Photocatalytic activity of Natural clay Bentonite supported ZnWO4

Abstract

Natural clay Bentonite supported ZnWO₄ has been successfully synthesised through hydrothermal-thermal decomposition method. The experimental results reveal that 12wt% of Bentonite supported ZnWO₄ exhibited the higher photocatalytic activity for the degradation of azo dyes (Rhodamine-B (Rh-B) and Methylene Blue (MB) under UV light than undoped ZnWO_4. Bentonite - ZnWO₄ (BZW) was characterized by X–ray powder diffraction (XRD), field emission scanning electron microscopy (FE–SEM), energy dispersive spectroscopy (EDS), field emission transmission electron microscopy (FE–TEM), X-ray photo electron spectroscopy (XPS), Photoluminescence spectroscopy (PL), UV–Vis diffuse reflectance spectroscopy (DRS) and BET surface area analysis. FESEM images reveal the formation of nanoflakes, which are joined together by an edge-to-flat-surface conjunction. From the BET analysis it is found that BZW has higher surface than undoped ZnWO₄. As synthesized Bentonite supported ZnO has high recyclability for four successive cycles.