Synthesis,characterization, multifunctional electrochemical (OGR/ORR/SCs) and photodegradable activities of ZnWO4 nanobricks

Brick-shaped zinc tungstate nanoparticles have been synthesized by ecofriendly solvent-free process using molten salts. Zinc tungstate nanobricks (ZnWO₄ Nbs) were characterized by powder x-ray diffraction (PXRD), FTIR, Raman, energy dispersive and electron microscopic studies. ZnWO₄ Nbs are used as the multifunctional electrode materials to oxygen generation reactions (OGR), oxygen reduction reactions (ORR) and supercapacitors (SCs) as well as photo-catalysts in the waste-water treatment by the degradation of organic dyes. Low overpotential (?₁₀?=?0.475?V), low tafel slope (140?mV/dec), high current density (~70?mA/cm²) and good stability of the electrodes are the key results of the present studies for water electrolysis (OGR/ORR). ZnWO₄ Nbs have also shown great interest in supercapacitors with efficient charge–discharge activities in 1?M KOH. The specific capacitance and energy density of ZnWO₄ Nbs were found to be 250?F/g and 80?Wh/kg, respectively, at 5?mV/s, these values are relatively higher than that of previously reported specific capacitance and energy density value of metal tungstate nanoparticles. ZnWO₄ Nbs as the photo-catalysts work very significantly for photocatalytic degradation of aqueous MB dye solution (~85 % in 3?h) in neutral medium.

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ZnWO₄ Nanobricks show significant multifunctional electro-chemical activities in alkaline medium and photocatalytic degradation of organic dye in neutral medium.