Influence of different milling media on structural, morphological and optical properties of the ZnO nanoparticles synthesized by ball milling process

Abstract

ZnO nanoparticles were synthesized by ball milling process using four different milling media namely, DI water, ethanol, iso-propanol and DMF. The influence of these milling media on structural and optical properties of ZnO nanoparticles has been investigated. The X-ray diffraction and SAED analysis have been carried out to reveal structure of ZnO nanoparticles. Crystallite size and micro-strain of nanoparticles have been calculated using Scherer's formula and Williamson-Hall plots. Rietveld refinement of obtained XRD patterns has been carried out for estimation of structural and micro-structural parameters. It has been observed that structural attributes such as lattice parameters, unit cell volume, dislocation density, specific area, bond length and bond angle vary with milling media. Vibrational properties have been investigated with the help of FTIR and Raman spectroscopy. Morphological variation of particles with milling media has been revealed by FESEM and TEM investigation. Optical parameters namely, band gap energy, refractive index, extinction coefficient, dielectric constants, dielectric loss and optical conductivity have been evaluated using UV–Visible spectroscopy. The band gap values of particle synthesized in different milling media have been found in the range of 3.32–3.37 eV. Photoluminescence (PL) spectroscopy of nanoparticles has been performed to investigate the type of defects present. The study reveal that tailoring of structural and optical parameters with milling media can be done by selecting different milling media.