High-performance photocatalytic WO3 nanoparticles for treatment of acidic wastewater

Water treatment is a worldwide problem that can be solved by the interaction of light with nanoparticles like WO3 nanoparticles. However, most nanoparticles have low photocatalytic efficiency in acidic conditions like acidic effluents of factories. Therefore, in the study, WO3 nanoparticles are synthesized with the sol-gel route as a simple and low-cost method, and then the nanostructures are calcined at a different temperature to find an effective photocatalytic agent for acidic water treatment. For the purpose, optical and structural properties, crystallinity, thermodynamic stability, and hydrodynamic diameter of the nanostructures are investigated in the paper. Raman and FTIR spectra of all four samples have approximately similar peaks and indicate the formation of WO3. XRD and thermal analysis point to a transition in the crystal phase with a change in calcination temperature. According to FESEM, DLS, and optical analyses, the as-synthesized and calcined WO3 nanoparticles @300 degrees C have the smallest particle size, the most stability in a liquid medium, and the best optical properties among other samples. The photocatalytic activities of these samples are evaluated via degradation of methylene blue, MB, (10 ppm) using irradiated WO3 NPs (20 ppm) under diode laser light with a central wavelength of 405 nm and the power of 100 mW. The high photocatalytic efficiency is obtained using the as-synthesized sample in both neutral (57.3%,) and acidic (74.7%) conditions and unlike most nanoparticles, the photocatalytic efficiency of the sample in acidic conditions is noteworthy, which makes it a suitable candidate for the treatment of acidic effluents in factories. [GRAPHICS] .