Synchronistic embedding of oxygen vacancy and Ag nanoparticles into potholed TiO2 nanoparticles-assembly for collaboratively promoting photocatalytic CO2 reduction

Photocatalytic CO 2 reduction offers a potential to produce clean and renewable fuels as well as reduce massive emissions of CO 2 by utilizing solar energy. The inhibited charge recombination and fertile surface reactive sites play vital roles in determining the photocatalytic performance and products selectivity in CO 2 reduction reaction. Herein, the Ag/TiO 2-x hybrid by synchronistic introduction of oxygen vacancy and Ag nanoparticles into SiO 2 spheres-templated potholed TiO 2 assembly with nanoparticles is constructed for photocatalytic CO 2 conversion. The Schottky junction between oxygen vacancy TiO 2-x and Ag particles provides synergistic enhancement of solar light utilization, photo-induced charge separation and migration process, which is of significance in the promoted CO 2 photo-conversion. Indeed, the CH 4 yield of oxygen vacancy TiO 2-x (1.56 μmol/g/h) is more than 3 times as high as the TiO 2 (0.47 μmol/g/h), while the as-synthesized Ag/TiO 2-x hybrids show an enhancement of photocatalytic CO 2 reduction into CH 4 and CO. Among them, the Ag/TiO 2-x -10% hybrid has the best photocatalytic performance, and it shows significantly superior CH 4 (8.61 μmol/g/h) and CO (2.27 μmol/g/h) yields to that of pure TiO 2-x and TiO 2 .