omubazi gw‘okukyebera, okushenda kwa Tafel okwa NiV-LDH-NS (37.3 mV dec−1) kukaba kuri ahansi y‘okwa Ni(OH)2-NS (127.4 mV dec−1), ekirikworeka ngu okuhindura V kukaba kwine omugasho gw‘okugyendera aha COR ogurikureebwa gye kugyeragyeranisa na OER ey‘okureeberaho (Supp20d). Ebirugiremu ebi nibyoreka ngu n‘obu okuhindura kwa V kuraabe nikutunguura OER kuhika aha rurengo rumwe, nikutunguura munonga COR kinetics, ekirikureetaho okweyongyera kwa FE ya AA.
Kubaasa kwetegyereza okutunguuka kw‘okuhindura V oku aharuguru aha kukora kwa FE na AA, tukata omutima aha kwega kw‘enkora. Ebimwe aha bihandiiko ebyabandize nibyoreka ngu okuhindura heteroatom nikubaasa kukyendeeza aha nkora y’okureetaho obutafaari bw’omubiri (crystallinity) n’okwongyera aha mwanya ogurikukora aha itaka (EAS), obwo nikwo kwongyera aha mubaro gw’emyanya erikukora kandi obwo n’okutunguura emirimo y’ebintu ebirikureetaho okuteerana36,37. Okucondooza aha kubaasa oku, tukakora okupima kwa ECSA tutakatandikire kukora n’enyima y’okukoresa eby’amashanyarazi, kandi ebyarugamu bikooreka ngu ECSA ya Ni(OH)2-NS na NiV-LDH-NS zikaba nizigyeragyeranisibwa (Ekishushani ky’okwongyeraho 21), otabariiremu okukwatwaho kw’obuhango bw’omwanya ogurikukora bwanyima y’okuhindura V aha catalytic enhance.
Okurugirira aha kumanya okurikwikirizibwa omu bantu boona, omu kuhindura kw’amashanyarazi okurikureetwaho Ni(OH)2 kw’eby’okunywa nari ebindi bihingwa ebirimu ebiriisa, Ni(OH)2 neebanza yafeerwa amashanyarazi na purotoni reero bwanyima ekyendeezibwa kuba NiOOH kurabira omu matembezo g’amashanyarazi aha bushoborozi bw’amashanyarazi obumwe38,39,40,4. NiOOH eyahangirwe bwanyima neekora nk’ekika kya COR ekirikukorera kimwe okushohoza haidrojeni n’ebiriisa kuruga omu nkora ya nucleophilic substrate kurabira omu matembezo g’eby’obuhangwa kubaasa kuhanga ekirugiremu ekiine okwijuzibwa20,41. Kwonka, kigambirweho juba ngu n’obu okukyendeeza ahari NiOOH kuraabe nikubaasa kukora nk’eidaara eririkumanyisa omubaro (RDS) ahabw’okuhindura amashanyarazi g’omwonyo aha Ni(OH)2, nk’oku kirikworekwa omu bihandiiko ebihererukireyo, okuhindura amashanyarazi g’omwonyo gwa Ni3+ nikubaasa kuba omuringo gw’okwetunguura kurabira omu kuhindura amashanyarazi agatari ga redox narishi Ni423. Okuhimbisibwa n‘okwega kw‘oburyo okwagambirweho omu bihandiiko nibyo bimwe, tukakoresa omunyugunyu gwa dimethylglyoxime disodium octahydrate (C4H6N2Na2O2 8H2O) nk‘omubazi gw‘okucondooza kubaasa kukwata omu mwanya gwona okuhangwa kwa Ni2+ okurikuruga omu kukyendeeza kwa Ni3+ omu bwire bwa COR (Ekishushani ky‘okwongyeraho No2 n‘eky‘okureeberaho 3). Ebirugiremu byorekire okuhangwa kwa Ni2+, ekirikuhamya ngu okukyendeeza kw’eby’obuhangwa kwa NiOOH n’okuhindura kw’amashanyarazi kwa Ni(OH)2 kukabaho omurundi gumwe omu nkora ya COR. Nahabwekyo, omurimo gw’okureetaho okuhinduka nigubaasa kurugiirira munonga aha nkora ya Ni(OH)2 okukyendeeza kuhika ahari NiOOH. Okurugirira aha musingye ogu, tukakuratiraho kucondooza yaaba okuhindura V nikwija kwongyera aha kukyendeeza kwa Ni(OH)2 kandi obwo kutunguura COR.
Twabanza twakoresa obukoryo bwa Raman omu mwanya kworeka ngu NiOOH n‘omuringo gw‘okukora ogwa COR ahari Ni(OH)2-NS na NiV-LDH-NS turikureeba oku NiOOH erikuhangwa aha bushoboorozi burungi n‘okukoresa kwayo okurikukuratiraho bwanyima y‘okutaho cyclohexurecal” (okukuratira enkora “electrochemiche- 3a). Ekindi, okugarukamu kwa NiV-LDH-NS eyaagarukiremu kwombekwa kukakira okwa Ni(OH)2-NS, nk’oku kirikworekwa omu kubura kw’ahonaaho kw’akamanyiso ka Ni3+–O Raman. Bwanyima tukayoreka ngu NiV-LDH-NS ekooreka obushoboorozi bukye bw‘okukora NiOOH kugyeragyeranisa na Ni(OH)2-NS omu kubaho nari obutabaho bwa cyclohexanone (ekishushani 3b, c n‘ekishushani ky‘okwongyeraho 4c, d). Ekikuru, okukora kwa OER okurikukirayo okwa NiV-LDH-NS nikurugamu ebicupuri bingi ebirikuhamira aha rubaju rw‘omumaisho rw‘ekigyendererwa ky‘okupima Raman, ekirikureetaho enshonga ya Raman ahari 1.55 VRHE kubura (Ekishushani ky‘okwongyeraho 4d). Okurugirira aha byarugamu bya DEMS (Ekishushani ky‘okwongyeraho 18), oburemeezi bw‘obwire obu aha bushoborozi bukye (VRHE < 1.58 ahari Ni(OH)2-NS na VRHE < 1.53 ahari NiV-LDH-NS) nibukira kubaho ahabw‘okugaruka kwombeka Ni2+ ions okukira OER ofnohene omu absc. Nahabwekyo, enshonga y‘okuhindura okwijuzibwa kwa Ni2+ omu nkora ya LSV neekira eya NiV-LDH-NS, ekirikworeka ngu okuhindura kwa V nikuha NiV-LDH-NS obushoboorozi bw‘okugaruzaho (reeba ekishushani ky‘okwongyeraho 19 ahabw‘okushwijuma okuhikire).
