Sol-gel preparation and enhanced photocatalytic performance of Cu-doped ZnO nanoparticles

► Cu-doped ZnO nanoparticles were prepared by a sol-gel method for the first time. ► Cu-doped ZnO nanoparticles exhibited enhanced photocatalytic performance. ► The enhanced charge carrier separation and increased surface hydroxyl groups contributed to the enhanced photocatalytic activity. ► This research could provide a feasible route for organic wastewater treatment.