Synthesis of zinc oxide nanoparticles with different pH by aqueous solution growth technique

Highly dispersible zinc oxide nanoparticles were produced via a simple aqueous solution growth technique. The effect of concentration of ionic liquid [benzyltrimethylammoium hydroxide IL (BTMAH)] and pH on morphology and optical properties of zinc oxide nanoparticles has been extensively investigated. The average crystalline size of ZnO nanoparticles decreases with increasing pH. A sharp visible emission was observed in as-prepared ZnO nanoparticles. Crystallinity, phase purity, nanostructures and average grain size were confirmed by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Hexagonal wurtzite phase structure of ZnO nanoparticles was obtained in the form of spheres for all the three samples. pH increased, the broadening (FWHM) of the diffraction peaks increased and the intensities of diffraction line decreased. The emission wavelength was observed through photoluminescence spectroscopy.