Carbon-coated iron nanoparticles were synthesized by a carbon arc discharge method using electrodes made of iron and graphite powder. The amorphous carbon layer of the carbon-coated iron nanoparticles was treated by a 30% H2O2 aqueous solution. Adsorption of the carbon-coated iron particles for heavy metal ions, such as Cr, Ni, Cd, Pb, Co and Mn, was studied. Results showed that carboxyl and hydroxyl groups were formed on the surface of the amorphous carbon layer after the treatment by hydrogen peroxide. In a strong alkaline medium, the hydroxyl and carboxyl groups increased the electrostatic attraction, and the adsorption performance of the treated carbon-coated iron particles for heavy metal ions was improved. The removal efficiencies for Cr, Ni, Cd, Pb, Co and Mn by the treated carbon-coated iron nanoparticles were all over 90% in a pH range of 8-10 and their adsorption capacity is much higher than that of activated carbons.%采用氩电弧等离子体法制备炭包铁纳米粒子,并用体积分数30％的H2O2氧化其外层非晶态类石墨碳层,研究炭包铁纳米粒子对水溶液中Cr、Ni 、Cd 、Pb、Co和Mn等金属离子的吸附和分离特性.结果表明,炭包铁非晶炭层的特殊结构可通过双氧水氧化处理使其表面产生羧基和羟基.在强碱性介质下,羟基和羧基强化了纳米颗粒表面的静电作用,提高了炭包铁对金属离子的吸附性能.当pH值为8.0 ～10.0时,炭包铁纳米粒子对Cr、Ni、Cd、Pb、Co和Mn的吸附率均超过90％,对重金属离子的吸附能力明显高于活性炭.
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