表面缺陷α-Fe2O3(001)纳米片双活性位点类芬顿催化剂用于降解污染物
Surface-Electronic-State-Modulated, Single-Crystalline (001) α-Fe2O3 Nanosheets with Dual Reaction Sites for Efficient Fenton-Like Catalysis
作者单位E-mail
邱江源 广西民族大学化学化工学院, 南宁 530006  
肖碧源 广西民族大学化学化工学院, 南宁 530006  
覃方红 广西民族大学化学化工学院, 南宁 530006  
张美婷 广西民族大学化学化工学院, 南宁 530006  
万婷 湖北地质局第六支队, 孝感 432000  
刘锦萍 广西民族大学化学化工学院, 南宁 530006  
陈建华 广西大学环境与资源学院, 广西金属资源利用和环境保护中心, 广西有色金属和特色材料加工重点实验室, 南宁 530004 huangzaiyin@163.com 
黄在银 广西民族大学化学化工学院, 南宁 530006 jhchen@gxu.edu.cn 
摘要: 纯Fe2O3表面活性位点较少具有较低的催化活性限制了其在多相芬顿催化体系中的应用。通常采用元素掺杂、贵金属负载以及与其它化合物质复合等改性措施来提升催化活性,然而这些措施存在催化剂制备复杂,制备成本高以及催化剂的精细结构难以精准控制等问题。因此,本文提出在α-Fe2O3表面引入氧空位缺陷构筑双活性位点(Fe2+和氧空位)用于促进H2O2分解提高降解污染物降解效率。实验结果发现α-Fe2O3-x-330/H2O2体系具有较宽的pH使用范围(pH=2~10)。当pH=4时,罗丹明B的降解速率常数为0.834 h-1,而且催化剂具有磁性,易回收重复使用。催化机理研究表明氧空位缺陷α-Fe2O3-x催化剂的氧空位和Fe2+两种活性位点均可促进H2O2分解,而且氧空位的引入有利于污染物在催化剂表面的吸附进一步提高催化性能。
关键词: 三氧化二铁  多相芬顿催化  羟基自由基  双活性位点  表面电子调控
基金项目: 国家自然科学基金(No.21273050,21573048,21873022,51574092)资助项目。
Abstract: Intrinsically poor reactivity restricts hematite (α-Fe2O3) from heterogeneous Fenton systems. Usually, metal ion doping, noble metal loading, and compounding with other compounds to enhance their catalytic activity are necessary, making them complex, expensive, and difficult to control. Here a surface-electronic-state-modulation-based concept applied to hematite is presented. This concept enables hematite with dual reaction sites as highly reactive and reusable Fenton-like catalysts for efficient catalytic oxidation of recalcitrant organics, via activation of H2O2 and without any extra energy input. The rhodamine B degradation rate constants for α-Fe2O3-x-330/H2O2 systems were 0.834 h-1, when pH=4, and have a much wider pH working window (pH=2~10) than traditional Fenton systems. Meanwhile, the used catalyst can be easily recovered by magnetic separation. Oxygen vacancy and Fe(Ⅱ) on defective α-Fe2O3-x surfaces have been confirmed as the active sites for H2O2 activation, while the adjacent vacancy oxygens site adsorbs organic molecules and thus improves the Fenton-like catalytic performance. These findings may not only extend the environment applications of pure transition metal oxide but also stimulate new opportunities for the same as many other transition metal oxides by surface electronic-state modulation.
Keywords: α-Fe2O3 nanosheets  heterogeneous fenton catalysis  hydroxyl radical  dual reaction sites  surface-electronic-state-modulated
投稿时间:2019-02-18 修订日期:2019-06-22
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邱江源,肖碧源,覃方红,张美婷,万婷,刘锦萍,陈建华,黄在银.表面缺陷α-Fe2O3(001)纳米片双活性位点类芬顿催化剂用于降解污染物[J].无机化学学报,2019,35(9):1665-1677.
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