Preparation of Novel ZnO/Cu2O Heterojunctions Composite Film by Codeposition Method and Their Enhanced Photocatalytic Performance Analysis

Refractory organic pollutants have caused widespread concern about their pollution of water environments. Photocatalytic oxidation technology is an effective way to remove organic pollutants. Photocatalyst is the components core of photocatalytic oxidation technology. The development of visible light responsive catalysts with high catalytic activity is of great significance for the removal of organic pollutants using sunlight as a light source. In this paper, a codeposition method is used to prepare ZnO/Cu2O composite film with a heterojunction structure in one step. The microstructure and photoelectric properties of the prepared ZnO/Cu2O composite film are characterized and analyzed, and its photocatalytic performance is evaluated. Compared with pure the Cu2O film, the composite film exposes more (111) crystal planes, and has a smaller impedance and a larger photocurrent and open circuit voltage value. These findings indicate that the ZnO/Cu2O composite film exhibits excellent photogenerated carrier separation and migration efficiencies. Among the prepared samples, M-2 demonstrates the highest photocatalytic and recycling performance. The calculation of the band position shows that the Fermi level of the composite film exhibits a significant shift compared to that of the pure Cu2O film. The analysis shows that the decrease in the recombination probability of photogenerated carriers caused by the shift of the Fermi level and formation of an internal electric field is the main factor for the significant enhancement in the Cu2O photocatalytic performance. This article provides a novel method and idea to realize the efficient removal of organic dye pollutants in sewage.

Automated summary

In this study, a ZnO/Cu2O composite film with excellent photocatalytic performance was prepared using a codeposition method, with the M-2 sample demonstrating the highest efficiency. The outstanding performance of the ZnO/Cu2O composite film is mainly attributed to its high efficiency in separating photogenerated carriers and the significant shift in the Fermi level compared to pure Cu2O film.