Preparation and photoelectrochemical properties of TiO2/ZnO nanorod heterojunction arrays

In this study, a new process for preparing nanorod arrays was developed. The prepared nanorod array structure is innovative and the components of the prepared nanorod array can be replaced and expanded. The magnetron sputtering has been used to deposit the TiO2 and ZnO seed layer, which could promote the growth of nanorod arrays and is conducive to the improvement of the array morphology and structure, thereby enhancing the photovoltaic properties of the materials. The TiO2/ZnO nanorod array heterojunction materials were prepared using a secondary hydrothermal method combined with magnetron sputtering. The microscopic morphology, crystal structure, absorption spectrum, reflection spectrum, and photoelectrochemical performance of the samples were investigated using scanning electron microscopy, X-ray diffractometry, UV–vis spectrophotometry, and electrochemical workstation, respectively. The experimental results show that the prepared TiO2/ZnO nanorod array heterojunctions exhibit a typical bilayer nanorod array structure with high crystallization; the TiO2/ZnO nanorod heterojunction array has a higher degradation efficiency with a 98% degradation rate of methylene blue (80 min), where there are only 84.5% and 89.6% of methylene blue degraded by the TiO2 and ZnO nanorod arrays, respectively. The photoelectrochemical properties and photocatalytic ability of the TiO2/ZnO nanorod array heterojunctions are significantly superior to those of the single-component ZnO or TiO2 nanorod arrays. SnO2/TiO2 nanorod heterojunction arrays and SnO2/ZnO nanorod heterojunction arrays were also prepared using this process, indicating promising application prospects.