Enhanced Photocatalytic Degradation of Organic Dye via Hydrothermal Synthesized Lithium‐Doped Zinc Oxide

ABSTRACT Photocatalytic technology is a promising strategy for wastewater treatment due to its minimal secondary pollution and high solar energy utilization efficiency. However, the application of photocatalysts like zinc oxide (ZnO) is hindered by the wide bandgap and rapid recombination of electron–hole pairs. To address this issue, we developed Li‐doped ZnO catalysts via a simple hydrothermal method to tailor its electronic structure and enhance photocatalytic performance. The as‐prepared catalysts were characterized by SEM, XRD, XPS, and DRS. Results revealed that Li + ions were successfully incorporated into the ZnO crystal lattice, which effectively narrowed the bandgap and improved charge separation. Photocatalytic evaluation demonstrated that 1% Li‐doped ZnO catalyst achieved a remarkable rhodamine B (RhB) degradation efficiency of 93.30% within 25 min under light irradiation, significantly outperforming pure ZnO (40.73%). Notably, the apparent rate constant of the optimal catalyst was calculated to be 0.1041 min −1 , which is approximately four times higher than that of pure ZnO (0.0216 min −1 ). Radical trapping experiments and mechanism analysis revealed that h + , •O 2 − , OH, and 1 O 2 all contributed to the degradation, with the enhanced activity attributed to the Li‐induced modification of the energy band structure and photoelectric properties. This work provides a facile doping strategy to engineer efficient ZnO‐based photocatalysts for environmental remediation.