Iindaba – Ukukhula kwemfuno yamafutha asekelwe kwikhabhoni ukuze axhase uqoqosho kuyaqhubeka nokwandisa ubungakanani bekhabhoni diokside (CO2) emoyeni. Ngelixa kusenziwa imizamo yokunciphisa ukukhutshwa kwe-CO2, oku akunciphisi iziphumo eziyingozi zegesi esele ikwimo-moya. Ngoko ke abaphandi baye bavela neendlela zobuchule zokusebenzisa i-CO2 esemoyeni ngokuyiguqula ibe zizinto ezixabisekileyo ezifana ne-formic acid (HCOOH) kunye ne-methanol. Ukunciphisa i-CO2 ngefoto kusetyenziswa ii-photocatalysts kusetyenziswa ukukhanya okubonakalayo njenge-catalyst yindlela ethandwayo yokuguqulwa okunjalo.
Kwimpumelelo yamva nje, etyhilwe kwi-Angewandte Chemie yamazwe ngamazwe nge-8 kaMeyi 2023, uNjingalwazi uKazuhiko Maeda kunye neqela lakhe lophando kwiTokyo Institute of Technology benze inkqubela phambili ebalulekileyo. Baphumelele ekuphuhliseni i-tin (Sn) metal-organic framework (MOF) ekhuthaza ukususwa kwe-CO2 ngokukhetha. I-MOF esandul’ ukwaziswa yabizwa ngokuba yi-KGF-10 kwaye ifomula yayo yekhemikhali yi-[SnII2(H3ttc)2.MeOH]n (H3ttc: trithiocyanuric acid, MeOH: methanol). Ngokusebenzisa ukukhanya okubonakalayo, i-KGF-10 iguqula i-CO2 ibe yi-formic acid (HCOOH). UNjingalwazi uMaeda ucacisile, “Ukuza kuthi ga ngoku, kuye kwaphuhliswa ii-photocatalysts ezininzi ezisebenzayo zokunciphisa i-CO2 ngokusekelwe kwiintsimbi ezinqabileyo nezibalaseleyo. Nangona kunjalo, ukudibanisa imisebenzi yokufunxa ukukhanya kunye ne-catalytic kwiyunithi enye yeemolekyuli eyenziwe linani elikhulu leentsimbi kusengumngeni.” Ngoko ke, uSn ubonakalise ukuba umviwa ofanelekileyo wokoyisa le miqobo mibini.”
Ii-MOF, ezidibanisa iingenelo zeentsimbi kunye nezinto eziphilayo, zijongwa njengendlela eluhlaza ngakumbi kunee-photocatalysts zemveli ezisekelwe kwiintsimbi ezinqabileyo zomhlaba. I-Sn, eyaziwa ngendima yayo ephindwe kabini njenge-catalyst kunye ne-light absorber kwiinkqubo ze-photocatalyst, inokuba lukhetho olufanelekileyo kwii-photocatalysts ezisekelwe kwi-MOF. Nangona ii-MOF ezenziwe yi-zirconium, isinyithi, kunye ne-lead zifundwe ngokubanzi, ukuqonda ii-MOF ezisekelwe kwi-Sn kusancinci. Izifundo ezongezelelweyo kunye nezifundo ziyafuneka ukuze kuhlolwe ngokupheleleyo amathuba kunye nokusetyenziswa okunokwenzeka kwee-MOF ezisekelwe kwi-Sn kwicandelo le-photocatalysis.
Ukuze kwenziwe i-MOF KGF-10 esekelwe kwi-tin, abaphandi basebenzise i-H3ttc (i-trithiocyanuric acid), i-MeOH (i-methanol), kunye ne-tin chloride njengezinto zokuqala. Bakhethe i-1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]imidazole njengomnikeli we-electron kunye nomthombo we-hydrogen. Emva kokwenziwa, i-KGF-10 efunyenweyo yafakwa kwiindlela ezahlukeneyo zohlalutyo. Ezi mvavanyo zibonise ukuba izinto zinamandla okutsalwa kwe-CO2 aphakathi kunye ne-band gap ye-2.5 eV kunye nokufunxwa okusebenzayo kuluhlu lwamaza olubonakalayo.
Bexhobe ngolwazi lweempawu zomzimba nezekhemikhali zezinto ezintsha, oososayensi bazisebenzisele ukunyusa ukuncipha kwekhabhoni diokside ngokukhanya okubonakalayo. Okuphawulekayo kukuba, abaphandi bafumanise ukuba i-KGF-10 ifikelela kuguquko lwe-CO2 ukwenza i-(HCOO-) ngokukhetha ukuya kuthi ga kwi-99% ngaphandle kwe-photosensitizer okanye i-catalyst encedisayo. Ukongeza, i-KGF-10 ibonise isivuno se-quantum esiphezulu esingabonakaliyo - umlinganiselo wokusebenza kakuhle kokusebenzisa ii-photons - ukufikelela kwixabiso le-9.8% kwi-400 nm. Okuphawulekayo kukuba, uhlalutyo lwesakhiwo olwenziwe ngexesha le-photocatalytic reaction lubonise ukuba i-KGF-10 idlula kutshintsho lwesakhiwo ukunceda kwinkqubo yokunciphisa.
Olu phando lubalaseleyo lubonisa i-photocatalyst esebenza kakuhle kakhulu esekelwe kwi-tin KGF-10 engenasidingo seentsimbi ezintle njengesixhobo sokunciphisa i-CO2 ukuze ibumbeke ngokukhanya okubonakalayo. Iimpawu ezimangalisayo ze-KGF-10 eziboniswe kolu phononongo zinokuguqula ukusetyenziswa kwayo njenge-photocatalyst kwizicelo ezahlukeneyo, kubandakanya nokunciphisa i-CO2 yelanga. UNjingalwazi Maeda ugqiba ngelithi: “Iziphumo zethu zibonisa ukuba ii-MOF zinokusebenza njengeqonga lokuphuhlisa amandla aphezulu e-photocatalytic ngokusebenzisa iintsimbi ezingenabungozi, ezingabizi kakhulu, nezininzi ezifumaneka eMhlabeni, ezidla ngokuba zii-molecule metal complexes. Ayifumaneki.” Olu phando luvula amathuba amatsha. Amathuba okufumana ulwazi kwicandelo le-photocatalysis kwaye luvula indlela yokusetyenziswa okuzinzileyo nokufanelekileyo kwezixhobo zoMhlaba.
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