Synthesis of Needle-Like BiVO₄ with Improved Photocatalytic Activity Under Visible Light Irradiation

Abstract

A highly crystallized monoclinic-scheelite type BiVO₄ powder was successfully synthesized using the solvothermal method. The as-synthesized BiVO₄ powder was characterized by XRD, FE-SEM, Raman spectroscopy, UV-Vis DRS spectroscopy, and TA-PL. Based on the XRD data and Raman spectra, the monoclinic-scheelite type BiVO₄ samples can be obtained at solvothermal synthesis temperatures higher than 140 °C. The preparation conditions, such as the Bi/V molar ratio and synthesis temperature, play an important role in controlling the morphologies of the BiVO₄ samples. The BVO 2 sample shows the highest photocatalytic activity, as well as the highest formation rate of OH radicals and the highest PL peak. This result suggests that the formation rate of OH radicals is well correlated with the photocatalytic activity.