a Ebishushani bya Raman eby‘omu mwanya bya Ni(OH)2-NS (aha rubaju rwa bumosho) na NiV-LDH-NS (aha rubaju rwa buryo) ahansi y‘embeera za OCP bwanyima y‘okubanza kuhindura ebiriisa aha 1.5 VRHE omu 0.5 M KOH na 0.4 M cyclohexanone kumara 60 s. b Ebishushani bya Raman eby’omu mwanya ebya Ni(OH)2-NS na c NiV-LDH-NS omu 0.5 M KOH + 0.4 M ebiriisa by’omubiri aha bushoborozi obutarikushushana. d Omu mwanya gwa XANES ebiri omu nkora ya Ni(OH)2-NS na NiV-LDH-NS aha rubaju rwa Ni K omu 0.5 M KOH na e 0.5 M KOH na 0.4 M cyclohexanone. Ekihandiiko ekirimu nikyoreka ekicweka ky’erangi ekihango ahagati ya 8342 na 8446 eV. f Embeera z‘omugasho za Ni omu Ni(OH)2-NS na NiV-LDH-NS aha bushoborozi butarikushushana. g Omu mwanya Ni EXAFS ebishushani bya NiV-LDH-NS bitakatandikire n‘enyima y‘okutaho cyclohexanone aha bushoborozi butari bumwe na bumwe. h Eby‘okureeberaho by‘ebiteekateeko bya Ni(OH)2-NS na NiV-LDH-NS. Ahaiguru: Aha Ni(OH)2-NS, okugaruka omu nkora mpora mpora kuruga ahari Ni(OH)2-NS kuza ahari NiOOH nikukora nka RDS, obwo cyclohexanone erikukyendeeza aha kika kya Ni eky’omuhendo gw’ahaiguru kurabira omu matembezo g’eby’emibazi kubaasa kuguma n’embeera ya Ni ey’omuhendo mukye kubaasa kureetaho AA. Ahansi: Aha NiV-LDH-NS, eitembezo ry‘okugaruzaho nirihwerwa okuhindura kwa V, ekirikureetaho okuhindura RDS kuruga omu idaara ry‘okugaruzaho kuza omu idaara ry‘eby‘emibazi. i Amaani ga Gibbs ag’obuntu nigahinduka aha kugaruka kwombeka Ni(OH)2-NS na NiV-LDH-NS. Ebihandiiko ebitari birungi ebya aj na i nibiheebwa omu fairo y’ebihandiiko ebitari birungi.
Okucondooza aha kutunguuka kw’ebintu by’atomu n’eby’amashanyarazi omu bwire bw’okukyendeeza aha nkora y’okukyendeeza aha nkora y’okukyendeeza aha nshonga, tukakora okucondooza okwa in situ X-ray absorption spectroscopy (XAS), okwahaire ekikwato ky’amaani eky’okucondooza aha nkora y’ebika bya Ni omu mitwe eshatu erikukuratana: OER, okutaho cyclohexanone, na COR aha nkora ya openOCP). Ekishushani nikyoreka K-edge XANES spectra ya Ni n‘obushoboorozi oburikweyongyera bwanyima y‘okuteebwamu omubazi gwa cyclohexanone (ekishushani 3d, e). Omu bushoboorozi nibwo bumwe, amaani g‘okunywanisa aha rubaju rwa NiV-LDH-NS nigakira munonga aga Ni(OH)2-NS (ekishushani 3d, e, inset). Omubaro gw‘ahaiguru gwa Ni ahansi ya buri mbeera gukateberezibwa omu nkora y‘okuteerana kw‘omutindo gw‘ebicweka bya XANES n‘okugaruka enyima kw‘okuhinduka kw‘amaani g‘okunywa Ni K-edge (ekishushani 3f), n‘ebicweka by‘okureeberaho ebyatwarwa kuruga omu bihandiiko ebyashohoziibwe (Ekishushani ky‘okwongyeraho 23)43.
Omu nkora y‘okubanza (etakatandikireho cyclohexanone, erikuhikaana n‘omuringo gwa OER; Ekishushani 3f, aha rubaju rwa bumosho), aha busobozi bw‘ekirungo ekitarikwombekwa (<1.3 VRHE), embeera ya valence ya Ni omu NiV-LDH-NS (+1.83) neebaasa kuba eri ahansi kakye kukira eya Ni(OH+)2). okutwarwa kwa electron kuruga ahari V kuza ahari Ni, okurikuhikaana n’ebyarugamu bya XPS ebyagambwaho ahaiguru (ekishushani 2f). Obushoboorozi bwaba niburenga aha nshonga y‘okukyendeeza (1.5 VRHE), embeera y‘omugasho gwa Ni omu NiV-LDH-NS (+3.28) neeyoreka okweyongyera okurikureebwa gye waagyeragyeranisa n‘okwa Ni(OH)2-NS (+2.49). Aha bushoborozi bw‘ahaiguru (1.8 VRHE), embeera y‘omugasho gw‘ebicweka bya Ni ebitungirwe aha NiV-LDH-NS (+3.64) eri ahaiguru kukira eya Ni(OH)2-NS (+3.47). Okurugirira ahari ripoota ezihererukireyo, omuringo ogu niguhikaana n’okukora ebika bya Ni4+ eby’omuhendo gw’ahaiguru omu nkora ya Ni3+xOOH1-x (Ni3+x n’ebika bya Ni3+ na Ni4+ ebitaine mugasho), ebyabaire byorekire enyimaho emirimo y’okureetaho okutunguuka omu kusheeshasheesha kw’omwonyo38,39,44. Nahabwekyo, okukora kw‘ahaiguru kwa NiV-LDH-NS omu COR nikubaasa kuba nikureetwaho okukyendeeza okurikwongyerwamu amaani kubaasa kuhanga ebika bya Ni eby‘omuhendo gw‘ahaiguru ebirikukora nk‘eby‘okureeberaho.
Omu nkora ya kabiri (okutaho cyclohexanone bwanyima y‘okukinga empeta, ekishushani 3f), embeera y‘omugasho ya Ni aha bikwatiraine n‘okureetaho ebiriisa byombi ekakyendeera munonga, ekirikuhikaana n‘omuringo gw‘okukyendeeza Ni3+xOOH1-x ahabw‘okukoresa cyclohexanone, ekirikuhikaana n‘ebyarugamu omu kucondooza kwa in situ Raman embeera y‘omugasho kuhika ahari Niver al spectroscopy ya (ekishushani 3f). embeera y‘okubanza (eidaara ry‘okubanza aha bushoboorozi bukye), ekirikworeka okugaruka enyima kw‘omuringo gw‘okugaruzaho Ni kuza ahari Ni3+xOOH1-x.
