Institute of Physical Chemistry, Justus-Liebig-University Giessen, Heinrich-Buff Ring 58, Giessen 35392, Germany.
Small. 2011 Feb 7;7(3):407-14. doi: 10.1002/smll.201001333. Epub 2010 Dec 23.
Herein is reported the synthesis of ordered mesoporous α-Fe(2)O(3) thin films produced through coassembly strategies using a poly(ethylene-co-butylene)-block-poly(ethylene oxide) diblock copolymer as the structure-directing agent and hydrated ferric nitrate as the molecular precursor. The sol-gel derived α-Fe(2)O(3) materials are highly crystalline after removal of the organic template and the nanoscale porosity can be retained up to annealing temperatures of 600 °C. While this paper focuses on the characterization of these materials using various state-of-the-art techniques, including grazing-incidence small-angle X-ray scattering, time-of-flight secondary ion mass spectrometry, X-ray photoelectron spectroscopy, and UV-vis and Raman spectroscopy, the electrochemical properties are also examined and it is demonstrated that mesoporous α-Fe(2)O(3) thin-film electrodes not only exhibit enhanced lithium-ion storage capabilities compared to bulk materials but also show excellent cycling stabilities by suppressing the irreversible phase transformations that are observed in microcrystalline α-Fe(2)O(3).
本文报道了通过共组装策略合成有序介孔α-Fe(2)O(3)薄膜的方法,该策略使用了一种聚(乙烯-co-丁烯)-嵌段-聚(氧化乙烯)两亲性嵌段共聚物作为结构导向剂,水合硝酸铁作为分子前体。溶胶-凝胶法衍生的α-Fe(2)O(3)材料在除去有机模板后具有很高的结晶度,纳米级孔隙率可保持到 600°C 的退火温度。虽然本文的重点是使用各种最先进的技术对这些材料进行表征,包括掠入射小角 X 射线散射、飞行时间二次离子质谱、X 射线光电子能谱以及紫外-可见和拉曼光谱,但也研究了它们的电化学性能,并证明介孔α-Fe(2)O(3)薄膜电极不仅表现出增强的锂离子存储能力,与体材料相比,而且通过抑制在微晶晶粒α-Fe(2)O(3)中观察到的不可逆相变,表现出优异的循环稳定性。