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

In this study, a double Z-type Bi2MoO6/ZnSnO3/ZnO heterostructure photocatalyst was prepared by hydrothermal method to realize effective charge separation and improve photocatalytic activity. The synthesized samples were carefully examined by X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope, high-resolution transmission electron microscopy, 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 series of unique properties, such as a significant climb in light absorption properties and superior photocatalytic activity. In addition, compared to ZnO, Bi2MoO6 and ZnSnO3/ZnO, the Bi2MoO6/ZnSnO3/ZnO composite material shows lower PL intensity, smaller arc radius, and stronger photocurrent response. Meanwhile, Bi2MoO6/ZnSnO3/ZnO shows higher photocatalytic efficiency for 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 CV 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.