One-pot template-free synthesis of heterophase BiVO4 microspheres with enhanced photocatalytic activity

Abstract

A one-pot template-free hydrothermal method was developed for the fabrication of BiVO₄ microspheres with tetragonal-monoclinic heterophase structures. XRD and HRTEM characterization confirmed the formation of the heterophase structure. It was found that the molar ratio of Bi/V and hydrothermal time were critical parameters in the yield of the spherical morphology and heterophase structure. Benefiting from the unique morphology and existence of the heterophase, the as-prepared BiVO₄ microspheres exhibited improved efficiency for RhB degradation in comparison with pure monoclinic scheelite-type BiVO₄ and tetragonal zircon-type BiVO₄. EPR and TA-PL techniques proved that the photoinduced active species were involved in the photocatalytic degradation of RhB. The enhanced photocatalytic performance can be attributed to the more effective separation of photogenerated carriers generated in the heterophase BiVO₄ system, as evidenced by electrochemical measurements.