검색 상세

Enhanced solar photoreduction of CO2 to liquid fuel over rGO grafted NiO-CeO2 heterostructure nanocomposite

초록/요약 도움말

Intrinsic oxygen vacancies at CeO2 surface are known to activate thermodynamically stable CO2 molecules, enhancing the reaction rate and reducing reduction energy. However, charge recombination at the ceria-based cathode surface suppresses the multi-electron transfer process required for a complete reduction of CO2 molecules to generate useful hydrocarbons. To suppress this charge recombination and facilitate the multi-electron transfer process, p-type NiO and reduced graphene oxide (rGO) were hybridized with CeO2 to form rGOgrafted NiO-CeO2 photocatalyst, which can convert CO2 to formaldehyde at a rate of 421.09 mu mol g (-1) h (-1); about 4 times higher than that of pristine CeO2. Formation of photo-induced oxygen vacancy of CeO2 photocatalyst resulted in a change of Ce-O bond length at ceria surface were monitored in-situ by X-ray absorption near edge structure (XANES), and X-ray absorption fine structure (EXAFS) spectroscopy. Tracking the formation of CO2 anion radical (CO2 center dot-) and its subsequent protonation with in-situ electron paramagnetic resonance spectroscopy and attenuated total reflection-infrared (ATR-IR) spectroscopy, mechanism and reaction pathway of CO2 reduction into formaldehyde formation have been elucidated.

more