Novel ternary Cu0-coupled core-shell Fe0/C nanoparticles micro-electrolysis system toward degradation of organic pollutants: Synergistic effects and removal mechanism

A ternary micro-electrolysis system consisting of carbon-coated metallic iron with Cu nanoparticles (Fe⁰/C@Cu⁰) was synthesized for the degradation of sulfathiazole (STZ). Fe⁰/C@Cu⁰ catalysts exhibited excellent reusability and stability owing to the inner tailored Fe⁰ with persistent activity. The connection between Fe and Cu elements in the Fe⁰/C-3@Cu⁰ catalyst prepared with iron citrate as iron source exhibited a tighter contact than the catalysts prepared with FeSO₄·7H₂O and iron(II) oxalate as iron sources. Especially, unique core-shell structure of Fe⁰/C-3@Cu⁰ catalyst is more conducive to promoting the degradation of STZ. A two-stage reaction with rapidly degradation followed by gradual degradation was revealed. The mechanism of STZ degradation could be explained by the synergistic effects of Fe⁰/C@Cu⁰. Carbon layer with remarkable conductivity allowed electrons from Fe⁰ transferred freely to the Cu⁰. The electron-rich Cu⁰ releases electrons, facilitating the degradation of STZ. Furthermore, the high potential difference between cathode (C and Cu⁰) and anode (Fe⁰) accelerate the corrosion of Fe⁰. Importantly, Fe⁰/C@Cu⁰ catalysts exhibited excellent catalytic performance for sulfathiazole degradation in landfill leachate effluent. Results presented provide a new strategy for treatment of chemical wastes.