Synthesis of metal-semiconductor heterostructure for organic pollutants degradation

Abstract

Water pollution posed by organic pollutants has increased both human’s health and ecological problem. Using TiO2 for photocatalytic degradation of these harmful pollutants has been popular due to its cheap and chemical stability. However, TiO2 poses a limitation which is not being able to efficiently tap on the solar energy due to its large band gap. Hence previous study was done on cadmium based semiconductor nanocrystals for the improvement of the degradation rate. Although cadmium based semiconductor nanocrystals are able to drive visible light photo catalysis, cadmium itself poses as toxic chemical if not filter out completely from the water system. In this project, three kinds of metal-semiconductor heterostructure were synthesized and tested for their photocatalytic performance, namely, Au-CuS Au-In2S3 and Au-CuInS2. Copper and indium sulfide based nanocrystals proposed potential application in the photocatalytic reaction due to their low toxic, tunable and wide absorption bandwidth in the visible light range properties. For the recyclability testing, Au-CuInS2 managed to achieve almost 95.4% degradation in the first cycle of Rhodamine B in the presence of lactic acid as compared to CdS (95.2%), Au-In2S3 (40%) and Au-CuS (21%).