Facile synthesis of cerium and vanadium doped nickel oxide nanoparticles for the enhancement of optical, electrical and thermoelectric properties

To investigate the optical, electrical and thermoelectric properties of pristine, cerium and vanadium doped NiO-NPs was synthesized by using sol-gel method. The XRD was used to investigate the FCC cubic crystal structure and crystallite size decreased from 75 to 43 nm. However, SEM micrographs depicted irregular surface morphology changed into small agglomerated grains by vanadium doped NiO-NPs. After that the EDAX analysis was performed to obtain the elemental composition (Ni, O, Ce and V) and also identified the weight percent of each element in all samples. The different functional groups such as Ni-O, OH, C-O, CO2, C--C and V-O was examined by FTIR spectra. The absorbance peak of pristine and doped NiO NPs indicate the blue shift and band gap decreased from 3.52 to 3.30 eV was calculated by UV-VIS analysis. The electrical properties were examined with two probe method and draw the relation between resistivity and conductivity. It was observed that the resistivity decreased (6 x 103 to 2 x 103 ohm-cm) with Ce and V doped NiO-NPs and conductivity increased (2 x 10-5 to 6 x 10-3 S/cm). Further, seebeck coefficient was calculated with the help of thermoelectric analysis and it was observed that seebeck coefficient increased by increasing temperature upto significant level. Overall analyses shows that vanadium doped NiO-NPs are excellent candidate for optical, electrical and thermoelectric measurements. While as prepared cerium and vanadium doped NiO-NPs will be helpful of electrical and thermoelectric devices.