Alloy-like Fe-Mn oxides with notable magnetic properties and catalytic performance for H2O2 activation: insights into electron effect and improved stability

The preparation of highly efficient and easily recoverable Fenton catalysts for removing refractory pollutants is challenging. Herein, a novel magnetic alloy-like oxide catalyst with abundant unsaturated centres and the low valence states was successfully designed by high-temperature solid phase modulation. The prepared material is characterized by its ability to inhibit the self-decomposition of the Fe-MOFs in water and overcome the recycling limitations of traditional catalysts. The effects of various synthesis parameters, including calcination temperature, on the catalytic properties of the MOF derivatives were investigated. The optimized FM800/H2O2 system exhibited remarkable catalytic performance, achieving 90 % degradation of the 20 mg/L tetracycline solution within 10 min and approximately 100 % degradation within 60 min. The material retained efficient degradation activity and reusability across a pH range of 5–11, with Mn leaching rates below 0.01 mg/L. Theoretical calculations demonstrated that bimetallation lowers the band gap between the d-band center and the Fermi energy level, facilitating low-valent metals generation and H2O2 activation. This study provides valuable insights into the design of high-performance multiphase catalysts and underscores the promising potential of stable MOFs derivatives in wastewater treatment.