ROLE OF CALCINATION TEMPERATURES ON THE STRUCTURAL AND OPTICAL PROPERTIES OF NiO NANOPARTICLES

Abstract

Nickel oxide nanoparticles (NiO NPs) were synthesized through template free sol–gel method. Synthesized particles were calcined at 300∘C, 500∘C and 700∘C for 2[Formula: see text]h and further the particles were characterized for its thermal, functional, structural, morphological and optical properties. The peak broadening analysis was undertaken in order to calculate the variation in size and strain components of the particles with the calcinations temperature. The Debye–Scherer, Williamson–Hall and Size-strain plot methods were employed in peak broadening analysis and were compared with TEM results. All the NiO NPs crystallite size and lattice strain value were found to be in good agreement with all the models. The TEM analysis revealed that the calcinations at 700∘C NiO NPs have sphere like structure of less than 20[Formula: see text]nm particles size value. The strong peak observed at 360.5[Formula: see text]nm bandgap emission relates to the bandgap of 3.44[Formula: see text]eV which is because of the near band edge emission.