Iminerali yomhlabathi esakazeke kabanzi, i-α-iron-(III) oxyhydroxide, itholakale iyisisusa esingaphinde sisetshenziswe sokunciphisa i-carbon dioxide ibe yi-formic acid. Isikweletu: UProfesa Kazuhiko Maeda
Ukunciphisa i-CO2 ibe yi-photoreduction ibe yi-fuel ethwalwayo njenge-formic acid (HCOOH) kuyindlela enhle yokulwa namazinga e-CO2 akhuphukayo emoyeni. Ukuze kusizwe ngalo msebenzi, ithimba labacwaningi eTokyo Institute of Technology likhethe i-mineral esekelwe ensimbini etholakala kalula futhi layilayisha ekusekelweni kwe-alumina ukuze kuthuthukiswe i-catalyst engashintsha i-CO2 ibe yi-HCOOH ngempumelelo, cishe ukukhetha okungu-90%!
Izimoto zikagesi ziyindlela ekhangayo kubantu abaningi, futhi isizathu esiyinhloko ukuthi azinawo ukukhishwa kwekhabhoni. Nokho, inkinga enkulu kwabaningi ukuntuleka kwazo kwebanga kanye nezikhathi zokushaja ezinde. Yilapho uphethiloli oketshezi njengophethiloli unenzuzo enkulu khona. Ubuningi bamandla azo busho ukuhamba ibanga elide kanye nokugcwalisa uphethiloli ngokushesha.
Ukushintsha kusuka kuphethiloli noma udizili uye kolunye uphethiloli oluwuketshezi kungasusa ukukhishwa kwekhabhoni ngenkathi kugcinwa izinzuzo zamafutha oluketshezi. Kuseli likaphethiloli, isibonelo, i-formic acid inganika amandla injini ngenkathi ikhipha amanzi kanye ne-carbon dioxide. Kodwa-ke, uma i-formic acid ikhiqizwa ngokunciphisa i-CO2 yomoya ibe yi-HCOOH, khona-ke okuwukuphela kokukhipha okunetha ngamanzi.
Ukwenyuka kwamazinga e-carbon dioxide emoyeni wethu kanye negalelo lawo ekufudumaleni komhlaba manje sekuyizindaba ezivamile. Njengoba abacwaningi bezama izindlela ezahlukene zokuxazulula le nkinga, kwavela ikhambi eliphumelelayo—ukuguqula i-carbon dioxide eningi emoyeni ibe amakhemikhali acebile ngamandla.
Ukukhiqizwa kwamafutha afana ne-formic acid (HCOOH) ngokunciphisa ukukhanya kwelanga kudonsele ukunaka okukhulu muva nje ngoba le nqubo inenzuzo ephindwe kabili: inciphisa ukukhishwa kwe-CO2 okweqile futhi isiza ekunciphiseni ukushoda kwamandla esibhekene nawo njengamanje. Njengesithwali esihle kakhulu se-hydrogen esinobuningi bamandla aphezulu, i-HCOOH inganikeza amandla ngokushisa ngenkathi ikhipha amanzi kuphela njengomkhiqizo olandelanayo.
Ukuze benze lesi sixazululo esizuzisayo sibe ngokoqobo, ososayensi bathuthukise izinhlelo ze-photocatalytic ezinciphisa i-carbon dioxide ngosizo lokukhanya kwelanga. Lolu hlelo luqukethe i-substrate emunca ukukhanya (okungukuthi, i-photosensitizer) kanye ne-catalyst evumela ukudluliselwa kwama-electron amaningi okudingekayo ukuze kuncishiswe i-CO2 ibe yi-HCOOH. Ngakho-ke baqala ukufuna ama-catalyst afanele futhi asebenzayo!
Ukunciphisa i-carbon dioxide nge-photocatalytic kusetshenziswa i-infographics evame ukusetshenziswa. Isikweletu: UProfesa Kazuhiko Maeda
Ngenxa yokusebenza kahle kwazo kanye nokusebenziseka kabusha okungenzeka, ama-catalyst aqinile abhekwa njengabafanelekela lo msebenzi, futhi eminyakeni edlule, amakhono okukhulisa i-cobalt, manganese, nickel kanye nezinhlaka zensimbi-organic (MOFs) eziningi ezisekelwe ku-iron (ama-MOF) aye ahlolwa, phakathi kwawo lawa anenzuzo ethile kunezinye izinsimbi. Kodwa-ke, ama-catalyst amaningi asekelwe ku-iron abikwe kuze kube manje akhiqiza i-carbon monoxide njengomkhiqizo oyinhloko, hhayi i-HCOOH.
