Magnetically separable and recyclable ZnFe2O4 nanoparticles as an effective activator in resorcinol-formaldehyde resins-based photocatalysis-self-Fenton system

Non-homogeneous photocatalysis-self-Fenton technology presents an effective strategy for efficient photocatalytic degradation of pollutants, circumventing the issues of extensive contamination of water resources by free iron ions and reducing safety risks and cost issues associated with the generation of hydrogen peroxide (H2O2). In the photocatalysis-self-Fenton reaction, the activation efficiency of H2O2 determines the capacity for photocatalytic degradation and mineralization of pollutants. Consequently, this study adopted ZnFe2O4 (ZFO) as an efficient, magnetically recoverable H2O2 activator, successfully coupling it with resorcinol–formaldehyde (RF) resin to construct a photocatalysis-self-Fenton system, thereby achieving degradation of tetracycline (TC) under visible light. The experimental results revealed that apparent rate constant (kapp) for the RF/ZFO photocatalysis-self-Fenton system is 22.997 times higher than that of the Fenton system and 1.156 times higher than that of the photo-Fenton system. Under visible light, the RF resin can generate H2O2 in situ and is subsequently activated by ZFO, resulting in a highly oxidized hydroxyl radical (OH), attacking contaminants. This study presents new insights into the construction of efficient heterogeneous radiofrequency resin photocatalysis-self-Fenton degradation system and provides new solutions for efficient and environmentally friendly wastewater treatment.