Enhanced Photocatalytic Wastewater Purification and Bacterial Elimination via Copper Ion Irradiation‐Induced Modification of BiOCl

ABSTRACT The BiOCl photocatalyst possesses a relatively weak inherent intrinsic electric field property, which significantly hampers the separation efficiency of photogenerated carriers and, consequently, limits the full exploitation of its application potential. Reliably addressing this issue stands as an outstanding challenge in the quest to improve the catalyst's activity. In this study, we utilized carrying‐energy copper ion beam irradiation to modify BiOCl, aiming to controllably bolster its intrinsic electric field. Through meticulous adjustment of the copper ion beam irradiation dosages, we achieved controlled local structural reconstructions in BiOCl. The reconstructions notably altered the surface potential gradient, thereby amplifying the efficacy of the intrinsic built‐in electric field, inhibiting the recombination of photogenerated carriers, and ultimately leading to remarkable improvements in photocatalytic performance. As a result, the irradiated‐BiOCl composite demonstrated a 3.5‐fold in RhB degradation rate compared to pristine BiOCl under light irradiation, accompanied by complete inactivation of E. coli within 15 min. The inspiration of copper ion beam irradiation engineering presents a scalable approach for advancing multifunctional photocatalysis in environmental remediation and public health applications.