Omu nkora ya COR (enkora ya COR) aha bushoborozi bwa COR (1.5 na 1.8 VRHE; ekishushani 3f, aha rubaju rwa buryo), embeera ya valence ya Ni omu Ni(OH)2-NS ekeyongyera kakye (+2.16 na +2.40), ekiri ahansi munonga kukira aha bushoborozi nibwo bumwe omu nkora y‘okubanza (+2.47 na +3). Ebirugiremu ebi nibyoreka ngu bwanyima y‘okuteebwamu cyclohexanone, COR neekyendeezibwa omu nkora y‘okugyendera ahabw‘okuhinduka mpora mpora kwa Ni2+ kuhika ahari Ni3+x (nikwo kugira ngu, okugaruka kwombeka Ni) okukira aha ntambwe y‘eby‘obuhangwa ahagati ya NiOOH na cyclohexanone ahari Ni(OH)2-NS, ekirikureka Ni omu mbeera y‘omuhendo mukye. Nahabwekyo, nituhendera ngu okugaruka kwombeka Ni nikubaasa kukora nka RDS omu nkora ya COR ahari Ni(OH)2-NS. Okutaana n‘ekyo, NiV-LDH-NS ekaguma eine omuhendo gw‘ahaiguru munonga gw‘ebika bya Ni (>3) omu bwire bw‘omuringo gwa COR, kandi omuhendo gukeyongyera munonga (ahansi ya 0.2) kugyeragyeranisa n‘eidaara ry‘okubanza aha bushoboorozi nibwo bumwe (1.65 na 1.8 VRHE), ekirikworeka ngu okuhindura V kinetically the fax Ni+ kukyendeeza aha nkora ya Ni3. okukira eitembezo ry’eby’emibazi ry’okukyendeeza aha cyclohexanone. Ebirugire omu kucondooza kwa X-ray okuyongyeirweho (EXAFS) nabyo bikooreka okuhinduka okuhikire kw’enkoragana ya Ni–O (kuruga ahari 1.6 kuhika ahari 1.4 Å) na Ni–Ni(V) (kuruga ahari 2.8 kuhika ahari 2.4 Å) omu kubaho kwa cyclohexanone. Eki nikikwatagana n’okugaruka kwombeka omutindo gwa Ni(OH)2 kuza omu muring gwa NiOOH n’okukyendeeza kw’eby’emibazi omu muringo gwa NiOOH ahabw’okukoresa cyclohexanone (Fig. 3g). Kwonka, cyclohexanone ekaremesa munonga okukyendeeza aha nkora ya Ni(OH)2-NS (reeba Ekihandiiko ky‘okwongyeraho 4 n‘ekishushani ky‘okwongyeraho 24 ahabw‘ebindi).
Okutwarira hamwe, aha Ni(OH)2-NS (Fig. 3h, ahaiguru), eitembezo ry‘okukyendeeza mpora kuruga aha Ni(OH)2 kuza aha NiOOH niribaasa kukora nka RDS y‘omuringo gwa COR gwona okukira eitembezo ry‘eby‘obuhangwa ry‘okukora AA kuruga omu cyclohexanone omu bwire bw‘okukyendeeza kw‘eby‘obuhangwa bwa NiOOH. Aha NiV-LDH-NS (Fig. 3h, ahansi), okuhindura kwa V nikutunguura enkora ya oxidation kinetics ya Ni2+ kuhika ahari Ni3+x, obwo nikutunguura okukora kwa NiVOOH (omu mwanya gw‘okukoresa ahabw‘okukyendeeza aha by‘emibazi), ekirikuhindura RDS kuza aha ntambwe y‘eby‘obuhangwa. Kubaasa kwetegyereza okugaruka kwombeka kwa Ni okurikureetwaho okuhindura kwa V, tukakora okubara okundi okw’ebiteekateeko. Nkoku kirikworekwa omu kishushani 3h, tukagyeragyeranisa omuringo gw’okugaruka kwombeka Ni(OH)2-NS na NiV-LDH-NS. Ebibiina bya lattice hydroxyl ebiri aha Ni(OH)2-NS na NiV-LDH-NS nibirugaho purotoni ahabw’okushohoza OH- omu nkora y’amashanyarazi kubaasa kuhangaho oxygen ya lattice etariho amashanyarazi. Ebirikuhikaana n’eby’emibazi nibishushana n’ebi:
Empindahinduka y‘amaani ga Gibbs ey‘obuntu ey‘okugaruka kwombeka ekabarwa (ekishushani 3i), kandi NiV-LDH-NS (0.81 eV) ekooreka empindahinduka y‘amaani ga Gibbs ey‘obuntu nkye munonga kukira Ni(OH)2-NS (1.66 eV), ekirikworeka ngu okuhindura kwa V kukakyendeeza aha amaani agarikwetengyesa omu kugaruka kwombeka Ni. Nitwikiriza ngu okutunguura okugaruka kwombeka nikubaasa kukyendeeza aha nkora y‘okuzibira amaani ga COR yoona (reeba okwega kw‘omuringo gw‘okugarukamu ahaifo ahabw‘ebirikukiraho), obwo nikwo kutunguura okugarukamu aha nkora y‘okugarukamu y‘ahaiguru.
Okweshwijuma oku aharuguru nikworeka ngu okuhindura kwa V nikureetaho okugaruka omu ntebeekanisa y’omutindo gwa Ni(OH)2 omu bwangu, obwo nikwo kwongyera aha nkora y’okugarukamu kandi, omu kugarukamu, oburemeezi bw’obwire bwa COR. Kwonka emyanya ya Ni3+x nayo neebaasa kutunguura omurimo gwa OER. Kuruga omu nkora ya LSV etaine cyclohexanone, nikireebeka ngu oburemeezi bw‘obwire obu bwa NiV-LDH-NS buri ahaiguru kukira obwa Ni(OH)2-NS (Ekishushani ky‘okwongyeraho 19), ekirikureetaho enkora ya COR na OER kukora enkora z‘okuhakanisa. Nahabwekyo, FE y‘ahaiguru munonga eya AA kukira eya NiV-LDH-NS terikubaasa kushoboororwa omu bwijwire ahabw‘okuhindura kwa V okurikutunguura okugaruka omu ntebeekanisa y‘omutindo.
Nikikirizibwa omu bwijwire ngu omu nkora ya alkaline, ebikorwa by’amashanyarazi eby’ebicweka by’omubiri ebirikukora nk’eby’okurya nibikuratira omuringo gwa Langmuir–Hinshelwood (LH). Omu bwijwire, substrate na OH− anions nizihakanisana coadsorbed aha rubaju rw’ekirikureetaho, kandi OH− erikukwatwaho neehindurwa omu guruupu z’amaizi ezirikukora (OH*), ezirikukora nk’ebiriisa by’amashanyarazi ahabw’okuhindura nucleophiles, omuringo ogwabandize kworekwa omu kubara, data444. Nahabwekyo, okuteerana kw’ebintu ebirikukora n’omubaro gwabyo (organic substrate na OH−) nibibaasa kutegyeka okukingira kw’ebintu ebirikukora aha mutwe gw’ekintu ekirikureetaho, obwo nibikwata ahari FE n’okutunga ekirugiremu ekigyendereirwe14,48,49,50. Omu mbeera yaitu, nituteekateeka ngu okukingira kw‘ahaiguru kwa cyclohexanone omu NiV-LDH-NS nikukunda enkora ya COR, kandi ekirikushushana, okukingira kw‘ahansi kwa cyclohexanone omu Ni(OH)2-NS nikukunda enkora ya OER.
