Synthesis of NiO Nanoparticles by Water-in-oil Microemulsion Technique

NiO nanoparticles were synthesized by water-in-oil microemulsion technique using Aerosol-OT as a surfactant. The study aims to understand the nanoparticle size and distribution synthesized with the surfactant and co-precipitated without surfactant. Nanoparticles were synthesized with different R-ratios (molar ratio of water to surfactant). It was found that particle size distribution is narrow within the microemulsion forming regime while the particles were polydispersed when synthesized outside the microemulsion forming regime at high R-ratio. In addition, co-precipitated nanoparticles were found to have a wide size distribution that was comparable to the nanoparticles synthesized at high R-ratio. Phase identification and particle size analysis were carried out using X-ray diffraction (XRD) and Transmission electron microscope (TEM).