Electrochemical and Dip‐Coating Synthesis of Dendritic Cu/CuI Nanowire Films and Their Application in Dye Degradation Under UV Irradiation

Films of dendritic Cu/CuI nanowires were prepared on indium‐doped tin oxide substrates through the electrochemical deposition of Cu nanowires followed by the layer formation of CuI on the nanowires by a dip‐coating technique. The morphology and crystallinity of the dendritic Cu nanowires and Cu/CuI nanowires were characterized by field‐emission scanning electron microscopy and X‐ray diffraction. The photocatalysis of the Cu/CuI nanowires was monitored by the degradation of methylene blue in aqueous solution under UV‐light irradiation (λ ≈ 365 nm). The as‐prepared Cu/CuI nanowires exhibited a photocatalytic activity 5.3 times greater than that of a simple CuI film, and the photocatalytic activity showed a bell‐shaped dependence on the dip‐coating time. The enhanced photocatalytic activity of the Cu/CuI nanowires was attributed to their high adsorption capacity and enhanced electron transport. These results are useful for designing metal/semiconductor nanocomposites for high‐efficiency photocatalytic applications.