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. [Display omitted] •Novel ternary Cu0-coupled core-shell Fe0/C nanoparticles catalysts were synthesized.•The addition of secondary metals boosts the electron transfer of Fe0.•Functional groups and conductivity of carbon layer enhance catalytic performance.•Degradation pathway of sulfathiazole was speculated by HPLC determination and DFT calculation.