School of Chemical and Environmental Sciences, Henan Key Laboratory for Environmental Pollution Control, Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007, PR China.
Chemosphere. 2012 Jun;87(10):1155-60. doi: 10.1016/j.chemosphere.2012.02.023. Epub 2012 Mar 3.
In this work, Bi(4)Nb(x)Ta((1-x))O(8)I photocatalysts have been synthesized by solid state reaction method and characterized by powder X-ray diffraction, scanning electron microscope and UV-Vis near infrared diffuse reflectance spectroscopy. The photocatalytic activity of these photocatalysts was evaluated by the degradation of methyl orange (MO) in aqueous solutions under visible light, UV light and solar irradiation. The effects of catalyst dosage, initial pH and MO concentration on the removal efficiency were studied, and the photocatalytic reaction kinetics of MO degradation as well. The results indicated that Bi(4)Nb(x)Ta((1-x))O(8)I exhibited high photocatalytic activity for the removal of MO in aqueous solutions. For example, the removal efficiency of MO by Bi(4)Nb(0.1)Ta(0.9)O(8)I was as high as 92% within 12 h visible light irradiation under the optimal conditions: initial MO concentration of 5-10 mg L(-1), catalyst dosage of 6 g L(-1) and natural pH (6-8), the MO molecules could be completely degradated by Bi(4)Nb(0.1)Ta(0.9)O(8)I within 40 min under UV light irradiation, and the photodegradation efficiency reaches to 60% after 7 h solar irradiation. Furthermore, the photocatalytic degradation of Bisphenol A (BPA) was also investigated under visible light irradiation. It is found that 99% BPA could be mineralized by Bi(4)Nb(0.1)Ta(0.9)O(8)I after 16 h visible light irradiation. Through HPLC/MS, BOD, TOC, UV-Vis measurements, we determined possible degradation products of MO and BPA. The results indicated that MO was degradated into products which are easier to be biodegradable and innocuous treated, and BPA could be mineralized completely. Furthermore, the possibility for the photosensitization effect in the degradation process of MO under visible light irradiation has been excluded.
在这项工作中，通过固相反应法合成了 Bi(4)Nb(x)Ta((1-x))O(8)I 光催化剂，并通过粉末 X 射线衍射、扫描电子显微镜和紫外-可见近红外漫反射光谱对其进行了表征。通过在可见光、紫外光和太阳光照射下，评价了这些光催化剂在水溶液中对甲基橙（MO）的降解的光催化活性。研究了催化剂用量、初始 pH 和 MO 浓度对去除效率的影响，并研究了 MO 降解的光催化反应动力学。结果表明，Bi(4)Nb(x)Ta((1-x))O(8)I 对水溶液中 MO 的去除具有很高的光催化活性。例如，在最佳条件下（初始 MO 浓度为 5-10mg/L、催化剂用量为 6g/L、自然 pH 值为 6-8），Bi(4)Nb(0.1)Ta(0.9)O(8)I 在可见光照射下 12h 内对 MO 的去除效率高达 92%，在紫外光照射下，Bi(4)Nb(0.1)Ta(0.9)O(8)I 可在 40min 内完全降解 MO 分子，在太阳光照射 7h 后，光降解效率达到 60%。此外，还在可见光照射下研究了双酚 A（BPA）的光催化降解。结果发现，在可见光照射 16h 后，99%BPA 可被 Bi(4)Nb(0.1)Ta(0.9)O(8)I 矿化。通过 HPLC/MS、BOD、TOC、UV-Vis 测量，确定了 MO 和 BPA 的可能降解产物。结果表明，MO 被降解成更容易生物降解和无害化处理的产物，BPA 可被完全矿化。此外，排除了 MO 在可见光照射下降解过程中存在光敏化效应的可能性。
