Effect of anions on the morphology of CdS nanoparticles prepared via thermal decomposition of different cadmium thiourea complexes in a solvent and in the solid state

Abstract

Thermal decomposition of four different cadmium thiourea complexes as single source precursors in a solvent and in the solid state has been explored as an effective and convenient strategy for the controlled synthesis of CdS nanoparticles with unique morphologies for the first time. Thermal decomposition of four cadmium thiourea complexes with different anions (acetate, chloride, nitrate and sulfate) in diphenyl ether and solid state leads to CdS nanoparticles with different morphologies. The effect of anions on the structural, morphological and optical properties of CdS nanoparticles, prepared by both the methods, has been investigated. CdS nanoparticles derived from solid state thermal decomposition of the cadmium thiourea complexes with acetate, chloride, nitrate and sulfate ions exhibit spheres, nanotubes, nanoflowers and irregular morphologies, respectively. On the other hand, thermal decomposition of the cadmium thiourea complexes with acetate, chloride and nitrate ions in diphenyl ether results in CdS nanoparticles with microspheres, nanopyramids and a mixture of nanoparticles and nanorods morphologies, respectively. A detailed mechanism on the effect of anions on the morphology of CdS nanoparticles produced by both the methods has been proposed. The synthesized CdS nanoparticles with different morphologies have been explored as photocatalysts for the degradation of crystal violet in an aqueous solution under sunlight. The CdS nanoparticles prepared by thermal decomposition in the solid state possess higher photocatalytic efficiency than that prepared by thermal decomposition in the solvent.