Synergy between metal sites and oxygen vacancy for CO2 photoreduction: Activity and stability enhancement

ABS T R A C T In this work, TiO2 NPs (NPs) with abundant defects were successfully prepared as a substrate by photochemical method to load highly dispersed Pt NPs, focusing on the synergy between metal sites and oxygen vacancies for the enhancement of CO2 photoreduction performance and stability. As expected, H2-Pt/TiVo-UV exhibited excellent photocatalytic efficiency, with a photoreduction selectivity of up to 92.9 % for CO2 and a total electron yield of 382.4 mu mol g-1 h-1. More importantly, H2-Pt/TiVo-UV activity decreased by only 6.8 % after a continuous reaction of up to 24 h. TiO2 NPs with abundant defects promote the migration of photogenerated electrons. The highly dispersed Pt NPs acted as electron traps, promoting photogenerated carrier separation. Meanwhile, the synergy between metal sites and oxygen vacancies enhances the adsorption capacity to the reactants. The combined effect of these three factors provides the driving force for the improved photocatalytic performance. This work provides insight into the efficient use of noble metal catalysts.