Sol–gel synthesis of SnO₂/CdS heterostructures using various Cd:S molar ratio solutions and its application in photocatalytic degradation of organic dyes

Synthesis of heterostructures of large band gap metal oxides coupled with chalcogenide semiconductors is an emerging area of research. They have been reported to be used as effective photocatlysts for purification of water in recent years. It can converts toxic organic pollutants into less or nontoxic compounds. In this present work we have reported synthesis of SnO₂/CdS heterostructures by two-step sol–gel route: In the first step, the synthesis of nano sized SnO₂ particles by sol gel method, and in the second step synthesis of of SnO₂/CdS heterostructures with CdS solution, in various molar ratios of cadmium and sulphur. Obtained samples were characterized by structural, morphological, electrical and optical studies. The photocatalytic behavior of the samples were also were studied. The samples demonstrate high photo catalytic degradation of methylene blue than individual SnO₂ due to effectual charge separation. Increasing sulfur content in the solution introduces an effective charge separation in the grown heterostructures resulted in diminished PL intensity. For heterostructures with higher sulfur content, photo catalytic performance reaches upto 96% photo degradation of methylene blue as compare to bare SnO₂ (26%) under the influence of UV and visible light irradiation. Obtained heterostructures are highly suitable for various industrial applications.