Group-III–doped ZnO nanorods via aqueous chemical growth for enhanced photocatalytic activity

Rising anthropogenic contamination of water supplies challenges access to clean water and limits the efficacy of conventional treatment methods. Here, we report a rapid microwave-assisted synthesis of undoped and 1 at.% group-III (Al, Ga, In)-doped ZnO nanorods grown on glass substrates, followed by annealing at 550 °C. Field-emission scanning electron microscopy shows well-defined hexagonal nanorods for all samples, while X-ray diffraction confirms a hexagonal wurtzite structure with strong preferential orientation maintained after doping. Energy-dispersive X-ray spectroscopy verifies successful incorporation of Al, Ga and In into the ZnO lattice. Optical characterization reveals dopant-dependent modifications to the electronic structure and enhanced visible-light absorption attributable to defect-related states. Photocatalytic testing under solar irradiation for phenol degradation indicates markedly improved activity for the doped nanorods; we attribute this enhancement to the introduction of shallow and deep trap levels that suppress charge-carrier recombination and promote charge separation. Among the materials studied, In-doped ZnO nanorods exhibit the highest photocatalytic performance, highlighting their potential for solar-driven water purification applications.