Oxygen vacancy-enrich Ag/brookite TiO2 Schottky junction for enhanced photocatalytic CO2 reduction

Abstract

Insufficient surface catalytic sites and charge kinetics constrains the progress of CO2 photoreduction reaction. In this work, oxygen vacancy-enriched Ag/brookite TiO2 hybrid by anchoring Ag nanoparticles on brookite TiO2 has been synthesized through the transformation of Ti-glycerol precursor with simultaneous reduction of Ag+ in the diethylene glycol (DEG)-H2O solution. In particular, the involving of oxygen vacancy and Ag species could extend light absorption range, facilitate charge separation and transfer, and accumulate the electrons on Ag center. As a result, the Ag/brookite TiO2 with formed Schottky junction reveals enhanced CO2 photoreduction performance compare with pristine TiO2 and solvothermal treated TiO2 (TiO2-sol). Particularly, the oxygen vacancy-enriched Ag/TiO2 hybrid shows the highest catalytic activity with CH4 and CO yields. This work offers an approach to modify brookite phase TiO2 with metallic sites and oxygen vacancy for improved CO2 photoreduction.