Formation and evolution of ultrathin Cu2O nanowires on NPC ribbon by anodizing for photocatalytic degradation

Designing and synthesizing a new photocatalytic material with highly efficient organic pollutant degradation ability has been still a severe challenging subject. In this work, a ultrathin Cu2O nanowires@nanoporous copper (NPC) composite ribbon with multimodal hierarchical structure has been successfully prepared by dealloying an amorphous Cu50Zr45Al5 ribbon, followed by anodizing and then heat treatment. The diameter of the single Cu2O nanowire ranges from 4.5 to 11 nm and a large number of nanopores with small sizes of 2-3 nm are dispersed on each nanowire. The in-situ growth of Cu2O on the NPC substrate with increasing anodizing time results in a peculiar morphology evolution. The Cu2O gradually grows from the initial pen-like nanowire clusters to the flower-like nanowires. This work also provides the formation mechanism for the Cu2O nanowires through the understanding of the balance between thermodynamics and dynamics processes which is controlled by the applied current density. The new composite demonstrates ultrahigh photocatalytic property for RhB. The outstanding performance of the Cu2O@NPC composite is attributed to the synergy effect of large specific surface area (32.90 m(2)g(-1)), the low activation energy (27.2 kJ/mol) as well as the multimodal hierarchical porous structure. The mechanism on the RhB degeneration is also investigated.