Reconstruction of The Surface Bi3+ Oxide Layer on Bi2O2CO3: Facilitating Electron Transfer for Enhanced Photocatalytic Degradation Performance of Antibiotics in Water

The advancement and meticulous design of functional photocatalysts exhibiting exceptional photocatalytic redox activity represent a pivotal approach to mitigating the dual challenges of environmental pollution and energy scarcity. In this study, we elucidate the construction of a Bi₂O₂CO₃ catalytic system capable of inhibiting oxidative electron transfer through the attenuation of homogeneous Bi⁰ particle formation, achieved through the judicious modulation of solvent ratios. This innovative architecture possesses a distinctive active site and enhances interfacial Bi-O electron transfer pathways via exposure to oxidized Bi³⁺. Upon photoexcitation, the Bi₂O₂CO₃ catalytic system undergoes structural distortions in its excited state that facilitate forbidden radiative relaxation, thereby fostering long-lived charge separation states. Remarkable catalytic activity was demonstrated in the remediation of pollutants, encompassing auto-oxidation and the catalytic degradation of superoxide radicals (•O₂^-) and holes (h⁺). Notably, the effective degradation of tetracycline hydrochloride (TCH) in aqueous media reached an impressive 86% under simulated visible light irradiation, accompanied by a reaction rate constant 3.08 times superior to that of the 5-Bi/Bi₂O₂CO₃ counterpart. Theoretical analyses revealed that the oxidized state of Bi₂O₂CO₃ exhibits a crystal structure with significant electron trapping capability, undergoing pronounced apparent relaxation phenomena on its surface while demonstrating an enhanced adsorption affinity for H₂O and O₂. The potential degradation mechanisms were rigorously investigated through High-performance liquid chromatography (HPLC-MS), elucidating the photodegradation pathways and intermediates of TC. This work may serve as a distinct paradigm for the rational design of novel photocatalysts aimed at fostering sustainable environmental remediation and advancing energy innovation.