Energy Efficient and Size Tunable Synthesis of ‘Colloidal’ Zinc Oxide Nanoparticles by Simple Beaker Chemistry

Abstract

A facile approach to synthesize ‘colloidal’ ZnO nanoparticles with control over the size is presented here. All the synthesis was carried out at room temperature and simple beaker chemistry was utilized. The approach leads to slow growth of colloidal nanoparticles with saving of energy because no heating (room temperature) is required during reaction. To verify the nucleation and growth of the nanoparticles, time dependent UV–Vis absorption spectroscopy has been studied and found that growth of nanoparticles start within minute. Transmission electron microscopy and UV‐Vis absorption spectroscopy concludes that as reaction time increases particle size get larger and varies from 3–20 nm for 1 hour reaction time to 6 hour reaction time. XRD pattern of the ZnO nanoparticles shows a wurtzite crystalline nature which is supported by selected area electron diffraction measurement (SEAD), SEAD also confirms the polycrystalline nature of the ZnO nanoparticles. Photoluminescence of the colloidal solution of the ZnO particle show an excitonic band at 377 nm.