Zinc oxide (ZnO) has garnered significant attention for its photocatalytic properties, making it a promising material for water purification. Due to its wide bandgap, high photosensitivity, transparency, and thermal stability, ZnO is well-suited for applications in environmental remediation. However, its efficiency in photocatalysis is hindered by a high electron-hole recombination rate, which limits its catalytic performance. To address this issue, researchers have explored various strategies, including doping ZnO with transition metals, forming composites, and developing nanostructures to enhance its photocatalytic activity. Doping ZnO with metals like iron, copper, and cerium or non-metals like nitrogen can introduce new energy levels within the material's bandgap, improving charge separation and reducing electron-hole recombination. Compositing ZnO with materials like polypyrrole (PPy) or graphene oxide (GO) has also proven effective in boosting electron mobility and increasing the number of active sites for pollutant degradation. Additionally, nanostructuring ZnO into nanoparticles, nanorods, or nanowires increases its surface area and light absorption capabilities, making it more efficient in photocatalytic reactions. In his research, Dr. Satpal highlights how these modifications enhance ZnO's ability to degrade organic pollutants, such as dyes found in textile wastewater, and to remove heavy metals like lead and arsenic. ZnO-based photocatalysts have also shown effectiveness in disinfecting water by inactivating harmful microorganisms. By optimizing ZnO through doping, composites, and nanostructuring, this research provides valuable insights into the development of efficient, sustainable photocatalysts for water purification. These advancements offer a promising solution to global clean water challenges, especially in regions with limited access to safe drinking water.
