Enhancement of photocatalytic degradation of an organic pollutant by WO3 nanopowders: carbon doping

Abstract

The photocatalytic activity of C doped WO₃ is monitored by studying the degradation of the methylene blue (MB) aqueous dye solution under visible light irradiation. The photocatalyst WO₃ was synthesized by the solvothermal method and modified by doping carbon into it in the molar ratio 1:1, 1:2, 1:3 and 1:4 under hydrothermal process. The photocatalysts were characterized for structural and optical properties. XRD was taken to identify the phase and structure, also confirms the successful incorporation of carbon into WO₃ lattice site. Morphology and elemental composition were analyzed using SEM and EDAX. The UV-DRS spectrum showed an increase in absorption intensity with increasing carbon content with decreases in bandgap from 3.0 eV to 2.6 eV. PL emission spectra gave blue emission (484 nm) and green emission (555 nm). Finally, the photocatalytic response graph of C doped WO₃ with time showed an excellent absorption property and an enhanced visible-light photocatalytic activity compared to pristine WO₃.