Multi-functional CuO nanowire/TiO2 nanotube arrays photoelectrode synthesis, characterization, photocatalysis and SERS applications

•Single crystalline CuO nanowires were successfully immobilized on TiO2 nanotubes array.•Mass transport channel for Cu ions diffusion was confirmed.•Snow-like Ag nanocrystals modified CuO/TiO2 photoelectrodes exhibit superior catalytic and SERS properties.

Vertically aligned single crystalline CuO nanowire arrays (NWs) grown directly on TiO2 nanotube arrays (NTAs) supporting by Ti foil have been successfully fabricated using facile thermal oxidation of Cu nanocrystals in static air. CuO NWs growth behavior dependent on parent Cu nanocrystals sizes has been well investigated. Mass transport channel of Cu ions in horizontal and vertical for supporting CuO NWs diameter and length changes has been confirmed through a novel step-by-step surface diffusion process. CuO NWs, nano-mushrooms and nanosheets can be easily obtained by varying growth conditions. After photocatalytic synthesis of snow-like Ag nanocrystals upon CuO NWs/TiO2 NTAs, the hybrid photoelectrode exhibits superior catalytic property and detection sensitivity, which can clean themselves by photocatalytic degradation of RhB molecules adsorbed to the substrate under irradiation using surface enhanced Raman scattering (SERS) detection, a recycling can been achieved.

Graphical abstractThe growth process of CuO nanowires by thermal oxidation of deposition Cu nanocrystals on TiO2 NTAs in air.Figure optionsDownload full-size imageDownload as PowerPoint slide