Development of Self-Assembled 3D Fe _x O _y Micro/Nano Materials for Application in Hexachlorobenzene Degradation

Self-assembled three dimensional (3D) hierarchical, flower-like iron oxide micro/nano materials, including pure Fe₃O₄, α-Fe₂O₃/Fe₃O₄ composite and pure α-Fe₂O₃, were developed to degrade hexachlorobenzene (HCB) at 300 °C. It was found that pure Fe₃O₄ exhibited the highest activity with the reaction rate constant at 0.959 min⁻¹. Identified degradation products with lower chlorinated benzenes suggest a stepwise hydrodechlorination was occurring for the degradation of HCB on the synthesized Fe₃O₄. The characterization of the synthesized iron oxides after reaction indicates the Fe₃O₄ phase was partially transformed into α-Fe₂O₃ phase and in return accelerated progress of hydrodechlorination of HCB. The superior performance of as-prepared Fe₃O₄ could be attributed to its structural feature such as surface area and pore structure, as well as its phase transformation during HCB degradation.