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.