Okugyezaho enteekateeka egi aharuguru, tukabanza twakora okucondooza kwa kabiri okurikukwata aha kuteerana kw’ebintu ebirikukora (C, cyclohexanone, na COH−). Okugyezesa okwabandize kukakorwa n’okukoresa amashanyarazi aha bushoboorozi obutarikuhinduka (1.8 VRHE) aha bikwato bya Ni(OH)2-NS na NiV-LDH-NS ebiine ebiriisa bya cyclohexanone C ebitarikushushana (0.05 ~ 0.45 M) n’ebiriisa bya COH− ebitarikuhinduka (0.5 M). Bwanyima, obukomooko bwa FE na AA bukabarwa. Aha nkora ya NiV-LDH-NS, akakwate akari ahagati y’okutunga AA na cyclohexanone C kakayoreka omuringo gw’omutaano “gw’omuringo gw’enshozi” omu muringo gwa LH (Fig. 4a), ekirikworeka ngu okukingira kwa cyclohexanone okuri ahaiguru nikuhakanisa okushohoza OH−. Obwire obu ahari Ni(OH)2-NS, AA erikurugamu ekeyongyera omu muringo gumwe n’okwongyera kwa C ya cyclohexanone kuruga ahari 0.05 kuhika ahari 0.45 M, ekirikworeka ngu n’obu omubaro gw’ebintu bingi ogwa cyclohexanone gwabaire guri ahaiguru (0.45 M), okukingira kwayo aha mutwe kukaba kukiri ahansi munonga. Okwongyera ahari ekyo, n’okwongyera ahari COH− kuhika ahari 1.5 M, “omuringo gw’enshozi” gukareebeka ahari Ni(OH)2-NS kurugiirira ahari C ya cyclohexanone, kandi enshonga y’okuhindura kw’okukora ekakyerererwa kugyeragyeranisa na NiV-LDH-NS, ekirikwongyera kuhamya okushohoza okukye okwa Ni(NSuhexano) 25a n’Ekihandiiko 5). Okwongyera ahari ekyo, FE ya AA aha NiV-LDH-NS ekaba neehurira munonga C-cyclohexanone kandi ekeyongyera juba kuhika ahari 80% obu C-cyclohexanone yaayeyongyera kuruga ahari 0.05 M kuhika ahari 0.3 M, ekirikworeka ngu cyclohexanone ekaba neetunga obugaiga bwanguhi ahari NiV-LDH-LDH). Okutaana n’ekyo, okwongyera aha nkora ya C-cyclohexanone tikuremeise munonga OER ahari Ni(OH)2-NS, ekirikubaasa kuba nikireetwaho okubura okunywanisa kwa cyclohexanone okurikumara. Okutaana n‘ekyo, okucondooza okurikukiraho aha kurugiirira kwa COH− aha nkora y‘okureetaho okuhinduka kw‘ebintu nakyo kikahamya ngu okushohoza kwa cyclohexanone kukaba kurungi waagyeragyeranisa na NiV-LDH-NS, eyabaire neebaasa kugumisiriza COH− y‘ahaiguru omu bwire bw‘omuringo gwa COR hatariho kukyendeeza FE ya AA (Supplementary c5b and 25te).
Okukora kwa AA na EF kwa b Ni(OH)2-NS na NiV-LDH-NS aha nkora y‘okukyebera erimu C etari emwe n‘emwe omu 0.5 M KOH. c Amaani g’okushohoza ebiriisa by’omubiri aha NiOOH na NiVOOH. d FE ya AA aha Ni(OH)2-NS na NiV-LDH-NS omu 0.5 M KOH na 0.4 M cyclohexanone aha 1.80 VRHE barikukoresa enkora z‘obushoboorozi ezitarikugumizamu n‘ezitarikuhinduka. Enshobi z‘emibaro nizijwekyera okutaana kw‘omutindo gw‘ebipimo bishatu eby‘okwetongora barikukoresa sampo emwe kandi ziri omu 10%. e Ahaiguru: Aha Ni(OH)2-NS, cyclohexanone erimu omwanya mukye C neekwatwaho cyclohexanone omu muringo gw’amaani, ekirikureetaho okurwanagana kw’amaani ahabwa OER. Ahansi: Aha NiV-LDH-NS, okuteerana kw‘ahaiguru kw‘eitaka kw‘ekirungo kya cyclohexanone C nikureebeka n‘okwongyera aha kunywanisa kwa cyclohexanone, ekirikureetaho okuzibira OER. Ebihandiiko ebitahikire ebya a–d nibiheebwa omu fairo y’ebihandiiko ebitahikire.
Okugyezaho okutunguuka kw’okushohoza kwa cyclohexanone ahari NiV-LDH-NS, tukakoresa amashanyarazi g’okuteerana (E-QCM) kureeba okuhinduka kw’obuhango bw’ebika by’okushohoza omu bwire obwabuzima. Ebirugiremu byorekire ngu obushoboorozi bw‘okubanza obw‘okushohoza cyclohexanone ahari NiV-LDH-NS bukaba buri bwingi emirundi 1.6 kukira obw‘aha Ni(OH)2-NS omu mbeera ya OCP, kandi entaaniso egi omu bushoborozi bw‘okushohoza ekeyongyera kweyongyera nk‘oku obushoboorozi bwabaire nibweyongyera kuhika ahari 1.5 VRHE (Ekishushani ky‘okwongyeraho 26). Okubara kwa DFT okwa spin-polarized kukakorwa kucondooza aha mitwarize y’okushohoza ebiriisa bya cyclohexanone ahari NiOOH na NiVOOH (ekishushani 4c). Cyclohexanone neekwatanisa aha Ni-ahagati ahari NiOOH n’amaani g’okukwaata (Eads) ga -0.57 eV, obwo cyclohexanone neebaasa kukwaata aha Ni-ahagati nari V-ahagati ahari NiVOOH, ahu V-ahagati erikuhereza Eads eziri ahansi munonga ezitarikuhinduka (e) eza-06. ekirungo kya NiVOOH.
Okwongera kuhamya ngu okutunguuka kw’okushohoza kwa cyclohexanone nikubaasa kutunguura okukora kwa AA n’okuzibira OER, tukakoresa enkora y’obushoboorozi obutarikugumizamu kugaigahaza cyclohexanone aha rubaju rw’ekirikureetaho (ahabwa Ni(OH)2-NS na NiV-LDH-NS), eyaabaire neehimbisibwa na previous. 51, 52 Buzima, tukataho obushoboorozi bwa 1.8 VRHE ahari COR, reero twabuhindura omu mbeera ya OCP, reero twabuhindura twagaruka twaza omu 1.8 VRHE. Omu muringo ogu, cyclohexanone neebaasa kwerundaana aha rubaju rw‘ekirungo omu mbeera ya OCP ahagati y‘amashanyarazi (reeba ekicweka ky‘emiringo ahabw‘enkora eziri omu bwijwire). Ebirugiremu byorekire ngu ahari Ni(OH)2-NS na NiV-LDH-NS, okukoresa amashanyarazi g‘obushoboorozi obutarikugumizamu kukatunguura okukora kw‘eby‘okureeberaho kugyeragyeranisa n‘okukoresa amashanyarazi g‘obushoboorozi obutarikuhinduka (ekishushani 4d). Ekikuru, Ni(OH)2-NS ekooreka okutunguuka kw‘amaani omu COR (AA FE: kuruga ahari 51% kuhika ahari 82%) n‘okuzibira OER (O2 FE: kuruga ahari 27% kuhika ahari 4%) kukira NiV-LDH-NS, ekyabaire nikirugiirira aha nshonga ngu okuteerana kwa cyclohexanone okurikukirayo aha kutunguuka kw‘omubiri kukaba nikubaasa kuba . obushoboorozi bw‘okushohoza (nikwo kugira ngu, Ni(OH)2-NS) ahabw‘okukoresa amashanyarazi g‘obushoboorozi oburikubaho omu bwire.
