Synthesis Of BiVO₄ And Its Photocatalytic Activities Under Visible Light Irradiation

As important materials in the coatings and plastics industry, BiVO₄-based compounds have been extensively investigated over the past 2 decades, because they are lead-, cadmium- and chromate-free inorganic yellow pigments used to manufacture brilliant yellow shades with good gloss and hiding power.BiVO4 also exhibits various technological properties, such as photocatalytic activity, ferroelasticity, and conductivity, which depend strongly on crystalline form and microstructure. BiVO4 appears in three main crystalline forms: tetragonal zircon, monoclinic scheelite, and tetragonal scheelite structures. Monoclinic scheelite shows much higher photocatalytic activity under visible light irradiation and superior coloristic properties over the other forms.In this paper, a hydrothermal process that monoclinic scheelite generates BiVO₄ is described. Bi(NO₃)₃·5H₂O and NH₄VO₃ were used as the raw materials, and sodium dodecyl benzene sulfonate (SDBS) and sulfuric acid dimethyl ester(DMS) were used as the morphology-directing agent.At last, BiVO₄ samples were characterized by XRD, SEM, FTIR, UV-vis, BET et al. And photodecompose Methylene Blue under the visible lingt to check out the relationship between the crystalline forms and photocatalytic efficiency. It shows that adequate adding SDBS or DMS phase-pure monoclinic BiVO₄ can be formed. In addition, the phase-pure monoclinic BiVO₄ made by adding DMS show a higher photocatalytic activity than that made by adding SDBS for degradation of Methylene Blue under solar irradiation.