ZnO Nanoparticles for Photocatalytic Methyl Orange Degradation: Hydrothermal Synthesis, Characterization, and Optimization

This study investigates the production of zinc oxide nanoparticles (ZnO NPs) utilizing an efficient and surfactant-free hydrothermal method for use as a photocatalytic agent in the purification of organic polluted water. The structural features, optical properties and photocatalytic performance of ZnO NPs have been investigated. XRD, SEM, HR-TEM, FTIR and UV–vis absorption spectroscopy were used as analytical and characterization techniques. The ZnO NPs prepared with hexagonal structure and interesting applied properties was obtained by adjusting the processing time at a low treatment temperature of 75 °C. The crystallite size and energy band gap are reaction time-dependent, which in turn affects the photocatalytic performance. ZnO NPs under UV irradiation show an efficiency of 93% in the photocatalytic decomposition of methyl orange (MO) dye. The value of ZnO NPs bandgap (3.38 eV) is suitable for allowing UV light absorption and rapid generation of charge carriers; creating photooxidation reactions for decomposing the organic dye.