Effect of annealing temperature on the surface properties and photocatalytic efficiencies of Cu₂O/CuO structures obtained by thermal oxidation of Cu layer on titanium substrates

In the present study, cuprous oxide (Cu₂O)and cupric oxide (CuO) structures were prepared by thermal oxidation of electroplated copper (Cu) coatings on titanium substrates. The influence of different annealing temperatures from 200 to 600 °C on the morphology, crystal structure and the photocatalytic activity of the Cu₂O and CuO structures were studied in detail. The photocatalysts were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Photocatalytic activities of the samples were examined by the degradation of methylene blue (MB) under UV light irradiation. The spectroscopic analysis was investigated by UV–vis spectrophotometer. The results showed that the microstructure and surface morphology of the samples changed considerably at different annealing temperatures. The sample annealed at 500 °C exhibited the highest photocatalytic activity. The results indicated that need-like surface morphology and phase structure play an important role in enhancement the photocatalytic performance of Cu₂O/CuO structures.