Mechanochemical Synthesis of Microscale Carbon-Modified\nFe/Cu Bimetallic Particles for Perchloroethylene Degradation

Extensive studies have shown that\niron-based bimetallic particles\ncan be used for the degradation of chlorinated hydrocarbons, but their\nrelatively low electron transfer efficiency and high preparation cost\nlimit their application. In this study, activated carbon (AC)-loaded\nbimetallic particles (Cu–Fe/AC) were prepared in one step by\nball-milling microscale zerovalent iron (mZVI), CuSO<sub>4</sub>,\nand AC particles, which had a low cost and high perchloroethylene\n(PCE) degradation efficiency (>85% was degraded within 12 h at\npH\n6–8 with an initial concentration of 10 mg/L). Mechanism explorations\nshowed that 0.1% of AC (mass ratio) loading could significantly weaken\nthe hydrogen evolution reaction and improve the electron efficiency\nof PCE degradation by Cu–Fe bimetallic particles. Increasing\nthe AC loading (0.1–1%) did not always lead to higher degradation\nefficiency of PCE, and when AC loading exceeded 0.5%, the AC layer\nbecame loose and the continuity decreased, hindering electron transfer\nto PCE. The degradation of PCE and its dechlorination products by\nCu–Fe/AC particles mainly relied on the absorbed H·(H·<sub>abs</sub>), while the contribution of direct electron transfer gradually\nincreased with increasing loading of AC. In addition, Cu–Fe/AC\nparticles showed better electrochemical properties and passivation\nresistance than unloaded bimetallic particles, suggesting a long duration\nwhen used for pollutant degradation. Overall, the Cu–Fe/AC\nparticles prepared in this study demonstrated a high potential for\nremediating groundwater contaminated with halogenated hydrocarbons.