Okutwarira hamwe, okuzibira OER ahari NiV-LDH-NS nikubaasa kuba nikureetwaho okutunguuka kw‘okushohoza kwa cyclohexanone (ekishushani 4e). Aha Ni(OH)2-NS (ekishushani 4e, ahaiguru), okushohoza okukye kwa cyclohexanone kukarugamu okukingira kwa cyclohexanone okukye munonga n’okukingira kwa OH* kwingi munonga aha rubaju rw’ekirungo. Nahabwekyo, ebika bya OH* ebirengire nibiija kureetera okurwana kw‘amaani ahabwa OER kandi bikyendeeze FE ya AA. Okutaana n‘ekyo, aha NiV-LDH-NS (ekishushani 4e, ahansi), okuhindura kwa V kukongyera aha bushoborozi bw‘okushohoza cyclohexanone, obwo kwongyera aha C y‘ahaiguru ya cyclohexanone kandi kukoresa gye ebika bya OH* ebishohoziibwe ahabwa COR, okutunguura okukora kwa AA n‘okuzibira.
Oyihireho okucondooza aha nkora y‘okuhindura V aha kugaruka kwombeka ebika bya Ni n‘okushohoza cyclohexanone, tukacondooza n‘okureeba yaaba V neehindura omuhanda gw‘okukora AA kuruga omu COR. Emihanda mingi etari emwe n‘emwe eya COR etebekanisiibwe omu bihandiiko, kandi tukashwijuma okubaasa kwayo omu nkora yaitu y‘okugarukamu (reeba ekishushani ky‘okwongyeraho 27 n‘eky‘okureeberaho ky‘okwongyeraho 6 ahabw‘ebindi)13,14,26. Eky‘okubanza, kigambirwe ngu eitembezo ry‘okubanza ry‘omuhanda gwa COR niribaasa kubamu okubanza kw‘okuhindura ebiriisa bya cyclohexanone kubaasa kuhanga ekikuru eky‘ahagati 2-hydroxycyclohexanone (2)13,14. Okuhamya enkora, tukakoresa 5,5-dimethyl-1-pyrrolidine N-oxide (DMPO) kukwaata ebiri ahagati y’ebintu ebirikukora ebirikukwatwa aha mutwe gw’ekintu ekirikureetaho okuhinduka kandi twacondooza aha EPR. Ebirugire omu kucondooza kwa EPR bikooreka okubaho kw’ebicweka bya C-centred (R ) n’ebicweka bya hydroxyl (OH ) aha bikwatiraine n’ebicweka byombi omu bwire bw’omuringo gwa COR, ekirikworeka ngu okusheeshasheesha kwa Cα − H okwa cyclohexanone nikureetaho ekicweka kya enolate eky’omugati (1), ekirikugaruka kigaruka kihindurwa OH (Fig2Fig.5). 28). N‘obu ebikwato by‘ahagati nibyo bimwe byamanyirwe aha bikwatiraine n‘okureetaho ebiriisa byombi, ekicweka ky‘omwanya ky‘akamanyiso ka R ahari NiV-LDH-NS kikaba kiri ahaiguru munonga kukira ekya Ni(OH)2-NS, ekirikubaasa kuba nikireetwaho obushoboorozi bw‘okunywanisa oburikwongyerwaho bwa cyclohexanone (Ekipande ky‘okwongyeraho 3 n‘Ekihandiiko 7). Twongyeire twakoresa 2 na 1,2-cyclohexanedione (3) nk’ebintu ebirikutandika kuhindura amashanyarazi kugyezaho yaaba V neija kuhindura eitembezo ry’okuhindura ebiriisa eririkukuratiraho. Ebirugire omu kucondooza kw‘amashanyarazi g‘ebintu ebirikubaasa kuba eby‘omugati (2 na 3) ahari Ni(OH)2-NS na NiV-LDH-NS bikooreka okutoorana kw‘ebintu okurikugyeragyeranisibwa, ekirikworeka ngu okugarukamu kwa COR ahari Ni(OH)2-NS nari NiV-LDH-NS kukagumizamu kurabira omu mihanda erikushushana (ekishushani 5b). Ekindi, AA ekaba eri ekirugiremu ekikuru kyonka obu 2 yaakoresiibwe nk’ekirikugarukamu, ekirikumanyisa ngu AA ekatunga kurabira omu nkora y’okuhindura ebiriisa butoosha kurabira omu kusharaho Cα − Cβ bond ya 2 omu mwanya gw’okuhindura ebiriisa ebirikukurataho kuhika ahari 3 aha bikwatiraine n’ebintu byombi, ahabw’okuba ekaba neehindurwa munonga kuba GA obu ekirungo kya 3 kyabaire nikitandika (Figure theppacd2). 30).
EPR akamanyiso ka NiV-LDH-NS omu 0.5 M KOH + 0.4 M ekirungo ky‘omubiri. b Ebirugire omu kucondooza kw’amashanyarazi okwa 2-haidrokisicycloheksanone (2) na 1,2-cyclohexanedione (3). Okukyebera kw’amashanyarazi kukakorwa omu 0.5 M KOH na 0.1 M 2 nari 3 ahari 1.8 VRE kumara eshaaha emwe. Enshobi z’emibaro nizijwekyera okutaana kw’omutindo gw’ebipimo bibiri eby’okwetongora barikukoresa ekirikureetaho kimwe. c Emihanda y‘okugarukamu etebekanisiibwe eya COR aha bikwatiraine n‘okureetaho ebiriisa bibiri. d Ekishushani ky‘omuringo gw‘omuhanda gwa COR aha Ni(OH)2-NS (aha rubaju rwa bumosho) na d NiV-LDH-NS (aha rubaju rwa buryo). Obushaarizi oburikwiragura nibworeka amatembezo agu okuhindura kwa V kurikutunguura omu nkora ya COR. Ebihandiiko ebitahikire ebya a na b nibiheebwa omu fairo y‘ebihandiiko ebitahikire.
