Influence of Morphology and Common Oxidants on the Photocatalytic Property of β-SnWO₄ Nanoparticles

In this paper, we report a simple, cost effective and surfactant-free method for synthesizing different morphology of β-SnWO₄ with irregular, spherical, flake-like and leaf-like structures by using sonochemical method followed by calcination. A well dispersed and highly crystalline β-SnWO₄ crystallites with various sizes have been prepared. The samples were characterized by using X-ray diffraction (XRD), scanning electron microscope (SEM), UV-vis spectroscopy, particle size and Zeta potential analyser. The SEM images reveal the successful preparation of an irregular, spherical, flake-like and leaf-like structure of β-SnWO₄. The absorption maximum of as-prepared different structures of β-SnWO₄ was observed in visible region. The degradation efficiency was found to be increased in leaf-like structures compared to irregular, spherical and flake-like structures of β-SnWO₄. Further, an enhanced photocatalytic effect was observed in leaf-like β-SnWO₄ nanoparticles while the common oxidants such as peroxomonosulphate (PMS), peroxodisulphate (PDS) and hydrogen peroxide (H₂O₂) were added. The degradation efficiency of these oxidants was found in the order of PMS > H₂O₂ > PDS. Generally these oxidants act as electron scavengers. From our experimental results, it is found that maximum efficiency of 93% was achieved when PMS was added. This shows the vital role of common oxidants in photocatalytic characteristics and their future applications in waste-water treatment.