Carbon-nZVI nanocomposites for dechlorination of halogenated hydrocarbons

A family of hybrid nanocarbon/nanoiron composites has been developed with the aim to carry out simultaneous adsorption and dechlorination of chlorinated hydrocarbons from aqueous solutions. Several methodologies for the synthesis of these materials are evaluated in terms of their adsorption capacities and dechlorination activities. Detailed spectroscopic and microscopy studies indicate that the adsorption ability of the carbonaceous support is greatly improved after acid oxidization, attributed to the formation of oxygenated functional groups on their surfaces. When iron nanoparticles are incorporated on the composites, the materials show a much higher trichloroethylene (TCE) removal efficiency compared to bare metallic nanoiron particles or nanocarbon. It is proposed that in this hybrid nanomaterial system, the carbonaceous material serves as a highly efficient adsorbent and an effective support to immobilize iron nanoparticles simultaneously. Thermal programmed reduction studies suggest a strong support interaction with the nanoiron particles, which diminishes the possibility of agglomeration in solution and thus maintains their high reactivity for redox TCE dechlorination