The book reviews the fundamentals of advanced oxidation processes (AOPs) technologies to degrade hazardous organics via photocatalysis of 1-dimensional zinc-oxide (ZnO). One-dimensional ZnO nanorods (ZnO-NRs) have been of utmost interest due to their high surface area, efficient charge transport, and superior photosensitivity. These features make ZnO-based nanorods exciting candidates for applications in photocatalysis. Even though photocatalysis using bare ZnO nanorods is useful in pollutant remediation, several drawbacks such as high recombination of photo−excited charge carriers and ineffective operation of sunlight make it less effective. This book thus presents a review of the current modification strategies carried out to increase the ZnO nanorods photoactivity, such as enhancing the photocatalytic activity of ZnO through modification of its electronic and optical properties, doping metal/nonmetal atoms, depositing noble metals, constructing heterojunctions, and coupling carbon materials. This book provides invaluable insights for researchers, engineers, and policymakers seeking sustainable solutions for pollutant degradation. Furthermore, the discussion on future directions illuminates the potential of ZnO nanorods as a promising photoactive material, fostering continued innovation and progress in the field.