Preparation of Dual Z-scheme Bi2MoO6/ZnSnO3/ZnO Heterostructure Photocatalyst for Efficient Visible Light Degradation of Organic Pollutants

An important means of achieving efficient charge separation and improving photocatalytic activity is the construction of heterostructures. In this study, the Bi2MoO6/ZnSnO3/ZnO heterostructure photocatalyst was synthesized by the hydrothermal method. The synthesized samples were carefully examined by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscope (SEM), high-resolution transmission electron microscopy (HR-TEM), photoluminescence (PL), and other analytical techniques. Meanwhile, the photocatalytic performance was further evaluated by multi-mode photocatalytic degradation with crystal violet (CV). The results show that the composite material has a relatively homogeneous cubic structure in size and shape. In the cubic structure, a heterogeneous structure exists between Bi2MoO6, ZnSnO3 and ZnO. Simultaneously, the dramatic changes in physical morphology, such as the specific surface area and particle size of the composites, led to a unique set of properties, such as a significant climb in light absorption properties and superior photocatalytic activity. In addition, the Bi2MoO6/ZnSnO3/ZnO composite material shows lower photoluminescence intensity, smaller arc radius, and stronger photocurrent response compared to ZnO, Bi2MoO6 and ZnSnO3/ZnO. Meanwhile, Bi2MoO6/ZnSnO3/ZnO shows higher photocatalytic efficiency for crystal violet (CV) and tetracycline hydrochloride (TC) and maintains good stability after 3 cycles of photodegradation experiments. Based on experimental results, the existence of heterojunctions between ZnO, ZnSnO3 and Bi2MoO6 and the possible photocatalytic mechanism for the degradation of crystal violet by dual Z-scheme composites are proposed. In conclusion, this study provides a feasible strategy for the photocatalytic degradation of organic pollutants by introducing ZnSnO3 and Bi2MoO6 to successfully construct composite catalysts with dual Z-scheme heterostructures.