High photocatalytic activity N-doped Bi2WO6 nanoparticles using a two-step microwave-assisted and hydrothermal synthesis

Abstract

High quality N-doped Bi2WO6 nanoparticles were synthesized using a two-step microwave-assisted and hydrothermal method. The morphological, structural, compositional and optical properties of the samples were investigated using a scanning electron microscope, N2 adsorption/desorption, X-ray diffraction, X-ray photoelectron spectroscopy, UV-VIS diffuse reflectance and photoluminescence. The photocatalytic activity of the samples was studied using visible light irradiation of rhodamine B. Our results show that this two-step synthesis and N-doping are both helpful in enhancing the photocatalytic activity of Bi2WO6 nanoparticles, and that N-doping plays a more important role than the two-step synthesis. The best photocatalytic activity can be achieved by the N-doping of N:Bi = 0.5% (atomic ratio), which is mainly due to the greatest decrease in recombination rate of photogenerated electron-hole pairs obtained with this doping content. In addition, the photocatalytic mechanism study indicated that the photogenerated holes are the dominant active species in the photocatalytic process.