Composition-Controlled Synthesis of Bismuth Vanadate Photocatalysts Via a Facile Electrochemical Method

Bismuth vanadate compounds including BiVO4, Bi25VO40, and the composite Bi25VO40/Bi7V11O9 with photocatalytic properties were firstly synthesized via a facile electrochemical strategy. The amount of NaOH in the electrolyte and electric currents were discovered to be crucial variables to the composition, morphology, and crystallinity of the products. Monoclinic phase BiVO4 and Bi25VO40 with sillenite structure can be obtained at 2 A with NaOH concentration of 0-10(-4) and 0.1-0.4M, respectively. The acquirement of Bi25VO40/Bi7V11O9 can be achieved with electric current 3-5 A in an electrolyte containing 0.4M NaOH. All the electrosynthesized samples exhibit good visible-light-driven photocatalytic activity in the degradation of rhodamine B, much higher than that of the commercial TiO2 (P25).