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

Photocatalytic conversion of low-concentration CO 2 with H 2 O 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 CO 2 conversion. Herein, a highly-crystalline Ag x Na 1−x TaO 3 -AgCl heterostructure composite was successfully fabricated via a one-step flux method. The in-situ formation of intimate heterojunction between Ag x Na 1−x TaO 3 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 CO 2 on the photocatalyst surface. When combined with metallic Ag cocatalysts, the Ag x Na 1−x TaO 3 -AgCl heterostructure photocatalyst exhibited an improved activity for the overall reaction of CO 2 reduction and H 2 O oxidation at low CO 2 concentration condition. The design of photocatalysts active at low CO 2 concentration accounts for an alternative way to construct the practical CO 2 conversion system in the future.