Synthesis, characterization, and enhanced photocatalytic properties of NiWO4 nanobricks

Brick shaped nanoparticles of nickel tungstate (NiWO4) were synthesized magnificently using the molten salts process at 500 degrees C. Powder X-ray diffraction (PXRD) and electron microscopy measurements were carried out to investigate the phase purity, crystal structure, and morphology (size and shape) of the NiWO4 nanobricks (diameters of similar to 20 nm). The BET surface area of the NiWO4 nanobricks was found to be similar to 25 m(2) g(-1). The optical properties of the NiWO4 nanobricks demonstrate a direct band gap of 2.95 eV. Thereupon, the photocatalytic activities of the NiWO4 nanobricks have been investigated for the degradation of methylene blue (MB) dye in neutral and basic media under solar light irradiation (SLI). The NiWO4 nanobricks show significant enhancement in the photo-degradation of MB dye solution in alkaline (similar to 100% in 50 minutes) and neutral media (similar to 80% in 330 minutes) as compared to bulk NiWO4 and previous reports of metal tungstate. ESI mass spectrometry was also carried out to confirm the photocatalytic degradation of dye molecules.