Abstract
The widespread contamination of aquatic environments by tetracycline antibiotics (TCs) poses a substantial threat to public health and ecosystem stability. Although photo-Fenton processes have demonstrated remarkable efficacy in degrading TCs, their practical application is limited by challenges associated with catalyst recyclability. This study reports the development of a novel magnetic recoverable SrFe(12)O(19)/g-C(3)N(4) heterostructure photocatalyst synthesized via a facile one-step co-calcination method using industrial-grade precursors. Comprehensive characterization revealed that nitrogen defects and the formation of heterojunction structures significantly suppress electron (e(-))-hole (h(+)) pair recombination, thereby markedly enhancing catalytic activity. The optimized 7-SFO/CN composite removes over 90% of oxytetracycline (OTC) within 60 min, achieving degradation rate constants of 0.0393 min(-1), which are 9.1 times higher than those of SrFe(12)O(19) (0.0043 min(-1)) and 4.2 times higher than those of g-C(3)N(4) (0.0094 min(-1)). The effectively separated e(-) play three critical roles: (i) directly activating H(2)O(2) to generate ·OH radicals, (ii) promoting the redox cycling of Fe(2+)/Fe(3+) ions, and (iii) reducing dissolved oxygen to form ·O(2)(-) species. Concurrently, h(+) directly oxidize OTC molecules through surface-mediated reactions. Furthermore, the 7-SFO/CN composite exhibits exceptional operational stability and applicability, offering a transformative approach for scalable photocatalytic water treatment systems. This work provides an effective strategy for designing efficient and recoverable photocatalysts for environmental remediation.