doi:10.1038/nindia.2013.124 Published online 17 September 2013
Researchers have fabricated tiny microspheres of cadmium sulfide (CdS) that can harness visible light to degrade a harmful organic dye . These microspheres can be used as a photocatalyst for treating polluted wastewater produced by the dye industry.
To develop a photocatalyst that can degrade organic dye under visible light, the researchers synthesized cauliflower-shaped microspheres of CdS using cadmium acetate dihydrate, oleic acid — a fatty acid — and thiourea. The pollutant-degrading efficiency of the CdS microspheres was tested by preparing an aqueous solution of rhodamine B (RhB), a harmful organic dye.
The study found that the CdS microspheres degraded around 90 per cent of RhB after exposure to visible light for 180 minutes. Increasing the light exposure time reduced the dye concentration. The microspheres generated hydroxyl radicals, which broke the RhB down into harmless compounds.
"These microspheres can be used in dye industries for treating wastewater that contains organic dyes as pollutants," says study co-author Jayesh Patel. He adds that the technique for producing such microspheres may also be useful for synthesizing other metal sulfide nanostructures for different applications.