Promotion of Fe3+/Fe2+ cycling by a novel MnxOy-loaded iron-tantalum-based catalyst for efficient persulfate activation: New insights into pollutant degradation via radical and non-radical pathways

A novel core-shell heterojunction photocatalyst Ta 3 N 5 @FeTaO 4 /Mn x O y was designed for efficient persulfate activation to enhance the photocatalytic performance. Ta 3 N 5 @FeTaO 4 /Mn x O y was synthesized using a two-step impregnation-calcination method, and tetracycline was selected as the model pollutant. The results indicated that the tetracycline degradation by Ta 3 N 5 @FeTaO 4 /Mn x O y was 3.79 and 13.42 times faster than those by Ta 3 N 5 @FeTaO 4 and Ta 3 N 5 , respectively. Pollutant degradation via radicals (·OH, SO 4 · − and O 2 · − ) and non-radicals (Fe(IV) and 1 O 2 ) was verified by probe tests, quenching experiments, and EPR analysis. The homologous growth heterojunction promoted the separation of charge carriers owing to the matched structure and seamless interface between Ta 3 N 5 and FeTaO 4 . The loaded Mn x O y enhanced persulfate adsorption and facilitated Fe 3+ /Fe 2+ cycling, consequently improving persulfate activation and the photocatalytic degradation of pollutants. This study reveals the often-overlooked role of iron-based catalysts to generate a wider range of reactive species, offering a new perspective to design Fenton-like photocatalytic materials.