Characterization and performance of Cu₂O nanostructures on Cu wire photocatalyst synthesized in-situ by chemical and thermal oxidation

In this study, Cu₂O nanostructures on Cu wire were formed with in situ chemical and then thermal oxidation to obtain the desirable structure, morphology and optical properties in order to enhance visible-light photocatalytic activity. The findings suggested that the procedure involved solution phase treatment and formation of Cu₂O on pure Cu wire with two-step oxidation in controlled environment of nitrogen and air. Results showed that Cu₂O nanostructure on Cu substrate were formed from transformation of as-synthesized Cu(OH)₂ nanostructures. The kinetic studies for Cu(OH)₂ formation and the synthesis mechanism of Cu₂O nanostructures were investigated. The results show that the heterogeneous Cu/Cu₂O nanostructures display nanorod and polyhedral morphology. The MB degradation reaches 77–82% after 240 min visible light irradiation. The band gap values of the heat treated samples under nitrogen and air were obtained 1.75 and 2.00 eV, respectively. Intensity of PL spectra for the heat treated sample under nitrogen was obviously lower. Furthermore, it is observed that the first order and modified-Freundlich model fit the kinetic data well.