Structural, photophysical and photocatalytic properties of new Bi2SbVO7 under visible light irradiation

Abstract

Bi₂SbVO₇ was prepared by solid-state reaction technique for the first time and the structural and photocatalytic properties of Bi₂SbVO₇ and Bi₂GaTaO₇ were investigated. The results showed that Bi₂SbVO₇ crystallized with the tetragonal crystal system by space groupI4/mmm. In addition, the band gaps of Bi₂SbVO₇ and Bi₂GaTaO₇ were estimated to be 2.33 and 2.52 eV. The photocatalytic degradation of aqueous methylene blue (MB) dye over Bi₂SbVO₇ and Bi₂GaTaO₇ was investigated under visible light irradiation. Bi₂SbVO₇ showed higher catalytic activity compared with Bi₂GaTaO₇ for MB photocatalytic degradation under visible light irradiation. The photocatalytic MB degradation followed first-order reaction kinetics, the apparent first-order rate constant k being 0.0262 and 0.0060 min⁻¹ with Bi₂SbVO₇ and Bi₂GaTaO₇, respectively. Complete removal of aqueous MB was realized after visible light irradiation for 210 min with Bi₂SbVO₇ as a catalyst. The reduction of the total organic carbon (TOC), the formation of inorganic products (SO₄²⁻ and NO₃⁻) and the evolution of CO₂ revealed complete removal of aqueous MB during the photocatalytic process by this novel photocatalyst.