Microwave-assisted hydrothermal synthesis of chrysanthemum-like Ag/ZnO prismatic nanorods and their photocatalytic properties with multiple modes for dye degradation and hydrogen production

Abstract

A series of Ag/ZnO composites were prepared by microwave-assisted hydrothermal synthesis. Their composition, structure, and morphology were well characterized by X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (UV-vis/DRS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and N₂ adsorption–desorption analyses. The results showed that the microwave-assisted synthesis method did not significantly alter the crystal structure of the composites. However, light absorption by the composite was clearly enhanced, its Brunauer–Emmett–Teller surface area values changed, and excellent surface morphology was observed. Moreover, the Ag/ZnO composite formed via microwave-assisted hydrothermal synthesis exhibited more regular stacking piled into a chrysanthemum-like structure. Under ultraviolet, visible-light, simulated sunlight, and microwave-assisted irradiation, the composite exhibited better photocatalytic properties for the photocatalytic degradation of rhodamine B compared to that of P25 and ZnO. Moreover, the composite was investigated as a catalyst for the degradation of four dyes with different structures under UV conditions, exhibiting good degradation performance. Furthermore, the degradation efficiency did not change significantly after three cycles, indicating a certain degree of stability. In addition, the photocatalytic hydrogen production experiments showed that the nanocomposite Ag/ZnO had some ability to produce photocatalytic hydrogen.