Cube-in-Cube Hollow Cu9S5 Nanostructures with Enhanced Photocatalytic Activities in Solar H2 Evolution

Hydrogen produced from water under solar energy is an ideal clean energy source, and the efficiency of hydrogen production usually depends on the catalytic systems based on new compounds and/or a unique nanostructure. Herein, well-defined cube-in-cube hollow Cu9S5 nanostructures have been successfully prepared with Cu2O nanocubes and CS2 as precursors, and single-shell hollow Cu9S5 nanocubes could be obtained by replacing CS2 with Na2S. The formation mechanism of cube-in-cube hollow nanostructures has been proposed based on the Kirkendell effect and an outward self-assembly process. Further studies revealed that the cube-in-cube hollow Cu9S5 nanostructures exhibited better photocatalytic activity toward solar H-2 evolution and would be a promising photocatalyst in the solar hydrogen industry.