Low-temperature synthesis of Cr2WO6 and its enhanced photocatalytic activity by N-doping

Abstract

Nano sized inverse trirutiles of composition Cr₂WO₆ and N-doped Cr₂WO₆ have been prepared by sol-gel and solid state methods respectively. Urea has been used as a source of nitrogen for N-doping. These trirutiles have been characterized by powder X-ray diffraction (PXRD), FT-IR, TGA, scanning electron microscopy (SEM), energy dispersive spectra (EDS), and UV-visible diffuse reflectance spectroscopy (UV-vis DRS). N-doped Cr₂WO₆ is crystallized in the tetragonal lattice with space group P4₂/mnm (136). The bandgap energy of both parent and N-doped materials is deduced from their UV-visible DRS profiles. The photocatalytic degradation of methylene blue and methyl violet aqueous solutions have been investigated using these oxides. Compared to the parent material, nitrogen doped Cr₂WO₆ exhibits ~ 30% and ~ 20 % increase in visible light-induced photo-degradation of the methylene blue (MB) and methyl violet (MV), respectively.