Photocatalytic activity of CuO and Cu2O nanowires

Here we report the photocatalytic efficiency of CuO and Cu2O nanowires studied by dye degradation in water. The CuO nanowires were synthesized on Cu foils by thermal oxidation. A subsequent thermal annealing induced a controllable phase transformation of the nanowires and the underlying film from CuO to Cu2O phase. A structural characterization was made by scanning and transmission electron microscopies, energy dispersive x-ray analysis and x-ray diffraction. The photocatalytic performances were evaluated by the degradation of two dyes in water: methylene blue and methyl orange. In particular, CuO nanowires showed a good photocatalytic activity in degrading methyl orange, compared with Cu2O nanowires. The photocatalytic activity was correlated to the physical-chemical properties of the samples, revealing the detrimental effect of the polycrystalline structure for photocatalytic process.