In situ grown ZnO nanoparticles using Begonia leaves–dielectric, magnetic, filter utility and tribological properties for mechano-electronic applications

Biogenic zinc oxide (ZnO) nanoparticles are successfully synthesized by solvothermal method using various concentrations Begonia leaf extract as capping agent. The single nano-crystalline wurtzite-type structure is confirmed by X-ray powder diffraction. HRTEM observations reveal spherical-shape particles at the nanoscale. The calculated optical band gap of 3.51 eV enables for optimum use in solar cell applications. It is found that both the dielectric constant and dielectric loss are inversely proportional to the frequency while both are directly proportional to the temperature. This implies that the charge transport process along with polarizability is impacted by the space charge. Magnetic measurements indicate the presence of weak ferromagnetic component attributed to oxygen vacancies, besides the existence of a magnetic transition from diamagnetic into paramagnetic. The filter utility and the mechanical–tribological parameters are also studied.