Morphological guidance and proportional control of Cu2O/ZnO core/shell heterojunction with enhanced visible-light-driven photocatalytic performance

As a candidate for photocatalyst, the photocatalytic performance of cuprous oxide (Cu2O) is severely restricted by its high charge carrier recombination rate, self-photocorrosion and the uncertainty of crystal plane. In order to improve the photocatalytic performance and deeply analyze the photocatalytic mechanism, the Cu2O nanocrystals with cubic, cuboctahedral and octahedral structures were combined with n-type ZnO to prepare Cu2O/ZnO heterojunction photocatalysts. The effects of crystal facet of Cu2O and Zn/Cu ratios on the photocatalytic performances of Cu2O/ZnO heterojunctions were explored into. The results show that the cuboctahedron Cu2O with {100} and {111} facets exhibits more surprising catalytic performance due to the energy-level difference between the two facets, leading to higher electron-hole pair separation efficiency when compared with the octahedral Cu2O with {111} facets and cubic Cu2O with {100} facets. In addition, optimized Cu2O/ZnO heterojunction with appropriate Zn/Cu ratio exhibits the collaborative advantages of the two materials, so the catalytic activity and stability are effectively improved.