Highly active Fe2O3-doped TiO2 photocatalyst for degradation of trichloroethylene in air under UV and visible light irradiation: Experimental and computational studies
Highly active Fe2O3-doped TiO2 photocatalyst for degradation of trichloroethylene in air under UV and visible light irradiation: Experimental and computational studies
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DOI：
10.1016/j.apcatb.2014.10.023
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发表时间：
2015-04-01
影响因子：
22.1
通讯作者：
Menbari, Sadra
中科院分区：
文献类型：
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作者：
Banisharif, Alireza;Khodadadi, Abbas Ali;Menbari, Sadra
采用超声波辅助共沉淀法合成了 0.0-5.0 wt% Fe2O3 掺杂的 TiO2 光催化剂，并用于降解空气中 500 ppm 三氯乙烯 (TCE)。光催化剂在 100-400 摄氏度下进行处理，并通过高分辨率透射电子显微镜 (HRTEM)、粉末 X 射线衍射 (XRD)、BET 表面积以及拉曼、紫外-可见和光致发光 (PL) 光谱进行表征。对于在 100 摄氏度下处理的样品，XRD 图谱显示没有明显的峰，而 HRTEM 显微照片显示了晶体结构和衍射图样，拉曼光谱显示了锐钛矿型 TiO2 的宽而弱的峰。当 TiO2 中添加 0.1 wt% Fe2O3 时，表面积增加了 1.87 倍，达到 448 m(2)/g。 UV-vis 分析表明，随着样品中 Fe2O3 含量的增加，带隙能量从纯 TiO2 的 3.22 eV 降低到 5.0 wt% Fe2O3 掺杂 TiO2 的 2.60 eV。密度泛函理论模拟表明，当Fe3+掺杂到锐钛矿型TiO2上或FeO、Fe2O3或Fe4O6吸附在锐钛矿型TiO2上时，不良间隙减小，氧化铁-TiO2在可见光区域表现出光催化活性。合成的 TiO2 去除 TCE 的光催化活性比 Degussa P25 高出约两倍。此外，在 100 摄氏度下干燥的 0.1 wt% Fe2O3 掺杂的 TiO2 样品显示出约 97% 的最大光催化 TCE 转化率，并含有少量的 CO 作为危险副产品。随着样品处理温度的升高，光催化活性下降。在可见光照射下，Fe2O3 掺杂的 TiO2 样品也观察到 TCE 的显着光催化降解。 (C) 2014 Elsevier B.V. 保留所有权利。
0.0-5.0 wt% Fe2O3-doped TiO2 photocatalysts were synthesized by an ultrasonic-assisted co-precipitation method and used for degradation of 500 ppm trichloroethylene (TCE) in air. The photocatalysts were treated at 100-400 degrees C and characterized by high resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), BET surface area, and Raman, UV-vis, and photoluminescence (PL) spectroscopies. For the samples treated at 100 degrees C, XRD patterns show no significant peaks, while HRTEM micrographs indicate crystalline structures and diffraction patterns and Raman spectra reveal wide and weak peaks of anatase TiO2. As 0.1 wt% Fe2O3 is added to TiO2, the surface area increases by a factor of 1.87 and reach to 448 m(2)/g. UV-vis analyses indicate that, as the Fe2O3 content of the samples increases, the band gap energies decrease from 3.22 eV for the pure TiO2 to 2.60 eV for 5.0 wt% Fe2O3-doped TiO2. Density functional theory simulations show that, when Fe3+ is doped into or FeO, Fe2O3 or Fe4O6 is adsorbed on anatase TiO2, the bad gap reduces and the iron oxide-TiO2 show photo catalytic activity in visible light region. The synthesized TiO2 showed about two times higher photocatalytic activity for TCE removal than that of Degussa P25. Moreover, 0.1 wt% Fe2O3-doped TiO2 sample dried at 100 degrees C showed a maximum photocatalytic TCE conversion of about 97% with minor amounts of CO as a hazardous byproduct. As the treatment temperature of the samples increase, the photocatalytic activity declines. Significant photocatalytic degradation of TCE was also observed for the Fe2O3-doped TiO2 samples, under visible light irradiation. (C) 2014 Elsevier B.V. All rights reserved.