Selective Photocatalytic CO2 Reduction Through Plasmonic Z‐Scheme Ag‐Bi2O3‐ZnO Heterostructures

Abstract Combination of plasmonic noble metal with semiconductors offers a promising and potential solar energy harvesting and conversion route. Herein, plasmonic Z‐scheme Ag‐Bi 2 O 3 ‐ZnO (AgBZ) heterostructure is designed and synthesized via solution combustion and photo‐deposition method. Metallic Ag nanoparticles (NPs) were deposited over Bi 2 O 3 ‐ZnO heterostructure; thus, they exhibit strong visible light absorption owing to surface plasmon resonance (SPR). The photocatalytic efficiency of the synthesized catalysts is investigated by the photocatalytic CO 2 reduction to fuels under simulated solar light irradiation. The present system has shown an outstanding photocatalytic CO 2 reduction and excellent selectivity of CO. The evolved rate of CO fuel, the amount of CO produced per unit time, over optimized Ag‐Bi 2 O 3 ‐ZnO (3AgBZ) heterostructures was (96.74 μmol g −1 /h) which was approximately 12 times larger than that of Bi 2 O 3 ‐ZnO (0AgBZ) and 49‐fold than the quantity of evolved CO fuels over pure ZnO photocatalyst. The percentage of evolved CO to CH 4 fuels over optimized Ag‐Bi 2 O 3 ‐ZnO (3AgBZ) heterostructures was about 50 : 1compared to that of 2 : 3 over Bi 2 O 3 ‐ZnO (0AgBZ). The great improvement and the high selectivity would be ascribed to the synergistic effect of metallic surface plasmon resonance and the Z‐scheme charges transfer system. This work would open a window to construct a single photocatalyst with different charge separation systems and excellent CO 2 reduction selectivity. Finally, the mechanism for the enhanced photocatalytic performance by the synergistic effect was described and discussed.