Visible Light Active BiVO4 Photocatalyst by Flame Spray Pyrolysis

  • Yung Kent Kho, ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Sciences and Engineering, The University of NSW, Australia
  • Wey Yang Teoh, ARC Centre of Excellence for Functional Nanomaterials, School of Chemical Sciences and Engineering, The University of NSW, Australia
  • Lutz Maedler, Foundation Institute for Materials Science, Department of Production Engineering University Bremen, Germany
  • Akihiko Kudo, Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Japan
  • Rose Amal, ARC Centre for Functional Nanomaterials, School of Chemical Engineering and Industrial Chemistry, The University of New South

    • The utilisation of visible light (&lambda>400 nm), the most abundant component of solar spectrum, in conventional photocatalysis has long been met with difficult challenges. Bismuth containing oxides have lately emerged as the candidates of visible light sensitive oxides.1-4 In particular, BiVO4, is an attractive materials stemming from its exclusivity in participating in photocatalytic water splitting 5 and organics degradation.6

    The presentation describes the rapid synthesis of BiVO4 nanoparticles via one-step Flame Spray Pyrolysis (FSP). Particles ranging from 10 to 90 nm were prepared and assessed for photocatalytic oxygen evolution and photo-oxidation of organic contaminants. BiVO4 photocatalysts prepared by FSP has bandgap energy of 2.50 - 2.60eV.

    Crystal structure and defects in the powder are expected to play a significant role in determining the photocatalytic activity. A scheelite-monoclinic BiVO4 with minimum defects is desirable for photocatalytic oxygen evolution. When prepared at lower rate of combustion enthalpy BiVO4 has showed low or negligible activity. This is attributed by the inappropriate structure, together with defects such as oxygen vacancy in the powder. The characteristics of BiVO4 photocatalyst have been improved by allowing the particle to reside longer in the flame. This, not only increased the particle size, but also allows formation of fully ordered crystal. Photocatalysts contained mainly monoclinic structure and have reduced oxygen vacancy were obtained. Enhancement in the photocatalytic activity has been observed on these particles.

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