Efficient photocatalytic carbon dioxide conversion by 3-dimensional structured Z-scheme photocatalyst

Abstract

In this work, we significantly enhanced photocatalytic $CO_2$ conversion activity of $Cu_2O$ by constructing Z-scheme charge flow through hybridization of $Cu_2O$ with 3-dimensional nanowire arrays (NWAs) and $BiVO_4$. The BVO/C/$Cu_2O$ photocatalyst showed significantly enhanced charge separation and light harvesting properties, which result in 9.4 times and 4.7 times higher CO formation rate than those of $Cu_2O$ mesh and $Cu_2O$ NWAs under visible light irradiation. Coumarin probe molecule photoluminescence experimental result verifies that such enhancement was due to Z-scheme charge transfer mechanism that is photo-induced electron flow from conduction band of $BiVO_4$ to valence band of $Cu_2O$ via conductive carbon. In addition, our catalyst retained 98 % of initial photocatalytic $CO_2$ conversion performance after 5 reaction cycles (20 h) due to prevention of self-oxidation of $Cu_2O$ by protective carbon layer and z-schematic charge flow.