Cu–Fe–FeC3@nitrogen-doped biochar microsphere catalyst derived from CuFe2O4@chitosan for the efficient removal of amoxicillin through the heterogeneous electro-Fenton process

The heterogeneous electro-Fenton (hetero-EF) technology is an attractive but challenging method used to degrade organic pollutants. The development of a catalysts for the stable and efficient degradation of pollutants under neutral conditions remains a challenging task. In this study, a microsphere catalyst consisting of magnetic Cu–Fe–FeC3 on nitrogen-doped biochar (Cu–Fe–Fe3[email protected]) was prepared using chitosan as the carrier material in a two-step process. A hetero-EF system using Cu–Fe–Fe3[email protected] as the catalyst was constructed to efficiently degrade amoxicillin. The catalyst exhibited a wide pH application range, a good stability, and a low metal ion leaching. The main reasons behind the remarkable catalytic performance and excellent stability of the Cu–Fe–Fe3[email protected] catalyst are: (i) The presence of a core–shell structure, in which Cu–Fe bimetallic particles are wrapped in the structure of biomass carbon to slow down the loss of the metal active component in the catalyst and maintain its stability; (ii) The uniform dispersion of nanoparticles on the surface of the Cu–Fe–Fe3[email protected] catalyst, N-doped carbon, and the combined effect of Cu and Fe, which are beneficial to improve the charge transfer efficiency and regulate the electronic structure, which in turns improve the activity of the catalyst. This work demonstrates that the efficient degradation of pollutants under neutral conditions can be achieved and provides useful information for the design and synthesis of efficient and stable catalysts in hetero-EF reaction systems.