Solar, visible and UV light photocatalytic activity of CoWO4 for the decolourization of methyl orange

The photocatalyst CoWO4 was synthesized by co-precipitation method with slight modification and well characterized by FT-IR, UV-vis diffuse reflectance spectra, X-ray diffraction, AFM and field emission scanning electron microscope techniques. The elemental composition present in the photocatalyst was confirmed by recording EDX spectrum. The photocatalytic activity of CoWO4 for the decolourization of methyl orange (MO) was investigated under solar, visible and Ultra-Violet (UV) light irradiation. The remarkable photocatalytic decolourization of MO was achieved under solar and visible light irradiation than that of TiO2. The high surface area of 55.0527 m(2)/g enhances the adsorption of anionic dye MO on the surface of the positively charged catalyst at pH 3 thus increases the photocatalytic activity. Under UV light irradiation, photocatalytic activity increases which may be due to high energy of photons. The essential parameters such as amount of catalyst, dye concentration and initial pH influence the photocatalytic efficiency of CoWO4. The first order rate constant for the decolourization reaction was derived using Langmuir-Hinshelwood kinetic model.