Controlled Carbothermal Shock Fabrication of Unique Double-Layer Core-Shell Fe@FeC@Graphite as an Enhanced, Efficient, and Stable Fenton-Like Catalyst.

Iron-carbon materials have emerged as promising heterogeneous Fenton-like catalysts for the removal of emerging organic contaminants. However, their practical applications are substantially hindered by complex preparation procedures and irreversible deactivation of iron centers. Herein, a novel double-layer core-shell catalyst Fe@FeC@Graphite (Fe-CTS-3000) is one-step synthesized by a high-temperature carbothermal shock (CTS) strategy. Fe-CTS-3000 features a unique core-shell structure: the uniform nanoscale zero-valent iron (nZVI) core, the complete and homogeneous FeC interlayer, and the highly defective graphitic carbon shell. With a distinctive structure, Fe-CTS-3000 exhibits exceptional catalytic performance, achieving 99.0% tetracycline (TC) removal efficiency and 69.2% mineralization rate, and remarkable stability with higher than 95.8% removal efficiency over 5 cycles in the Fe-CTS-3000/HO Fenton-like system. The defective graphite shell enhances TC adsorption, and the nZVI core effectively activates HO and further promote the generation of radicals and nonradicals for TC degradation. The complete FeC interlayer facilitates electron transfer and protects the nZVI core from leakage deactivation. Both radical pathways (•OH, •O ) and non-radical pathways (O, electron transfer) contributed to the highly efficient degradation of TC. The study provides a rapid and controllable method for synthesizing highly efficient iron-carbon catalysts from renewable biomass for the Fenton-like degradation of persistent organic pollutants.