Development of solar driven photocatalyst and its application in degradation of organic pollutants

Development of solar driven photocatalyst and its application in degradation of organic pollutants Abstract In this project, core-shell CdS@SnO2 particles have been prepared by Successive Ion Layer Adsorption and Reaction (SILAR) method. CdS is a well known low band gap semiconductor (of band gap ~ 2.4eV) and can thus harvest visible light of wavelength up to 520nm of the solar radiation. In our present work, we have implemented SILAR method with slight modification to coat thin CdS layer over fine SnO 2 particles to obtain core-shell CdS@SnO 2 particles. The SILAR method, which is usually used for the deposition of binary semiconducting thin films, has some advantage over other preparative methods, for example, this is a facile, less expensive and less time consuming technique, and it provides the provision to control the thickness of the film by adjusting the number of cycle of coating. In the present synthetic approach, fine SnO 2 powder has been prepared by hydrothermal method initially. The synthesized SnO2powder has been used as a substrate over which the CdS layer has been coated to obtain powder photocatalyst. SnO2 is a large band gap semiconductor and has no impact on visible light absorption. The synthesized core shell type CdS@SnO 2composite photocatalyst has been characterized with FTIR technique. The activity of the synthesized photocatalyst has been investigated under visible light towards the photooxidative degradation of Rhodamine B (RhB), which is a toxic organic contaminant.