A polyacrylamide gel route to photocatalytically active BiVO4 particles with monoclinic scheelite structure

Sphere-like BiVO4 particles with average size ranging from 390 to 270 nm were prepared via a polyacrylamide gel route, where the particle size was tailored by using different chelating agents. The bandgap energy of the samples is measured to be 2.49–2.51 eV by ultraviolet–visible diffuse reflectance spectroscopy. The photocatalytic activity of the samples was evaluated by the degradation of methylene blue under irradiation of simulated sunlight, revealing that they exhibit a good photocatalytic activity. Hydroxyl radicals were detected by the photoluminescence technique using terephthalic acid as a probe molecule and are found to be produced over the irradiated BiVO4 particles. This indicates that hydroxyl radicals are likely to be the primary active species responsible for the dye degradation.