Study of Transition Metal Ion Doped CdS Nanoparticles for Removal of Dye from Textile Wastewater

Simple and cost-effective co-precipitation route was employed to prepare pure and transition metal ions doped CdS nanoparticles using 2-mercaptoethanol as surfactant. Doping of Ni, Co and Fe ions to CdS nanoparticles have been characterized adopting various techniques. X-ray diffraction confirmed CdS has single cubic phase with crystal size varying from 1 to 2 nm. UV–Vis spectroscopy analysis reveals an increase in absorption intensity upon doping. From Raman spectra, small shift in wave number is observed with inclusion of dopants which may be attributed to optical phonon confinement. Scanning electron microscopy confirmed agglomerated spherical morphology and Cd–S linkage along with other related functional groups was recorded by Fourier transform infrared spectroscopy. Photocatalytic measurements of undoped and doped CdS were studied by irradiating methylene blue solution under visible light. It was observed that Co doped CdS effectively bleaches out methylene blue than Ni and Fe doped CdS upon exposure of visible light. This report also highlights effect of prepared nanoparticles in degradation of methylene blue by catalytic agent NaBH₄.