Structural, optical and photocatalytic investigations of cauliflower like SnO₂/CdS nanocomposite prepared by the sol-gel method

Crystal violet (CV), a cationic dye, has been established to be an extremely potent carcinogen, a mitotic toxin, and poisonous to mammalian cells. As a consequence, it is imperative to remove this specific dye before it is released into the environment because its presence inevitably has a devastating effect on humankind. The photocatalyst-mediated degradation of CV is a rapidly developing method of eliminating this hazardous dye from aqueous solutions, as demonstrated by the extensive reporting of its efficacy in recent times. In this study, we explore the photocatalytic activity of pure SnO₂, CdS and SnO₂/CdS nanocomposites which were fabricated by a facile sol-gel technique. Field emission scanning electron microscopic (FESEM) analysis revealed a cauliflower-like morphology for the SnO₂/CdS nanocomposite. The optical band gaps of the nanoparticles were found to be 2.41, 2.04 and 2.28 eV for the SnO_2, CdS, and SnO₂/CdS, respectively. Moreover, the SnO₂/CdS photocatalyst exhibits greater photocatalytic activity (73% degradation efficiency after 75 min) for the degradation of CV than that of the pure SnO₂ and CdS nanomaterials. This enhanced performance is attributed to enhanced charge separation and reduced charge recombination rates in the SnO₂/CdS photocatalyst activity, such that it could be used as a potential material to reduce water pollution in an economically viable way.