Engineering of Hierarchical Z-scheme ZnSe/Fe2O3 Heterojunction Cubic Nanocages for Enhanced CO2 to CO Photoconversion

Abstract

The photocatalytic conversion of CO2 into fuels is a promising strategy for the achievement of global carbon neutrality. However, the weak redox reaction ability and fast charge recombination rate of a single component catalyst remain a huge bottleneck. To overcome these disadvantages, herein, hierarchical Z-scheme ZnSe/Fe2O3 heterojunction hollow cubic nanocages were designed and prepared involving Fe2O3 cubic nanocages (CNCs) derived through the straightforward thermal annealing of the FeOOH CNCs synthesized based on Pearson's principle using Cu2O as a sacrificial template and the following immobilization of ZnSe nanoparticles derived from the selenization of ZIF-8 nanolayer on the Fe2O3 CNCs. The experimental characterizations reveal that the Z-scheme ZnSe/Fe2O3 heterojunction cubic nanocage structure promotes efficient charge separation/transfer and preserves the reduction and oxidation abilities of the composites. These advantages make the optimized Z-scheme ZnSe/Fe2O3 CNC composite exhibits an excellent CO2 photoreduction performance compared to the pristine ZnSe with a CO yield of 30.8 µmol g-1 h-1. This work provides a new perspective on constructing photocatalyst systems with Z-scheme heterojunctions to enhance photocatalytic performance.