Effect of precursor concentration on structural and optical properties of nickel oxide nanoparticles synthesized by facile sol-gel method

Abstract

We report a simple, fast and efficient sol-gel technique to synthesize nickel oxide (NiO) nanoparticles of variable sizes. For this, three different precursor concentrations, viz. 0.1, 0.3, and 0.5 M were used. All the samples were maintained at a pH of 8 and calcined at 500 °C for 4 h. Our study shows the formation of well-crystalline, spherical, single-phase, pure NiO nanoparticles. The size of the nanoparticles increases with the concentration of the precursor solution. All nanoparticles show absorption peaks at the wavelength of ∼358 nm, which lie in the UV region and a near band edge emission peak at ∼390 nm.