Fabrication And Properties Of Fe₂O₃ Arrays On Stainless Steel Substrate

As an important semiconductor, nanostructured Fe2O3 exhibits excellent performances in environmental protection, gas sensing, energy storage and conversion, and so forth, due to its unique physical and chemical properties. In this dissertation, Fe2O3 hierarchical arrays and Fe2O3 nanorod arrays have been prepared by in-situ hydrothermal chemical oxidation method and hydrothermal chemical deposition approach, respectively. Their catalytic and wettability performances have been investigated. The main points are summarized as follows:1. Hierarchical array catalysts with micro/nano structures on substrates not only inherit high reactivity from large surface area and suitable interface, but intensify mass transfer through shortening the diffusion paths of both reactants and products for high catalytic efficiency. Herein, we first demonstrate fabrication of Fe2O3 hierarchical arrays grown on stainless-steel substrates via in-situ hydrothermal chemical oxidation followed by heat treatment in N2 atmosphere. As a Fenton-like catalyst, Fe2O3 hierarchical arrays exhibit excellent catalytic activity and life cycle performance for methylene blue (MB) degradation in aqueous solution in the presence of H2O2. The Fe2O3 catalyst with unique hierarchical structures, efficient transport channels and excellent wettability, effectively activate H2O2 to generate large quantity of ·OH radicals and highly promote reaction kinetics between MB and ·OH radicals. Immobilization of hierarchical array catalysts on stainless-steel can prevent particle agglomeration and facilitate the recovery of catalyst, which is expected promising applications in wastewater remediation.2. Wettability performances of Fe2O3 hierarchical array films and Fe2O3 nanorod array films have been investigated. The results showed that, compared with Fe2O3 nanorod array films, Fe2O3 hierarchical array films exhibit better wettability performance. The contact angle of Fe2O3 hierarchical array films becomes smaller with the surface free energy increasing due to change of polar force. The contact angle of Fe2O3 nanorod array films becomes larger with the surface free energy decreasing due to change of dispersion force. And liquid holdups of Fe2O3 hierarchical array films and Fe2O3 nanorod array films are 43.51 mg/cm2 and 35.05 mg/cm2, respectively. The relationship between wettability and liquid holdup of the array films grown on stainless steel substrates is studied, which will provide experimental basis for the subsequent application in a packed column.