Hydrangea-Like Cu ₂ O/Cu ₂ S/ZnS Decorated Cu Foam as Dual Heterojunction Photocatalysts for H ₂ Production

High Resolution Image Download MS PowerPoint Slide An immobilized photocatalyst with high H 2 production activity was prepared by loading a ternary heterostructure of Cu 2 O/Cu 2 S/ZnS on the copper foam (CF) substrate. Heterojunction engineering is essential for photocatalysis. By tuning the oxidation conditions, a hydrangea-like high-surface-area Cu 2 O framework, composed of curved nanosheets with a thickness of 100–180 nm, forms on Cu foam. Subsequent controlled sulfidation (ion exchange) and successive ionic layer adsorption and reaction (SILAR) deposition yield conformal Cu 2 O/Cu 2 S/ZnS domains that form intimate heterojunction interfaces throughout the 3D conductive scaffold. Effects of experimental parameters on morphological evolution and H 2 production are studied. The sulfidation conditions and the number of SILAR cycles were varied to optimize the loading of Cu 2 S and ZnS. PL and photocurrent responses indicate improved charge transfer in the immobilized ternary photocatalyst. Band structure analysis suggests that photogenerated holes migrate toward the valence band of Cu 2 S, and electrons accumulate in the conduction band of ZnS and Cu 2 O. The optimal CF/Cu 2 O/Cu 2 S/ZnS photocatalyst exhibits a high H 2 production activity of 100.3 μmol cm –2 h –1 (apparent quantum yield (AQY) = 1.04%), and retains 83.7% of its activity after 5 cycles.