Okutwarira hamwe, tukooreka ngu Ni(OH)2-NS na NiV-LDH-NS nizireetaho COR kurabira omu muhanda nigwo gumwe: cyclohexanone neekwatwa aha mutwe gw’ekirikureetaho, esheesheka kandi efeerwa obutafaari bw’omubiri (electrons) kuhanga 1, erikukuratirwa OH* kureetaho entunguuka nyingi toFig5AA). Kwonka, cyclohexanone ku yaakozesiibwe nk’ekirungo, okurwanagana kwa OER kukareebeka ahari Ni(OH)2-NS yonka, obwo omubaro gw’omwika ogurikukirayo obukye gurikuteeranirwa hamwe obu 2 na 3 zaakoresiibwe nk’ekirungo. Nahabwekyo, entaaniso ezireebirwe omu kukora kwa katatali nizibaasa kuba niziruga omu mpindahinduka omu nkora y‘okuzibira amaani ga RDS n‘obushoboorozi bw‘okutwara cyclohexanone oburikureetwaho okuhindura kwa V okukira empindahinduka omu muhanda gw‘okugarukamu. Nahabwekyo tukashwijuma RDS y‘emihanda y‘okugarukamu aha bikwatiraine n‘ebintu byombi. Ebirugire omu kucondooza kwa in situ X-ray acoustic spectroscopy ebyagambwaho ahaiguru nibyoreka ngu okuhindura kwa V nikuhindura RDS omu nkora ya COR kuruga aha rurengo rw‘okugaruka kwombeka kuza aha rurengo rw‘eby‘obuhangwa, kuguma n‘omutindo gwa NiOOH n‘ebika bya Ni eby‘omuhendo gw‘ahaiguru bitaine kabi koona aha NiV-LDH-NS (ekishushani 3f, Ekishushani ky‘okwongyeraho No4). Twongyeire twashwijuma emiringo y‘okugarukamu erikworekwa oburemeezi bw‘obwire obu omu buri kicweka ky‘ebicweka by‘obushoboorozi ebitarikushushana omu bwire bw‘okupima CV (reeba ekishushani ky‘okwongyeraho 31 n‘ekihandiiko 8 ahabw‘ebirikukiraho) kandi twakora okucondooza kwa H/D kinetic isotope exchange, ebyabaire nibyoreka hamwe ngu aha RDSVOR-involge ya C . Cα − H bond omu nkora y‘eby‘obuhangwa okukira aha nkora y‘okukyendeeza (reeba ekishushani ky‘okwongyeraho 32 n‘ekihandiiko 8 ahabw‘ebindi).
Okurugirira aha kweshwijuma oku aharuguru, ebirikuruga omu kuhindura V byona nibyorekwa omu kishushani 5d. Ni(OH)2-NS na NiV-LDH-NS ebirikureetaho okugaruka kwombekwa aha itaka aha bushoborozi bw‘ahaiguru bw‘anodic kandi nibireetaho COR kurabira omu muhanda nigwo gumwe. Aha Ni(OH)2-NS (ekishushani 5d, aha rubaju rwa bumosho), eitembezo ry‘okugaruka kwombeka ni RDS omu bwire bw‘enkora ya COR; obwo aha NiV-LDH-NS (ekishushani 5d, aha rubaju rwa buryo), okuhindura V kukatunguura munonga omuringo gw‘okugaruka kwombeka kandi kwahindura RDS omu Cα−H dehydrogenation ya cyclohexanone kubaasa kuhanga 1. Okwongyera ahari ekyo, okushohoza cyclohexanone kukabaho aha mwanya gwa V kandi kukahwera aha su- LDHER, p-.
Okuteekateeka aha kukora gye kw‘amashanyarazi ga NiV-LDH-NS n‘ebiri ahaiguru aha nkora mpango y‘obushoboorozi, tukakora MEA kubaasa kuhikiiriza okukora AA okutarikuhwaho. MEA ekateeranirwa hamwe barikukoresa NiV-LDH-NS nk’anode, PtRu/C ey’obushuubuzi nk’ekyoma53 n’ekibumbe ky’okuhindura anion (omuringo: FAA-3-50) (ekishushani 6a n’ekishushani ky’okwongyeraho 33)54. Ahabw‘okugira ngu amashanyarazi g‘obutafaari gakakyendeera kandi FE ya AA ekaba neegyeragyeranisibwa na 0.5 M KOH omu kucondooza oku aharuguru, okuta omutima aha anolyte kukabonezibwa kuhika ahari 1 M KOH (Ekishushani ky‘okwongyeraho 25c). Ebishushani bya LSV ebihandiikirwe nibyorekwa omu kishushani ky‘okwongyeraho 34, ebirikworeka ngu oburungi bwa COR bwa NiV-LDH-NS buri ahaiguru munonga kukira obwa Ni(OH)2-NS. Okworeka obukuru bwa NiV-LDH-NS, okucondooza kw‘amashanyarazi agatarikuhinduka kukakorwa n‘oburemeezi bw‘amashanyarazi kuruga ahari 50 kuhika ahari 500 mA cm−2 kandi amashanyarazi g‘obutafaari agarikuhikaana gakahandiikwa. Ebirugiremu nibyoreka ngu NiV-LDH-NS ekooreka amaani g’obutafaari ga 1.76 V aha nkora y’amaani g’obwire obu 300 mA cm−2, eyaabaire eri nk’ebicweka 16% ahansi y’eya Ni(OH)2-NS (2.09 V), ekirikworeka ngu eine amaani maingi omu kuhanga AA (Fig. 6b).
Ekishushani ky’okugyendera aha battery. b Amashanyarazi g‘obutafaari hatariho kugarurwaho kwa iR ahari Ni(OH)2-NS na NiV-LDH-NS omu 1 M KOH na 0.4 M cyclohexanone aha nkora z‘amashanyarazi zitari zimwe na zimwe. c AA na FE nizireeta aha Ni(OH)2-NS na NiV-LDH-NS aha nkora zitari zimwe na zimwe z‘obwire obu. Enshobi z’emibaro nizijwekyera okutaana kw’omutindo gw’ebipimo bibiri eby’okwetongora barikukoresa ekirikureetaho kimwe. d Okugyeragyeranisa okukora kw‘eby‘okureeberaho by‘emirimo yeitu n‘enkora ezindi ezaagambirweho ezirikugyendera aha battery14,17,19. Ebirikukwata aha kugarukamu n‘emitwarize y‘okugarukamu bihandiikirwe omu bwijwire omu kipande ky‘okwongyeraho 2. e Amashanyarazi g‘obutafaari na FE ya AA aha NiV-LDH-NS ahari 200 na 300 mA cm−2 omu kugyezibwa kw‘obwire buraingwa, nk‘oku biri. Ebihandiiko ebitari birungi ebya be nibiheebwa nka fairo y‘ebihandiiko ebitari birungi.
Omu bwire obwo, nk‘oku kirikworekwa omu kishushani 6c, NiV-LDH-NS omu kubanza ekaguma eine FE nungi (83% kuhika 61%) aha nkora y‘okushohoza ebiriisa (200 kuhika 500 mA cm-2), obwo erikutunguura okukora kwa AA (1031 kuhika 1900 μmol cm-2 h-1). Omu bwire obwo, 0.8% zonka eza adipic acid anions zikareebeka omu kishengye kya katodi bwanyima y’okukoraho amashanyarazi, ekirikworeka ngu okuhinduka kwa cyclohexanone kukaba kutari kukuru omu mbeera yaitu (Ekishushani ky’okwongyeraho 35). Okutaana n’ekyo, n’omubaro nigwo gumwe ogw’okwongyezibwaho kw’obuhango bw’obwire obu, FE ya AA aha Ni(OH)2-NS ekakyendeera kuruga ahari 61% kuhika ahari 34%, ekyareeteire kyaguma kutunguura okukora kwa AA (762 kuhika ahari 1050 μmol cm-2 h-1). Okukira munonga, okukora kwa AA nangwa n‘okukyeera kakye ahabw‘okuhakanisa kw‘amaani kuruga omu OER, kandi n‘ahabw‘ekyo FE ya AA ekakyendeera munonga n‘okwongyera aha nkora y‘obwire obu (kuruga ahari 200 kuhika ahari 250 mA cm−2, Supplementary Fig. 5). Okurugiirira aha kumanya kwaitu, ebyarugamu omu kuhindura ebiri omu nkora y‘okukoresa MEA n‘ebikwato bya NiV-LDH-NS nibikira munonga okukora kw‘ebikwato by‘okusheeshasheesha ebyabaire byagambirweho enyima n‘ebikwato by‘okusheeshasheesha ebirikwegamira ahari Ni (Ekipande ky‘okwongyeraho 2). Ekindi, nk’oku kirikworekwa omu kishushani 6d, NiV-LDH-NS ekooreka oburungi bw’amaani omu kureeba obuhango bw’amashanyarazi, amaani g’obutafaari, na FE ya AA kugyeragyeranisa n’ekintu ekirikukorera gye Co-based, nikwo kugira ngu, Co3O4 (Co3O4/GDY)17 erikushagikwa graphene. Okwongyera ahari ekyo, tukashwijuma okukoresa amaani g‘okukora AA kandi twayoreka ngu okukoresa AA kukaba kuri kukye munonga, 2.4 W h gAA-1 yonka aha nkora y‘amaani g‘obwire obu eya 300 mA cm-2 n‘amaani g‘obutafaari 1.76 V (okubara okuhikire nikuheebwa omu kihandiiko ky‘okwongyeraho 1). Kugyeragyeranisa n‘ebyarugamu ebirungi ebya 4.1 W h gAA-1 ahabwa Co3O4/GDY ebyagambirweho enyima, okukoresa amaani g‘okukora AA omu murimo gwaitu kukakyendeera n‘ebicweka 42% kandi okukora kukaba kweyongyera emirundi 4 (1536 vs. 319 μmol cm-2 h-1)17.
