Optical, electrical and visible light-photocatalytic properties of yttrium-substituted BiVO4 nanoparticles

Abstract

• Y-substituted BiVO 4 nanoparticles are synthesized by hydrothermal method. • 11.3% Y-substituted BiVO 4 provides lowest charge transfer resistance. • 11.3% Y-substituted BiVO 4 exhibits largest photocatalytic activity. Yttrium-substituted (11.3 and 30.7 at.%) BiVO 4 and pristine BiVO 4 nanoparticles were synthesized by hydrothermal method. They were characterized by high resolution scanning electron, field emission scanning electron, transmission electron and high resolution transmission electron microscopies, powder X-ray diffraction, and energy dispersive X-ray, Raman, UV–vis diffuse reflectance, photoluminescence and solid state impedance spectroscopies. Y-substitution favors transformation of monoclinic phase of BiVO 4 to tetragonal phase. High Y-substitution increases the crystallite size as well as the band gap energy and enhances charger carrier recombination. The charge transfer resistance of 11.3% Y-substituted BiVO 4 is much less than those of the others. The visible light photocatalytic activity of 11.3% Y-substituted BiVO 4 nanoparticles is larger than the rest. The larger photocatalytic activity of 11.3% Y-substituted BiVO 4 nanoparticles has been explained in terms of mean crystallite size, recombination of photoformed electron–hole pairs and charge transfer resistance.