The increasing levels of water pollution have created an urgent need for efficient and sustainable treatment technologies. Conventional methods often struggle to remove stable organic pollutants, leading to growing interest in photocatalysis, which utilizes semiconductor materials to generate reactive species for pollutant degradation. In this study, zinc oxide (ZnO) nanoparticles were synthesized using a chemical precipitation method and optimized to enhance their photocatalytic performance. The synthesized nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV–Visible spectroscopy to evaluate their structural and optical properties. Their photocatalytic activity was investigated through the degradation of methylene blue dye under ultraviolet (UV) irradiation in a batch photoreactor system. The effects of key operational parameters, including pH and initial dye concentration, were systematically examined to determine optimal conditions. The results demonstrated that ZnO nanoparticles exhibit strong photocatalytic activity under UV light, achieving a maximum degradation efficiency of 95% at pH 11 and an initial dye concentration of 20 mg/L. Kinetic analysis further confirmed that the use of imidazole and calcination at 400 °C significantly enhanced catalyst performance, enabling rapid degradation of organic pollutants. These findings highlight the potential of ZnO nanoparticles as an effective and economical solution for wastewater treatment. Moreover, optimization of synthesis and operational parameters contributes to reducing energy consumption and minimizing environmental impacts, supporting the development of more sustainable treatment processes. Objectives: The primary goal of this study is to investigate the influence of synthesis conditions on the properties of Zinc Oxide (ZnO) nanoparticles and to optimize these parameters for the efficient degradation of organic pollutants in wastewater. The objectives are as follows: 1. To establish a reliable chemical precipitation method for synthesizing ZnO nanoparticles using zinc acetate and imidazole as precursors. 2. To Characterize Structural and Morphological Properties, analyzing the crystallinity, surface morphology, and optical bandgap of the synthesized materials. 3. To Evaluate Photocatalytic Efficiency in Wastewater Treatment and quantifying the degradation kinetics of Methylene Blue under UV irradiation, determining the effectiveness of the nanoparticles in removing organic contaminants from aqueous solutions. 4. To Optimize the Synthesis for Sustainable Application and identifying the ideal parameter configuration that maximizes pollutant removal efficiency while minimizing thermal energy requirements and processing time.
