Concurrent elimination of antibiotics and resistant bacteria for effective antibiotic resistance genes control: a photocatalytic strategy enabled by ion-exchange-confined strong metal-support interaction.

The rapid recombination of photogenerated electron-hole pairs serves as the primary kinetic bottleneck limiting the photocatalytic efficiency of layered double hydroxides (LDHs). The inherently sluggish charge carrier migration and insufficient surface reaction sites of LDHs result in extensive recombination of photogenerated carriers before they reach the surface to participate in reactions. Consequently, an insufficient amount of reactive species is generated to effectively address the issue of antimicrobial resistance in aquatic environments. To address this, PLDO1 was developed, a catalyst featuring atomically dispersed Pt anchored on ZnTi-layered double oxide (ZnTi-LDO), synthesized via a site-selective ion-exchange and spatial confinement pyrolysis strategy. The ZnTi-LDO material is rich in oxygen vacancies, endowing it with a strong electron capture capability. This strong metal-support interaction (SMSI) consequently diverts the direction of electron flow, shifting it from the metal toward the support. Experimental and theoretical analyses demonstrate that single-atom Pt optimizes the band structure while simultaneously enhancing the generation of singlet oxygen (1O2) as the dominant reactive species. The optimized PLDO1 catalyst achieves 91.73 ± 0.56% tetracycline (TC) degradation under visible light, with 2.33-fold higher kinetics than ZnTi-LDO. Importantly, the system achieved near-complete elimination (>99%) of both ARB and associated ARGs within 150 min, demonstrating its high efficacy in the concurrent removal of chemical pollutants and genetic determinants of resistance. This electronic-structure engineering via atomic-scale SMSI structure provides a universal design strategy for high performance layered photocatalysts in pharmaceutical pollutant remediation.