Abstract: The Co-BiVO₄ photocatalyst was prepared by hydrothermal method and characterized by X-ray diffraction, scanning electron microscope, UV-Vis absorption spectroscope, and low-temperature N₂ adsorption. The characterized results indicate that highly crystalline monoclinic scheelite structure of Co-BiVO₄ is obtained at pH=7 and the Co dopant does not change the crystal phase of BiVO₄. The Co-BiVO₄ has a significant red-shift in the absorption band in the visible region, and its absorption intensity increases greatly for the doped catalyst compared with pure BiVO₄. Low-temperature N₂ adsorption result reveals that the pore size of the Cu-BiVO₄(pH=7) mostly distributes at 2.67 nm. The desulfurization ability of Co-BiVO₄ was researched by photocatalytic oxidation of thiophene in visible light. The results show that the Co-BiVO₄ photocatalysts exhibit higher photocatalytic activities for degradation of thiophene under visible light irradiation. When pH value is 7.0 and the hydrothermal synthesize time is 8 h, the photocatalytic activities reach the maximum. Under the conditions of 150 mL/min air flow, 1.0 mg/L catalyst amount, and visible light irradiation for 3 h in 400 W xenon lamp light, the desulfurization rate by Co-BiVO₄ at 600 mg/L initial concentration increases to 86%.

Key words: Co-BiVO₄, photocatalyst, oxidation desulfurization, thiophene