Hierarchical Z Scheme g-C3N4/Au/ZnIn2S4 Photocatalyst for Highly Enhanced Visible-Light Photocatalytic Nitric Oxide Removal and Carbon Dioxide Conversion
We successfully prepared a ternary Z-scheme photocatalyst, g-C3N4/Au/ZnIn2S4 (CN/Au/ZIS), for visible-light-driven NO removal and CO2 reduction by selecting Au NPs as the electron transfer mediator. The prepared photocatalysts demonstrated enhanced light absorption and a high surface area, which significantly improved the photocatalytic efficiency. The optimized CN/Au/ZIS photocatalyst achieved the highest NO removal efficiency of 59.7% and an excellent CO production rate of 242.3 μmol h−1 g−1 with a high selectivity of 94.1%, which were higher than those for pure g-C3N4 and ZnIn2S4. The improved photocatalytic activity could be ascribed to the Au NPs, which acted as an electron transfer mediator and enhanced the separation efficiency of the photogenerated electron–hole pairs. Additionally, the Z-scheme heterostructure affords the photocatalysts with a strong redox ability during the catalytic process. Finally, a possible Z-scheme mechanism for the CN/Au/ZIS photocatalytic system is detailed. This work sheds light on the design of high performance Z-scheme photocatalysts to advance photocatalytic redox capability.