Abstract: ZnFe2O4, a visible-light-responsive photocatalyst, exhibits significant potential for organic wastewater treatment due to its low environmental toxicity and magnetic recyclability. However, the rapid recombination of photogenerated electron-hole pairs in pure ZnFe2O4 severely limits its photocatalytic activity. To address this issue, ZnFe2O4/MXene photocatalysts were developed via a combined hydrothermal and room-temperature electrostatic adsorption approach. Additionally, the photocatalytic efficiency of ZnFe2O4 under visible light was enhanced through the morphology control of ZnFe2O4 (microrod, hollow microsphere, Archimedean polyhedron, “popcorn” sphere, nanoparticle) and the synergistic effect of MXene. The high conductivity of MXene improved charge transfer efficiency and facilitated the separation of photogenerated carriers. When ZnFe2O4 was synthesized as an Archimedean polyhedron and MXene dosage was 10% of ZnFe2O4, the optimized ZnFe2O4/MXene photocatalyst achieved a methylene blue (MB) degradation efficiency of 96.9% within 20 minutes, which was 2.1 and 3.0 times higher than that of ZnFe2O4 and MXene, respectively. Moreover, the degradation efficiency of MB remained over 90.0% after five cycles. The degradation mechanism of MB by ZnFe2O4/MXene was investigated using valence band spectrum of X-ray photoelectron spectroscopy and active species capture experiments. The results indicated that ?O2? served as the primary active species, while ?OH and h? played secondary roles in MB degradation.

Key words: Visible-light photocatalyst, ZnFe₂O₄, MXene, Methylene blue, Magnetic