A facile and one-pot synthesis of pure and transition metals (M = Co & Ni) doped WO₃ nanoparticles for enhanced photocatalytic performance

Cobalt (Co) and Nickel (Ni) doped tungsten oxide (WO₃) nanoparticles were successfully synthesized by simple household microwave irradiation method without employing hydrothermal process. The samples have been characterized by various advanced techniques such as; powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV–Vis spectra, Photoluminescence and Fourier transform infrared spectroscopy (FT-IR) analysis. The X-ray diffraction reveals that all samples are monoclinic phase of WO₃ and the average crystalline size was observed to vary from 42 nm to 21 nm as the dopant content was introduced. The TEM images confirm the spherical shaped morphology and the size of the nanoparticles in nanoscale. The optical property of the pure WO₃ was significantly improved by dopant content, which is confirmed by UV and PL studies. The photo catalytic activity of the nanoparticles was studied in the degradation reaction of Crystal Violet (CV) and Methylene blue (MB) under UV light irradiation. It was found that Ni doped WO₃ showed superior performance of the photocatalytic activity of the pure WO₃. The improved photocatalytic mechanism by Ni doping was also discussed.