Okuhama kw‘ekirungo kya NiV-LDH-NS eky‘okukora AA kumara obwire buraingwa omu MEA kukakyeberwa aha nkora y‘obwire obu eya 200 na 300 mA cm-2, nk‘oku biri (ekishushani 6e). Ahabw‘okugira ngu OH− neekoresibwa juba aha nkora y‘amashanyarazi eri ahaiguru, omubaro gw‘okugaruza busya kw‘amashanyarazi ahari 300 mA cm-2 nigukira ogw‘aha 200 mA cm-2 (reeba akacweka kakye “Ebipimo by‘amashanyarazi” ahabw‘ebirikukiraho). Aha nkora ya 200 mA cm-2, omubaro gw‘oburungi bwa COR bukaba buri 93% omu shaaha 6 z‘okubanza, bwanyima bukakyendeera kakye kuhika ahari 81% bwanyima y‘eshaha 60, obwo amaani g‘obutafaari garikweyongyera kakye na 7% (kuruga ahari 1.62 V kuhika ahari 1.73 V), ekirikworeka okuhama kurungi. Obwire obu obuhango bw‘amashanyarazi bwayeyongyera kuhika ahari 300 mA cm−2, oburungi bwa AA bukaguma haihi butahindukire (bukakyendeera kuruga ahari 85% kuhika ahari 72%), kwonka amaani g‘obutafaari gakeyongyera munonga (kuruga ahari 1.71 kuhika ahari 2.09 V, ekirikuhikaana na 22%) omu bwire bw‘okukyebera (Figuree). Nituteekateeka ngu enshonga nkuru ahabw‘okukyendeeza aha kukora n‘okusheenyagura kw‘omubiri gw‘okuhindura anion (AEM) ahabw‘okukoresa cyclohexanone, ekirikureetaho okweyongyera kw‘okuzibira kw‘obutafaari n‘amaani g‘obutafaari bw‘amashanyarazi (Ekishushani ky‘okwongyeraho 36), ekirikuhererukayo n‘okusheeshasheesha kakye kw‘amashanyarazi kuza omu anode n‘okusheeshasheesha kw‘omubaro kuruga omu anode kuza omu ca . okurekyera aho okukoresa amashanyarazi. Okwongyera ahari ekyo, okukyendeera kwa FE ya AA nakwo nikubaasa kuba nikureetwaho okusheeshasheesha kw’ebintu ebirikureetaho okusheeshasheesha, ekirikukunda okukingura kwa Ni foam ahabwa OER. Okworeka oku AEM erimu obuzibu erikukwata aha kusheeshasheesha kw’okuhama aha 300 mA cm−2, tukagihindura AEM ensya bwanyima y’eshaaha 46 z’okukoresa amashanyarazi. Nk‘oku kyabaire nikiteekateekwaho, obushoboorozi bw‘okureetaho okuhinduka bukagarukaho gye, n‘amaani g‘obutafaari gakakyendeera munonga kuhika aha muheendo gw‘okubanza (kuruga ahari 2.09 kuhika ahari 1.71 V) reero gakyeyongyera kakye omu shaaha 12 ezirikukurataho z‘okukyendeeza aha nkora y‘amashanyarazi (kuruga ahari 1.71 kuhika ahari 1.79 V; okweyongyera kwa65).
Okutwarira hamwe, tukabaasa kutunga 60 h y‘okugumaho kw‘okukora AA aha nkora y‘okukora 200 mA cm−2, ekirikworeka ngu FE n‘amaani g‘obutafaari bwa AA nibigumibwaho gye. Kandi tukagyezaho oburemeezi bw‘amaani bw‘amaani bwa 300 mA cm−2 kandi twatunga okuhama kwona okwa 58 h, twahindura AEM n‘ensya bwanyima ya 46 h. Okucondooza oku aharuguru nikworeka okuhama kw‘ekintu ekirikureetaho okuhinduka kandi nikworeka gye ekyetengo ky‘okutunguura omu biro by‘omumaisho AEMs z‘amaani maingi kutunguura okuhama kw‘obwire buraingwa okwa MEA ahabw‘okugumizamu n‘okukora AA aha nkora z‘amaani ezihikire omu by‘amakorero.
Okurugirira aha kukora kwa MEA yaitu, tukateekateeka aha nkora y‘okukora AA ehikire erimu okuriisa eby‘okurya by‘ahansi, okukoresa amashanyarazi, okutaho obutafaari, n‘ebicweka by‘okwahukana (Ekishushani ky‘okwongyeraho 37). Okushwijuma okubanza okw‘okukora kukakorwa kukyebera okubaasa kw‘eby‘entasya kw‘enkora egi barikukoresa omuringo gw‘okukora amashanyarazi g‘eby‘okurya ebirimu alkaline55. Omu muringo ogu, esente nizitwariramu esente z‘okutandikaho, emirimo, n‘ebintu (ekishushani 7a n‘ekishushani ky‘okwongyeraho 38), kandi esente ezirikuruga omu kukora AA na H2. Ebirugire omu TEA nibyoreka ngu omu mbeera zaitu z‘okukora (oburemeezi bw‘obwire obu 300 mA cm-2, amaani g‘obutafaari 1.76 V, FE 82%), esente zoona ezirikukoresibwa n‘ezirikuruga omu nkora ni US$2429 na US$2564, buri kimwe, ekirikuhindura amagoba g‘omugasho ga US$135 ahari buri tani ya Susetepp9 erikukorwa).
a Omuhendo gwona ogw‘omuringo gw‘amashanyarazi gwa AA ahansi y‘enkora y‘okubanza n‘oburemeezi bw‘amashanyarazi bwa 82%, oburemeezi bw‘amashanyarazi bwa 300 mA cm−2, n‘oburemeezi bw‘amashanyarazi bwa 1.76 V. Okushwijuma okuhurira kw‘omuhendo gw‘amashanyarazi ahari b FE na c oburemeezi bw‘amashanyarazi. Omu kucondooza kw‘okuhurira, ebipimo ebyashomwa byonka nibyo byahindurwa kandi ebindi bipimo bikaguma biri nk‘oku biri kurugiirira aha nkora ya TEA. d Ebirugire omu FE zitari zimwe na zimwe n‘obuhango bw‘amashanyarazi aha magoba g‘okukora amashanyarazi ga AA n‘amagoba g‘okukoresa Ni(OH)2-NS na NiV-LDH-NS, turikuteekateeka ngu amashanyarazi g‘obutafaari nigaguma gatarikuhinduka ahari 1.76 V. Ebihandiiko by‘okutaho ebya a–d nibiheebwa omu fairo y‘ebihandiiko ebitahikire.
