Eswaran Kamaraj, Kavitha Balasubramani,
Volume 21, Issue 2 (June 2024)
Abstract
Heterostructure photocatalyst of CuWO4 modified SnO2 (CuWO4/SnO2) was fabricated by in simple wet-impregnation process and evaluated via degradation of rose Bengal (RB) under visible light irradiation. The samples had been completely characterized by Ultraviolet-visible diffuse reflectance spectroscopy (UV-vis-DRS), X-ray diffraction (XRD), Scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), High-resolution TEM (HR-TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett and Teller surface analysis (BET). The result divulged that amongst the catalysts, CuWO4/SnO2 displayed higher photocatalytic activity than CuWO4 or SnO2. The enhanced photocatalytic efficiencies are attributed to the charge transfer from SnO2 to CuWO4 nanoparticles, which efficiently decrease electron-hole recombination energy level. The time required for maximum degradation of rosebengal (RB) under visible light over CuWO4/SnO2 was 180 min. The other parameters such as pH (pH=8), photocatalyst dosage (0.2 g/L) and dye concentration (20 µM) were optimized to achieve high degradation efficiency (98.5%). The excellent photocatalytic activity of CuWO4/SnO2 is due to efficient separation of photogenerated electron-hole pairs. The holes (h+) and superoxide radicals (O2•-) are the reactive species involved in photocatalytic mechanism for gdegradation of RB.
