Reasonably constructing BiVO4/CoNiFe-LDH S-scheme heterojunction with fast interface charge transfer for efficient photodegradation of tetracycline

Developing efficaciously S-scheme heterojunction with fast interface charge transfer is of significant importance for antibiotics eradication. Herein, an innovative BiVO₄/CoNiFe-LDH S-scheme heterojunction was strategically designed and constructed by tightly anchoring BiVO₄ microrods onto the surfaces of CoNiFe-LDH microflowers, and its degradation performance was assessed via eradicating tetracycline under visible light irradiation. Unsurprisingly, the optimal BiVO₄/CoNiFe-LDH heterojunction acquired the maximum apparent rate constant of up to 0.0120 min⁻¹ for tetracycline removal, which was approximately 10.0 and 2.0 times more fast than those of sole CoNiFe-LDH (0.0012 min⁻¹) and BiVO₄ (0.0061 min⁻¹), separately. The significantly boosted photodegradation activity was benefited from the creation of S-scheme heterojunction at the interface between CoNiFe-LDH and BiVO₄, considerably expediting the charge separation and maintaining the powerful redox capacity under the force of established internal electric field. Furthermore, reactive species substantiation tests corroborated that •O₂^– and h⁺ were greatly contributed to tetracycline degradation. In the end, the possible degradation pathways and mechanism of tetracycline were also elucidated. This work affords new insights and perspectives on the fabrication of high-efficiency S-scheme heterojunction with fast interface charge migration for antibiotic removal.