Okurugirira aha nteekateeka egi, tukagaruka twacondooza aha nkora ya FE n‘obuhango bw‘obwire obu aha kutunga sente z‘okukora amashanyarazi ga AA. Twashanga ngu okutunga sente nikukwatwaho munonga FE ya AA, ahabw‘okuba okukyendeera kwa FE nikureetaho okweyongyera kw‘amaani omu sente z‘okukora, obwo nikwo kwongyera munonga aha sente zoona (ekishushani 7b). Aha bikwatiraine n‘oburemeezi bw‘amashanyarazi, oburemeezi bw‘amashanyarazi oburi ahaiguru (>200 mA cm-2) nibuhwera kukyendeeza aha sente z‘okutandikaho n‘esente z‘okwombeka ebyombeko, okukira munonga ahabw‘okukyendeeza aha mwanya gw‘obutafaari bw‘amashanyarazi, obwo nikihwera omu kweyongyera kw‘amagoba (ekishushani 7c). Waagyeragyeranisa n‘obuhango oburiho hati, FE eine akakwate kakuru n‘amagoba. Omu kushoboorora oku FE n‘oburemeezi bw‘amashanyarazi birikukwata aha magoba, nitureeba gye obukuru bw‘okutunga FE y‘ahaiguru (>60%) aha buhango bw‘amashanyarazi oburikukwata aha by‘amakorero (>200 mA cm-2) kureeba ngu amagoba gatunga. Ahabw‘omuhendo gwa FE gw‘ahaiguru ogwa AA, enkora y‘okugarukamu erimu NiV-LDH-NS nk‘ekirikureetaho okuhinduka neeguma eri nungi omu nkora ya 100–500 mA cm−2 (obutonyezi bwa pentagram; ekishushani 7d). Kwonka, ahari Ni(OH)2-NS, okukyendeeza FE aha nkora y‘amaani maingi (>200 mA cm−2) kikareetera ebyarugamu ebitari birungi (enzindo; ekishushani 7d), ekirikworeka obukuru bw‘ebikwato ebirikureetaho FE nyingi aha nkora y‘amaani maingi.
Okwongyera aha bukuru bw‘ebintu ebirikureetaho okukyendeeza aha sente z‘okutandikaho n‘okukora, okucondooza kwaitu okwa TEA nikworeka ngu okutunga sente nikubaasa kwongyera kutunguuka omu miringo ebiri. Eky’okubanza n’okuguza hamwe potassium sulfate (K2SO4) aha katare nk’ekintu ekirikuruga omu kicweka ky’okukyendeeza obutwa, kwonka n’okubaasa kutunga sente zirikwingana US$828/t AA-1 (Ekihandiiko ky’okwongyeraho 9). Ekyakabiri n‘okutunguura tekinologiya y‘okukora, obariiremu okugaruza ebintu omu nkora nari okukora tekinologiya z‘okwahukana za AA ezitarikutwara sente nyingi (emiringo endiijo y‘okukoresa ebicweka by‘okutaho obutafaari n‘okwahukana). Enkora y‘okukyendeeza asidi-base erikukoresibwa hati neebaasa kurugamu esente nyingi z‘ebintu (ezirikutwara omugabo muhango ahari 85.3%), aharizo 94% niziruga omu cyclohexanone na KOH ($2069/t AA-1; ekishushani 7a), kwonka nk‘oku kyagambirweho ahaiguru, enkora egi neeguma neereeta amagoba omu bwijwire. Nituteekateeka ngu esente z‘ebintu nizibaasa kwongyera kukyendeezibwa ahabw‘emiringo y‘omurembe ey‘okugaruzaho KOH na cyclohexanone etaine nkora, nk‘okukoresa amashanyarazi g‘okugaruzaho KOH14 omu bwijwire (omuhendo ogurikuteberezibwa kuba US$1073/t AA-1 kurabira omu kukozesa amashanyarazi; Ekihandiiko ky‘okwongyeraho 9).
Omu bugufu, tukatunga oburungi bw’ahaiguru obw’okukoresa amashanyarazi g’atomu ya aluminiyamu aha nkora y’amaani maingi turikuta V omu Ni(OH)2 nanosheets. Ahansi y‘obushoboorozi bwingi bwa 1.5–1.9 VRHE n‘oburemeezi bw‘amaani bw‘amaani bwa 170 mA cm−2, AA FE aha NiV-LDH-NS ekahika ahari 83–88%, obwo OER erikuzibirwa gye kuhika ahari 3%. Okuhindura kwa V kukatunguura okukyendeeza kwa Ni2+ kuhika ahari Ni3+x kandi kwatunguura okushohoza kwa cyclohexanone. Ebihandiiko by‘okugyezesa n‘eby‘okuteekateeka nibyoreka ngu okugaruka kwombeka okurikusiimura nikwongera oburemeezi bw‘obwire obu ahabw‘okuhindura cyclohexanone oxidation kandi nikuhindura RDS ya COR kuruga omu kugaruka kwombeka kuza omu kusheeshasheesha okurikutwariramu Cα − H scission, obwo okugaruka kwombeka okurikwongyerwamu amaani kwa cyclohexanone kurikuzibira OER. Entunguuka ya MEA ekatunga okukora AA okutarikuhwaho aha nkora y’amakorero eya 300 mA cm−2, oburungi bwa AA obuhandiikirwe 82%, n’okukora 1536 μmol cm−2 h−1. Okukyebera kw‘eshaaha 50 kukooreka ngu NiV-LDH-NS eine okuhama kurungi nk‘oku erikubaasa kuguma eine AA FE y‘ahaiguru omu MEA (> 80% kumara eshaaha 60 ahari 200 mA cm−2; > 70% kumara eshaaha 58 ahari 300 mA cm−2). Nikimanyisa ngu hariho ekyetengo ky‘okukora AEM z‘amaani maingi kubaasa kutunga okutegyeka kw‘obwire buraingwa aha nkora z‘amashanyarazi ezihikire omu by‘amakorero. Okwongyera ahari ekyo, TEA neeyoreka oburungi bw‘eby‘entasya bw‘enkora z‘okugarukamu ahabw‘okukora AA n‘obukuru bw‘ebintu ebirikukora gye munonga n‘eby‘omurembe eby‘okwahukana kwongyera kukyendeeza aha sente.