Effect of impurity in Cu2O nanowires on the degradation of methyl orange

Effect of the impurity in Cu₂O nanowire on the degradation of methyl orange under light irradiation in dark circumstances was investigated. Here, we present the fabrication of Cu₂O nanowires at different temperatures (110, 130, 150, 170, and 190 °C) by a facile hydrothermal route. Meanwhile, at the synthesis temperature of 110–150 °C, the major impurity in Cu₂O nanowires was Cu₄O₃, and a new Cu impurity was introduced in the Cu₂O nanowires as the synthesis temperature increased from 170 to 190 °C. Overall, as the synthesis temperature increases from 110 to 190 °C, the total impurity decreases in Cu₂O nanowires. The fast degradation rate in dark circumstances has been achieved in Cu₂O nanowires for all synthesis temperatures, which can be attributed to the Cu²⁺ in the Cu₄O₃ impurity of Cu₂O nanowires. This result shows that the Cu₂O nanowires obtained at the synthesis temperature of 150 °C have the fastest degradation rate for both under light irradiation and in dark circumstances. It has been found that under light irradiation, the Cu impurity in Cu₂O nanowires plays a vital role in the degradation of methyl orange. In the current scenario, different impurity contents influence the catalyst activity of Cu₂O nanowires under the visible light or dark, respectively.