The evaluation of the photocatalytic activity of magnetic and non-magnetic polymorphs of Fe2O3 in natural sunlight exposure: A comparison of photocatalytic activity
The evaluation of the photocatalytic activity of magnetic and non-magnetic polymorphs of Fe2O3 in natural sunlight exposure: A comparison of photocatalytic activity
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DOI：
10.1016/j.apsusc.2018.04.219
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发表时间：
2018-09-01
影响因子：
6.7
通讯作者：
Hameed, A.
中科院分区：
文献类型：
--
作者：
Aslam, M.;Qamar, M. Tariq;Hameed, A.
通过简单的表面活性剂辅助水凝胶路线合成了氧化铁 (Fe2O3) 的非磁性和磁性多晶型物，分别为：α-Fe2O3（赤铁矿）和 γ-Fe2O3（磁赤铁矿）。通过漫反射、光致发光和拉曼光谱对合成的多晶型物的光学性质进行表征，同时通过FESEM、HRTEM、XRD和XPS进行形态、结构、化学和电子态评估。通过电化学方法检查了材料的电荷传输和稳定性。评估了合成多晶型物在可见光区域和全光谱自然阳光下降解 2-氯苯酚和 2-硝基苯酚的光催化活性。两种多晶型物在全光谱太阳光照射下均表现出显着高的酚类底物降解活性，然而，在太阳光可见光区域的活性相对较低。当在光催化实验之前将多晶型物暴露于全光谱太阳光时，注意到可见光区域的活性显着增加。暴露和未暴露样品的比较揭示了缺陷的诱导，这些缺陷充当激发电子的陷阱并增加多晶型物的活性。 (C) 2018 Elsevier B.V. 保留所有权利。
The non-magnetic and magnetic polymorphs of iron oxide (Fe2O3) namely: alpha-Fe2O3 (hematite) and gamma-Fe2O3 (maghemite) respectively, were synthesized by a facile surfactant aided hydrogel route. The synthesized polymorphs were characterized by diffuse reflectance, photoluminescence and raman spectroscopy for optical properties whereas the morphological, structural, chemical and electronic state evaluation were performed by FESEM, HRTEM, XRD, and XPS. The charge transport and the stability of the materials were examined electrochemically. The photocatalytic activity of the synthesized polymorphs was evaluated for the degradation of 2-chlorophenol and 2-nitrophenol in the exposure of the visible region and complete spectrum natural sunlight. Both the polymorphs exhibited a significantly high activity for the degradation of the phenolic substrate in the exposure of the complete spectrum of sunlight, however, the activity in the visible region of the sunlight was relatively lower. A substantial increase in the activity in the visible region was noticed when the polymorphs were exposed to complete spectrum sunlight prior to the photocatalytic experiments. The comparison of the exposed and unexposed samples revealed the induction of defects that served as traps for the excited electrons and increased activity of the polymorphs. (C) 2018 Elsevier B.V. All rights reserved.