Unlocking Synergistic Photo-Fenton Catalysis with Magnetic SrFe<sub>12</sub>O<sub>19</sub>/g-C<sub>3</sub>N<sub>4</sub> Heterojunction for Sustainable Oxytetracycline Degradation: Mechanisms and Applications

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 ass...

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Bibliographic Details
Main Authors: Song Cui, Yaocong Liu, Xiaolong Dong, Xiaohu Fan
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/15/11/833
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Summary: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<sub>12</sub>O<sub>19</sub>/g-C<sub>3</sub>N<sub>4</sub> 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<sup>−</sup>)–hole (h<sup>+</sup>) 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<sup>−1</sup>, which are 9.1 times higher than those of SrFe<sub>12</sub>O<sub>19</sub> (0.0043 min<sup>−1</sup>) and 4.2 times higher than those of g-C<sub>3</sub>N<sub>4</sub> (0.0094 min<sup>−1</sup>). The effectively separated e<sup>−</sup> play three critical roles: (i) directly activating H<sub>2</sub>O<sub>2</sub> to generate ·OH radicals, (ii) promoting the redox cycling of Fe<sup>2+</sup>/Fe<sup>3+</sup> ions, and (iii) reducing dissolved oxygen to form ·O<sub>2</sub><sup>−</sup> species. Concurrently, h<sup>+</sup> 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.
ISSN:2079-4991