A simple and low-cost new procedure for synthesis of nickel(II) and cadmium(II) sulfides in situ thiourea metal–chelation precursor

ABSTRACT. Nickel(II) and cadmium(II) sulfides are a promising chemical material in various advanced research areas such as solar cells, supercapacitors, catalysts, and of significant interest for their practical implementations in up to photonics and electronics. Cadmium and nickel sulfides were synthesized with stoichiometries in aqueous media at elevated temperature from Ni(NO3)2.6H2O, NiCl2.6H2O, NiSO4.6H2O, CdCl2, Cd(NO3)2.4H2O, CdSO4.8H2O and thiourea as a sulfur precursor using a direct chemical reaction. At room temperature an octahedral and tetrahedral geometries result from the reactions between different nickel(II), cadmium(II) and thiourea with the molecular formulas can be presented as [Ni(NH2CSNH2)6]X2 and [Cd(NH2CSNH2)4]X2 where X = Cl-, NO3-, SO42. The novelty of our study is precipitated yellow cadmium sulfide and black nickel sulfide at elevated temperature ~80 oC through the molar ratio 1:10 (M2+: thiourea) in aqueous media. Infrared spectra, XRD, TEM including EDX, and elemental analysis were used for characterization the metal sulfides products. The average crystalline size of obtained CdS and NiS particles in range 20-25 nm. Different reaction conditions effects were evaluated on the size, morphology and particle size.   KEY WORDS: Nickel and cadmium sulfide, Chelation, Thiourea, XRD, TEM Bull. Chem. Soc. Ethiop. 2023, 37(3), 663-674.                                                           DOI: https://dx.doi.org/10.4314/bcse.v37i3.10