Novel ternary Cu-coupled core-shell Fe/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 (Fe/C@Cu) was synthesized for the degradation of sulfathiazole (STZ). Fe/C@Cu catalysts exhibited excellent reusability and stability owing to the inner tailored Fe with persistent activity. The connection between Fe and Cu elements in the Fe/C-3@Cu catalyst prepared with iron citrate as iron source exhibited a tighter contact than the catalysts prepared with FeSO·7HO and iron(II) oxalate as iron sources. Especially, unique core-shell structure of Fe/C-3@Cu 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 Fe/C@Cu. Carbon layer with remarkable conductivity allowed electrons from Fe transferred freely to the Cu. The electron-rich Cu releases electrons, facilitating the degradation of STZ. Furthermore, the high potential difference between cathode (C and Cu) and anode (Fe) accelerate the corrosion of Fe. Importantly, Fe/C@Cu catalysts exhibited excellent catalytic performance for sulfathiazole degradation in landfill leachate effluent. Results presented provide a new strategy for treatment of chemical wastes.