Facile synthesis and photocatalytic activity of monoclinic BiVO4 micro/nanostructures with controllable morphologies

Graphical abstract: Display Omitted Highlights: ► BiVO4 micro/nanostructures have been synthesized by a facile solvothermal method. ► The shapes of BiVO4 micro/nanostructures can be controlled by tuning the synthetic parameters. ► BiVO4 nanorods with rectangular cross sections exhibit improved photocatalytic activities. -- Abstract: Monoclinic BiVO4 (m-BiVO4) micro/nanostructures, such as nanorods, nanofibers, bundle-like nanostructures, and porous submicrometer-sized rods, have been successfully synthesized by a facile solvothermal method in an ethylene glycol–water–sodium oleate system. The morphologies and sizes of m-BiVO4 micro/nanostructures can be controlled by adjusting the synthetic parameters, such as the concentrations of sodium oleate and reaction time. Among them, the synthesized m-BiVO4 nanorods have rectangular cross sections, and can grow along the [0 0 1] direction, and are enclosed by well-defined facets, such as (0 0 2), (2 4 0), and (2¯10), which are distinct from that with circular cross sections. A crystallization-cleavage-disassembly process has been proposed for the formation of m-BiVO4 nanorods with rectangular cross sections. The photocatalytic activity of m-BiVO4 nanostructures is affected greatly by the sizes and shapes of m-BiVO4 nanostructures. Photocatalytic measurements show that the m-BiVO4 nanorods with rectangular cross sections exhibit higher photocatalytic activities of Rhodamine B in comparison with m-BiVO4 nanofibers with circular cross-sections and porous submicrometer-sized rods.