Enhancement of photocatalytic activity of BiVO4 by barium doping

Abstract

BiVO₄ was successfully synthesized by solid state method and doped by barium in the sites of bismuth in 3%, 6%, 9% and 15% to form Bi_0.97Ba_0.03VO₄, Bi_0.94Ba_0.06VO₄, Bi_0.91Ba_0.09VO₄ and Bi_0.85Ba_0.15VO₄ respectively. The products were characterized using powder X-ray diffraction, diffuse reflectance spectroscopy, scanning electron microscopy and photoluminescence spectroscopy. The band gap of undoped BiVO₄ was calculated to be 2.19 eV and the barium doped BiVO₄ compounds exhibit band gaps which are closer to the band gap of undoped compound. The photocatalytic activities of undoped and doped catalysts for the degradation of methylene blue were studied using UV-Visible spectroscopy and found to be depended largely on the barium content and the particle size of the compounds.