The synthesis of bismuth vanadate powders and their photocatalytic properties under visible light irradiation

Abstract

Bismuth vanadate powders were prepared by hydrothermal method with NaVO 3 and Bi(NO 3) 3 as starting materials and with Na 2CO 3 to adjust pH, and characterized by XRD, SEM, EDS and surface area analyzer. The results showed that the phase formation of bismuth vanadate depended on the adding amount of Na 2CO 3. The bismuth vanadate samples existed as monoclinic BiVO 4 by adding 0.019 and 0.038 mol of Na 2CO 3 with corresponding pH value of 0.2 and 5.8, respectively, and as Bi 4V 2O 11 by adding 0.057 mol of Na 2CO 3 with corresponding pH value of 9.7. The photocatalytic activities of the samples were evaluated by the decolorization of methylene blue (MB) under visible light irradiation. The sample with monoclinic form obtained by adding 0.019 mol of Na 2CO 3 had the highest photocatalytic activity, the decolorization rate of MB reached to 96.4% under visible light irradiation in 200 min and the reaction rate constant was 0.015 min −1.