Low-concentration CO2 conversion on AgxNa1−xTaO3-AgCl heterojunction photocatalyst

Photocatalytic conversion of low-concentration CO2 with H2O oxidation indicates an applicable way to achieve sustainable carbon cycling and solve the global warming problem. Enhancing photogenerated charge separation and surface adsorption and catalytic process of photocatalysts is the crucial point to compensate for the mass transfer limitation during low-concentration CO2 conversion. Herein, a highly-crystalline AgxNa1−xTaO3-AgCl heterostructure composite was successfully fabricated via a one-step flux method. The in-situ formation of intimate heterojunction between AgxNa1−xTaO3 and AgCl facilitated the separation and transfer of photogenerated charges. Moreover, the simultaneous introduction of Ag cations and AgCl components promoted the adsorption and activation of CO2 on the photocatalyst surface. When combined with metallic Ag cocatalysts, the AgxNa1−xTaO3-AgCl heterostructure photocatalyst exhibited an improved activity for the overall reaction of CO2 reduction and H2O oxidation at low CO2 concentration condition. The design of photocatalysts active at low CO2 concentration accounts for an alternative way to construct the practical CO2 conversion system in the future.