Versatile application of BiVO4/TiO2 S-scheme photocatalyst: Photocatalytic CO2 and Cr(VI) reduction

Chemosphere. 2023 Oct:337:139397. doi: 10.1016/j.chemosphere.2023.139397. Epub 2023 Jul 3.

Abstract

Herein, the synthesis, characterization, and reduction properties of 2D TiO2 aerogel powder decorated with BiVO4 (TiO2/BiVO4) were investigated for versatile applications. First, 2D TiO2 was prepared via lyophilization and subsequently modified with BiVO4 using a wet impregnation method. The morphology, structure, composition, and optical properties were evaluated using transmission electron microscopy (TEM), X-ray diffractometry (XRD), laser-induced breakdown spectroscopy (LIBS), and diffuse reflectance spectroscopy (DRS), respectively. Significantly enhanced photocurrent densities (by 3-15 times) were obtained for TiO2/BiVO4 compared to those of pure TiO2 and BiVO4. The reduction of toxic Cr(VI) to Cr(III) was assessed, including the effect of pH on overall photocatalytic efficiency. Under acidic conditions (pH ∼ 2), Cr(VI) reduction efficiency reached 100% within 2 h. For photocatalytic CO2 reduction, the highest yields of CH4 and CO were obtained using TiO2/BiVO4. A higher efficiency for both applications was achieved because of the better separation of the electron-hole pairs in TiO2/BiVO4. The excellent stability of TiO2/BiVO4 over repeated runs highlights its potential for use in versatile environmental applications. The efficiency of TiO2/BiVO4 is due to the interplay of the structure, morphology, composition, and photoelectrochemical properties that favour the material for the presented herein photocatalytic applications.

Keywords: BiVO(4); CO(2) reduction; Cr(VI) reduction; Photocatalysis; TiO(2).

MeSH terms

  • Carbon Dioxide*
  • Chromium / chemistry
  • Light*

Substances

  • chromium hexavalent ion
  • titanium dioxide
  • Carbon Dioxide
  • Chromium