A novel BiVO4 hierarchical nanostructure: controllable synthesis, growth mechanism, and application in photocatalysis

A novel BiVO4 hierarchical nanostructure assembled by nanorods was realized via a facile and additive-free solvothermal method. Based on the electron microscope observations, the growth of such architectures with “rod to dumbbell to sphere” transformation has been proposed as a crystal splitting growth process. Ethylene glycol (EG) instead of organic surfactant played an important dual role during the process. Different shapes were obtained by controlling the synthetic parameters. The as-prepared BiVO4 hierarchical nanostructures exhibited excellent visible-light-driven photocatalytic efficiency, which was increased to nearly 20 times than that of the products prepared by traditional solid-state reaction (SSR) and the nitrogen doped TiO2 (N–TiO2). Moreover, the photocatalyst could settle immediately, which is beneficial for the separation and recycle considering their future applications in waste water treatment.