Kodwa-ke, le nkinga yaxazululwa ngokushesha yithimba labacwaningi eTokyo Institute of Technology (Tokyo Tech) eliholwa nguSolwazi Kazuhiko Maeda. Ocwaningweni lwamuva nje olushicilelwe kumagazini wamakhemikhali i-Angewandte Chemie, iqembu libonise i-catalyst esekelwe ku-alumina (Al2O3) esebenzisa i-α-iron(III) oxyhydroxide (α-FeO​​​ OH; geothite). I-catalyst entsha ye-α-FeO​​OH/Al2O3 ibonisa ukusebenza okuhle kakhulu kokuguqulwa kwe-CO2 kuya ku-HCOOH kanye nokusetshenziswa kabusha okuhle kakhulu. Lapho ebuzwa ngokukhetha kwabo i-catalyst, uSolwazi Maeda uthe: “Sifuna ukuhlola izakhi eziningi kakhulu njenge-catalysts ezinhlelweni zokunciphisa i-CO2. Sidinga i-catalyst eqinile esebenzayo, ephinde isetshenziswe, engenabo ubuthi futhi engabizi. Yingakho sikhethe amaminerali enhlabathi asatshalaliswa kabanzi njenge-goethite ekuhlolweni kwethu.”
Ithimba lisebenzise indlela elula yokufakelwa ukuze lenze i-catalyst yabo. Base besebenzisa izinto ze-Al2O3 ezisekelwa yinsimbi ukuze banciphise i-CO2 ngokukhanya kwe-photocatalytic endaweni yokushisa kwegumbi lapho kukhona i-photosensitizer esekelwe ku-ruthenium (Ru), i-electron donor, kanye nokukhanya okubonakalayo okunama-wavelength angaphezu kwama-nanometer angu-400.
Imiphumela iyakhuthaza kakhulu. Ukukhethwa kohlelo lwabo lomkhiqizo oyinhloko i-HCOOH kwakungu-80–90% kanye nesivuno se-quantum esingu-4.3% (okubonisa ukusebenza kahle kohlelo).
Lolu cwaningo luveza i-catalyst eqinile esekelwe ensimbini yokuqala yohlobo lwayo engakhiqiza i-HCOOH uma ihlanganiswe ne-photosensitizer ephumelelayo. Luphinde luxoxe ngokubaluleka kwezinto zokusekela ezifanele (i-Al2O3) kanye nomthelela wayo ekusabeleni kokunciphisa i-photochemical.
Ukuqonda okuvela kulolu cwaningo kungasiza ekuthuthukiseni ama-catalyst amasha angenansimbi angcono okunciphisa i-carbon dioxide kwamanye amakhemikhali awusizo. "Ucwaningo lwethu lubonisa ukuthi indlela eya emnothweni wamandla aluhlaza ayinzima. Ngisho nezindlela ezilula zokulungiselela ama-catalyst zingaletha imiphumela emihle, futhi kwaziwa kahle ukuthi ama-compounds amaningi emhlabeni, uma esekelwa ama-compounds afana ne-alumina, angasetshenziswa njenge-catalyst ekhethiwe yokunciphisa i-CO2," kuphetha uSolwazi Maeda.
Izikhombo: "I-Alumina-Supported Alpha-Iron (III) Oxyhydroxide njenge-Recyclable Solid Catalyst ye-CO2 Photoreduction ngaphansi kokukhanya Okubonakalayo" ngu-Daehyeon An, uDkt. Shunta Nishioka, uDkt. Shuhei Yasuda, uDkt. Tomoki Kanazawa, uDkt. Yoshinobu Kamakura, Prof. Yoshinobu Kamakura, Prof. Kazuhiko Maeda, 12 May 2022, Angewandte Chemie.DOI: 10.1002 / anie.202204948
"Yilapho uphethiloli owuketshezi njengophethiloli unenzuzo enkulu khona. Ubuningi bawo bamandla busho ukuhamba ibanga elide kanye nokugcwalisa uphethiloli ngokushesha."
Kuthiwani ngezinye izinombolo? Ubuningi bamandla e-formic acid buqhathaniswa kanjani nophethiloli? Njengoba kune-athomu eyodwa yekhabhoni kufomula yamakhemikhali, angingabazi ukuthi ingasondela ngisho nakuphethiloli.
Ngaphezu kwalokho, iphunga linobuthi kakhulu futhi, njenge-asidi, liyagqwala kakhulu kunephethiloli. Lezi akuzona izinkinga zobunjiniyela ezingaxazululeki, kodwa ngaphandle kokuthi i-formic acid inikeza izinzuzo ezibalulekile ekwandiseni ububanzi kanye nokunciphisa isikhathi sokugcwalisa ibhethri, cishe akufanele umzamo.
Uma behlela ukukhipha i-goethite enhlabathini, bekuyoba umsebenzi wokumba odinga amandla amaningi futhi okungenzeka ukuthi ulimaza imvelo.
Bangase bakhulume nge-goethite eningi enhlabathini njengoba ngicabanga ukuthi kuzodinga amandla engeziwe ukuthola izinto zokusetshenziswa ezidingekayo bese zisabela ekuhlanganiseni i-goethite.
Kuyadingeka ukubheka yonke imjikelezo yempilo yenqubo bese kubalwa izindleko zamandla zayo yonke into. I-NASA ayitholanga into efana nokuqaliswa kwamahhala. Abanye kudingeka bakukhumbule lokhu.
I-SciTechDaily: Ikhaya lezindaba zobuchwepheshe ezinhle kakhulu kusukela ngo-1998. Hlala usesikhathini ngezindaba zobuchwepheshe zakamuva nge-imeyili noma ezinkundleni zokuxhumana.
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