Effect of Fe/Cd/O doping on the physicochemical properties of α-NiS nanocrystals

Effect of Fe/Cd/O doping on the physicochemical properties of α-NiS nanocrystals (exhibiting useful optical, electronic, and optoelectronic properties) has been studied by preparing the Fe/Cd/O-doped (2.5/5.0 mol%) α-NiS nanocrystals using a pulsed microwave heating method and characterizing them chemically and physically using the available standard methods. X-ray diffraction and energy-dispersive X-ray absorption analyses confirm the phase purity. Atomic force microscopic analysis shows the average particle sizes within 19–20 nm; scanning electron microscopic analysis indicates the spherical shape and homogeneity of the nanocrystals prepared. Optical and magnetic measurements indicate that doping has significantly modified the optical absorption coefficient (with bandgap energy values in the range of 3.62–4.73 eV), photoluminescence yield, and ferromagnetic ordering. Electrical (DC/AC) measurements made at various temperatures (40–150 °C) and frequencies (10²–10⁶ Hz) indicate a normal electrical behavior and increase of electrical/electronic conductivity and dielectric constant due to doping. The study indicates that oxygen (anionic) doping makes α-NiS nanocrystals a better electrochemical sensing performer and cathode material for use in storage batteries.