(438d) Synthesis of Iron/Iron Oxide Core-Shell Nanoparticle and Its Application in Hydrogen Peroxide and Pollutant Degradation

Advanced oxidation technology has been widely used in the water remediation and toxic remnant degradation due to its high efficiency and simple procedures. In this process, H2O2, UV, and O3 were always employed as the reactive oxidants. The free radicals generated from the oxidants were reported to be very active when utilized in the decomposition of toxic compounds. Lots of extended work has been done on the Fenton reaction in the homogenous solution phase, while we focus on the heterogeneous Fenton reaction using Fe0/Fe2O3 core-shell nanoparticles and H2O2. The particles were synthesized in the aqueous phase by the oxidation of zero-valent iron nanoparticles (ZVIN), prepared by chemical reduction of ferrous chloride with sodium borohydride. Brunauer-Emmett-Teller (BET) nitrogen adsorption result showed that the particles had a high specific surface area (253 m2/g), which indicated the particles had the porous structure. The particle size (50-75 nm) and morphology were verified by dynamic light scattering (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The reaction between the particles and H2O2 at the neutral pH generated the hydroxyl radicals which removed the toxic organic chloride in the aqueous phase. The model compound trichloroethylene (TCE) were used to investigate the dechlorination. The kinetics of hydrogen peroxide degradation was developed based on a Fenton-like reaction mechanism. The core-shell nanoparticles were also immobilized in the polyacrylic acid (PAA) functionalized hydrophilic polyvinylidene fluoride (PVDF) microfiltration membrane pores by the ion exchange of carboxylic acid groups with ferrous irons. H2O2 degradation was investigated based on this functionalized membrane. The membrane based Fe0/Fe2O3 core-shell nanoparticles also showed the high reactivity in TCE dechlorination. The diffusion and reaction model in a single porous nanoparticle and in the membrane pores were also set up to predict the mass transfer laws of hydrogen peroxide.