Peroxydisulfate-enhanced photocatalytic degradation of Tetracycline using NiO/α-Fe2O3-C derived from hierarchical NiFe Prussian blue analogue via seed-mediated growth

Antibiotics in the environment pose ecological risks and promote drug resistance. Heterostructure photocatalysts offer a solution but are often hindered by charge carrier recombination. Integrating photocatalysis with peroxydisulfate (PDS) activation mitigates this issue by enhancing charge separation. Herein, we report for the first time the synthesis of a NiO/α-Fe₂O₃-C p–n heterojunction via an epitaxial hierarchical NiFe Prussian blue analogue via seed-mediated growth template, followed by thermal oxidation, enabling efficient visible-light-driven PDS activation for tetracycline degradation. This PBA-derived approach allows precise control over composition and interface structure, resulting in superior ROS generation compared to conventional heterojunction fabrication methods. The catalyst achieved 87.67 % tetracycline degradation (2 mg/30 mL catalyst, 2.5 mM/L PDS, pH 5.5, 150 min) with a pseudo-first-order rate constant of 0.025 min⁻¹, attributed to the synergistic production of O₂^•−, h⁺, SO₄^•− and ^•OH. Notably, the NiO/α-Fe₂O₃-C exhibited remarkable recyclability and reusability, maintaining high degradation efficiency even after six consecutive cycles. This work introduces a novel, scalable PBA-templated strategy for constructing high-performance heterojunction photocatalysts, offering a sustainable pathway for industrial wastewater remediation.