Synthesis, photoelectric properties and photocatalytic activity of the Fe2O3/TiO2 heterogeneous photocatalysts
Synthesis, photoelectric properties and photocatalytic activity of the Fe2O3/TiO2 heterogeneous photocatalysts
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Fe2O3/TiO2异质光催化剂的合成、光电性能及光催化活性
DOI：
10.1039/c002460k
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发表时间：
2010-01-01
影响因子：
3.3
通讯作者：
Wang, Dejun
中科院分区：
文献类型：
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作者：
Peng, Linlin;Xie, Tengfeng;Wang, Dejun
通过在TiO 2微米棒表面浸渍Fe 3+并在300 ℃下焙烧，制备了不同Fe 2 O3/TiO 2质量比的Fe 2 O3/TiO 2多相光催化剂。利用扫描电子显微镜（SEM）、高分辨透射电子显微镜（HRTEM）、光致发光光谱（PL）和X射线衍射（XRD）对样品进行了表征。以橙子II为目标染料，在可见光（λ> 420 nm）下，考察了Fe 2 O3/TiO 2复合材料、纯Fe 2 O3和纯TiO 2的光催化活性。实验表明，在可见光照射下，Fe 2 O3/TiO 2复合光催化剂对水溶液中的橙子II的光降解效果优于纯Fe 2 O3或TiO 2。当Fe 2 O3/TiO 2的质量比为7：3时，橙子II的光降解率最高。我们还利用表面光电压（SPV）和瞬态光电压（TPV）技术比较了Fe_2O_3/TiO_2多相光催化剂和纯Fe_2O_3的光电性能。基于光电压响应，我们讨论了Fe_2O_3和TiO_2之间的异质界面对光生载流子传输特性的影响。结果表明，Fe_2O_3/TiO_2复合材料中Fe_2O_3和TiO_2之间异质结的形成是提高Fe_2O_3/TiO_2复合材料光催化活性的关键。
Fe2O3/TiO2 heterogeneous photocatalysts with different mass ratios of Fe2O3 vs. TiO2 were synthesized by impregnation of Fe3+ on the surface of TiO2 microrods and calcination at 300 degrees C. Scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), photoluminescence spectra and X-ray diffraction (XRD) have been used to characterize the samples. The photocatalytic activities of Fe2O3/TiO2 heterocomposites, pure Fe2O3 and pure TiO2 were evaluated by the photodegrading efficiency of Orange II under visible light (lambda > 420 nm). The experiments demonstrated that Orange II in aqueous solution was more efficiently photodegraded using Fe2O3/TiO2 heterogeneous photocatalysts than either pure Fe2O3 or TiO2 under visible light irradiation. With an optimal mass ratio of 7 : 3 in Fe2O3/TiO2 the highest rate of Orange II photodegradation was achieved under the experimental conditions. We have also compared the photoelectric properties of Fe2O3/TiO2 heterogeneous photocatalysts with that of pure Fe2O3 by surface photovoltage (SPV) and transient photovoltage (TPV) techniques. Based on the photovoltage responses, we discussed the influence of the hetero-interface between Fe2O3 and TiO2 on transfer characteristics of photogenerated charge carriers. We demonstrated that the formation of heterojunctions between Fe2O3 and TiO2 for Fe2O3/TiO2 composites was pivotal for improving the separation and thus restraining the recombination of photogenerated electrons and holes, which accounts for the enhancement of photocatalytic activity.