Facile Construction of Heterostructured BiVO4–ZnO and Its Dual Application of Greater Solar Photocatalytic Activity and Self-Cleaning Property

Development of coupled semiconductor oxides makes a significant advancement in catalytic functional materials. In this article, we report the preparation of nanobundle-shaped BiVO4–ZnO photocatalyst by a simple hydrothermal process followed by thermal decomposition. The photocatalyst was characterized by X-ray powder diffraction (XRD), high-resolution scanning electron microscopy (HR-SEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL), and UV–vis diffuse reflectance spectroscopy (DRS). The XRD pattern confirmed formation of monoclinic scheelite BiVO4 and the hexagonal wurtzite structure of ZnO. HR-SEM images show nanobundle-like structure, and the size of the nanospheres ranges from 20 to 40 nm. BiVO4–ZnO has increased absorption in the UV and visible region when compared to ZnO. The catalytic activity of BiVO4–ZnO was evaluated by the photodegradation of Acid Violet 7 (AV 7), Evens Blue (EB), and Reactive Red 120 (RR 120). The results revealed that the photocatalytic activity of BiVO4–ZnO was much higher than that of ZnO, BiVO4, and TiO2–P25 under natural sunlight. BiVO4–ZnO is more advantageous than ZnO and BiVO4 in the degradation of AV 7, EB, and RR 120 because it has maximum efficiency at neutral pH 7. BiVO4–ZnO was found to be stable and reusable without appreciable loss of catalytic activity up to four consecutive cycles. The self-cleaning property of BiVO4–ZnO has been evaluated using contact angle measurements. Our results provide some new insights on the performance of solar active photocatalysts on environmental remediation.