Microwave assisted synthesis of sheet-like Cu/BiVO₄ and its activities of various photocatalytic conditions

The Cu/BiVO₄ photocatalyst with visible-light responsivity was prepared by the microwave-assisted hydrothermal method. The phase structures, chemical composition and surface physicochemical properties were well-characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance absorption (UV–vis/DRS), scanning electron microscopy (SEM), and N₂ adsorption–desorption tests. Results indicate that the crystal structure of synthetic composite materials is mainly monoclinic scheelite BiVO₄, which is not changed with the increasing doping amount of Cu. In addition, the presence of Cu not only enlarges the range of the composite materials under the visible-light response, but also increases the BET value significantly. Compared to pure BiVO₄, 1% Cu/BiVO₄-160 performs the highest photocatalytic activity to degrade methylene blue under the irradiation of ultraviolet, visible and simulated sunlight. In addition, the capture experiments prove that the main active species was superoxide radicals during photocatalytic reaction. Moreover, the 1% Cu/BiVO₄-160 composite shows good photocatalytic stability after three times of recycling. - Graphical abstract: A series of BiVO₄ with different amounts of Cu doping were prepared by the microwave-assisted method, moreover, which performed the high photocatalytic activities to degrade methylene blue under multi-mode. - Highlights: • A series of Cu/BiVO₄ with different amounts of Cu doping were prepared by microwave-assisted synthesis. • The morphologies of as-samples were different with the amount of Cu doping increased. • Compared with pure BiVO₄, as-Cu/BiVO₄ showed stronger absorption in the visible light region obviously. • 1% Cu/BiVO₄-160 performed the high photocatalytic activities to degrade methylene blue under multi-mode. • OH^• and h⁺ both play important roles in the photocatalytic reaction