Highly dispersed Co/Fe bimetal in carbonaceous cages as heterogeneous Fenton nanocatalysts for enhanced sulfamethoxazole degradation

A self-assembly strategy was presented for the synthesis of highly dispersed Co/Fe bimetallic carbon cages (CoFe50@C) through thermal morphology-controlled transformation of Fe doping dual metal-organic frameworks (MOFs). Taking advantage of the well dispersibility, synergetic effects between Fe and Co species, and enhanced graphitization degree of carbon, CoFe50@C exhibited a high removal efficiency of 98% in 180 min for sulfamethoxazole (SMX). The synergistic effect between Co and Fe species played an important role in promoting the reduction of Co(III) to Co(II) and the adsorption of H 2 O 2 molecules, thus enhancing the generation of hydroxyl radicals (HO•), which had been demonstrated by density functional theory (DFT) calculations. Meanwhile, the graphitized carbon cages could prevent the loss of bimetallic active component and promote the electron transfer during catalytic reaction. This work provides a new type of highly dispersed Co/Fe bimetal carbon cages as heterogeneous Fenton nanocatalyst for the degradation of organic contaminants. • Highly dispersed CoFe50@C was fabricated through pyrolysis of Fe doped ZIF-8@ZIF-67. • CoFe50@C exhibited a high Fenton catalytic performance for SMX degradation. • DFT demonstrated bimetal CoFe50@C enhanced H 2 O 2 adsorption for HO• formation. • The synergistic effect between Co and Fe improved the HO• generation.