Oxygen Vacancy and Metallic Silver Site Coinjection Associates Photocatalytic CO2 Reduction upon Mesoporous NH2-TiO2 Nanoparticles Assembly

Solar-driven CO2 conversion is a promising approach to tackle the issues of increasing greenhouse gases and energy shortage. Herein, a defective amine silver species-modified mesoporous TiO2 (NH2-TiO2-x-Ag) nanoparticle assembly for photocatalytic CO2 reduction is reported. In particular, simultaneous oxygen vacancy incorporation and silver species anchoring in the formation of NH2-TiO2 derived from amine-modified protonated titanate during polyol-mediated solvothermal treatment are achieved. Indeed, the NH2-TiO2-x-Ag with different amounts of Ag species can enhance photocatalytic CO2 reduction into CH4 and CO. The NH2-TiO2-(x)-Ag-0.05 sample has the highest CH4 and CO yields with rates of 6.11 and 0.91 mu mol g(-1) h(-1), respectively, which are about 10.7 and 7 times higher than that of pristine NH2-TiO2. These findings demonstrate that the synergic impact of oxygen vacancies and metallic silver sites embedded into NH2-TiO2 can prevent poor light harvesting, fast recombination of photogenerated electrons and holes, and inadequate surface-active sites.

Automated summary

In this study, a defective amine silver species-modified mesoporous TiO2 nanoparticle assembly was reported for photocatalytic CO2 reduction. The results showed that this material can enhance the photocatalytic conversion of CO2 into CH4 and CO.