A review on improving the efficiency of photocatalytic water decontamination using ZnO nanorods

Advanced oxidation processes (AOPs) are technologies for the remośśśval of organic contaminants in water. One of the main effective AOP technologies to degrade hazardous organics is photocatalysis. ZnO has been well-known as a significant photocatalyst material. 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. In this work, we present 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. Finally, the relevance of the results and future directions of ZnO nanorods as a photoactive material was discussed. Graphical abstract Highlights ZnO nanorods show high surface area, efficient charge transport, and superior photosensitivity. Photocatalysis using bare ZnO nanorods is useful in pollutant remediation. ZnO nanorods are improved through the modification of their electronic and optical properties.