LI Wentao, OUYANG Siyi, CHENG Zhaolin, LIU Xin, LI Jiake

(School of Materials Science and Engineering, Jingdezhen Ceramic University, Jingdezhen 333403, Jiangxi, China)

Abstract: Bi2WO6 was synthesized by using hydrothermal method, with Bi(NO3)3·5H2O and Na2WO4·2H2O as raw materials, and NaOH and HNO3 for pH value adjustment. The effect of pH value of the precursor solution on morphology and photocatalytic performance of Bi2WO6 was studied. Phase composition, morphology, specific surface area and light absorption of the as-synthesized Bi2WO6 were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), BET and UV-VIS diffuse reflectance spectroscopy. The photocatalytic activity of Bi2WO6 was evaluated through the degradation of methylene blue solution (10 mg·L−1) under the irradiation of mercury lamp. It was found that morphology and photocatalytic performance of Bi2WO6 are remarkably dependent on pH value of the precursor solution. When pH value of the precursor solution is 4, the as-synthesized Bi2WO6 showed spherical morphology, with the smallest band gap (2.50 eV) and large specific surface area (30.48 m2·g−1), so it exhibited the highest photocatalytic activity. The degradation rate of methylene blue solution is 96.8% after irradiation for 120 min, while the photocatalytic reaction is in accordance with the first-order reaction kinetics.

Key words: hydrothermal method; pH value; Bi2WO6; morphology; photocatalysis