Synthesis and characterization of cadmium sulphide nanoparticles and its utilization in removal of cadmium from aqueous solution

Nanomaterials are the leading edge to the rapidly developing nanotechnology. For the synthesis of nanomaterials over a wide range of chemical composition, the development of reliable and efficient methods is a challenging issue in nanotechnology. In context to this green synthesis of nanoparticles using biological systems, plant products and microorganisms are potentially considerable because of its non-toxic and environmental friendly nature. The use of bacterial extracellular polymeric substances (EPS) is a current approach in the synthesis of nanoparticles. Cadmium sulphide (CdS) nanoparticles were synthesized by chemical method using glucose and biological method using EPS and surface functionalized EPS. EPS functionalization was carried out by attaching sulphur groups on its surface to synthesize CdS nanoparticles and simultaneous removal of cadmium from aqueous solution. The nanoparticles synthesized were characterized by UV-Visible spectrophotometer, XRD, ATR-FTIR and FESEM. The study also revealed that the percentage removal of cadmium from aqueous solution by the surface functionalized EPS was greater (80 %) than that of EPS (61%) which attributed to greater cadmium binding by sulphur group of the surface functionalized EPS. The percentage removal of cadmium also increased (83%) by using nanoparticle incorporated functionalized EPS, which provided a greater surface area for cadmium adsorption. Therefore, our work suggests that EPS functionalization is a feasible approach for CdS nanoparticles synthesis and removal of cadmium from aqueous solution