Efficient photocatalytic remediation of persistent organic pollutants using magnetically recoverable spinel manganese ferrite nanoparticles supported on activated carbon

•MFO dispersed on AC were prepared by simple gel combustion from low-cost precursors.•Paramagnetic MFC can be recovered from solution by applying an external magnet.•AC supports limited particle agglomeration and enhanced photocatalytic activity of MFO.•MFC (Eg = 2.02 eV) efficiently removed ≥90 % of PCP within 2.5 h under mild conditions.•Study on active species and degradation mechanism showed crucial roles of e¯ and •OH. Magnetically recoverable spinel manganese ferrite (MFO) nanoparticles (NPs) supported on activated carbon (AC) (MFC), a promising photocatalyst, were prepared by simple and cost-effective gel combustion. AC supports prevented particle agglomeration and functioned as electron acceptors to promote charge separation on MFO. MFC samples demonstrated significant surface area, paramagnetic characteristics, and visible-light absorption bandgap of 2.02 eV. Pentachlorophenol (PCP) photodegradation using MFC showed degradation efficiency of at least 90 % after 150 min at pH 6.0 with the catalyst dose and PCP concentration of no more than 10 mg.L−1 and 9.0 ppm, respectively. MFC exhibited durability and recyclability with approximately 4 % decrease in degradation efficiency after five reuses while maintaining its material structure. The crucial roles of photo-generated electrons and hydroxyl radicals related to dechlorination and hydroxylation during PCP photodegradation were also highlighted in active species investigations with appropriate scavengers. Subsequently, a plausible PCP photodegradation mechanism with intermediates was proposed. The MnFe2O4 nanoparticles with cubic spinel structure dispersed on activated carbon were prepared by the gel-combustion method from low-cost precursors and used as a magnetically recoverable photocatalyst for the degradation of persistent organic pollutants in wastewater. [Display omitted]