Ultrafine Cu2O/CuO nanosheet arrays integrated with NPC/BMG composite rod for photocatalytic degradation

A free-standing Cu₂O/CuO@nanoporous copper/bulk metallic glass (Cu₂O/CuO@NPC/BMG) composite rod with a multimodal hierarchical porous structure has been successfully prepared by a facile two-step synthesis strategy consisting of dealloying and anodizing. The NPC/BMG composite is first fabricated by dealloying of Cu₅₀Zr₄₅Al₅ BMG rod. Then the ultrafine Cu₂O/CuO nanosheet arrays are synthesized by anodizing of the NPC/BMG rod followed by heat treatment. The as-obtained Cu₂O/CuO@NPC/BMG composite possesses a multimodal hierarchical porous structure comprising interconnected pores ranging from micro, meso to macro sizes. It is worth pointing out that there are several "barren lands" without nanosheets grown on the surface of the composite. Further analyses indicate that the microstructures of substrate materials not only dominate the sizes of Cu₂O/CuO sheets, but also influence the nucleation and growth of Cu₂O/CuO sheets. Meanwhile, the possible formation mechanism of the Cu₂O/CuO nanosheets is proposed. Accordingly, the Cu₂O/CuO@NPC/BMG composite shows remarkably high photocatalytic degradation performance and excellent cycling stability for RhB due to the multimodal hierarchical porous structure, ultrafine Cu₂O/CuO nanosheets in the entire NPC and the integration design strategy.