Chen Yongzhou, Li Nian, Zhang Ye, Zhang Lide
Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, PR China.
Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, PR China.
J Colloid Interface Sci. 2014 May 15;422:9-15. doi: 10.1016/j.jcis.2014.01.013. Epub 2014 Jan 25.
Novel low-cost layered Fe-titanate catalyst for photo-Fenton degradation of organic contaminants was successfully developed by ion exchange of Fe(3+) with Na(+) layered nano Na-titanates which was prepared by alkali hydrothermal method. The as prepared materials were characterized by powder X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray spectrometer (EDX). The catalytic activity of the Fe-titanate catalyst was evaluated by the decolorization of three different dyes (rhodamine 6G (R6G), methyl blue (MB), and methyl orange (MO)) under UV irradiation at room temperature. Effect of several important factors such as Fe loading in the catalyst, initial solution pH, catalyst dosage, H2O2 amount, and reaction time was systematically studied. It was found that the decolorization was very efficient for all three dyes. The efficiency reached 98% for R6G, 98.5% for MB, and 97% for MO, respectively, under optimal conditions. The oxidation process was quick, and only 15 min is needed for all three dyes. Moreover, the Fe-titanate catalyst could be used in a wider and near neutral pH range compared with classic Fenton systems which need to be operated at around pH 3.0. Kinetic analysis results showed that the oxidation kinetics was accurately represented by pseudo-first-order model. More importantly, the catalyst was very stable and could be reused for at least four cycles when operated under near neutral pH. The Fe leaching from the catalyst measured was almost negligible, which not only demonstrated the stability of the catalyst, but also avoided the formation of secondary Fe pollution. Therefore, the reported Fe-titanates are promising nanomaterials which can be used as Fenton like catalyst for the degradation of organic contaminant in wastewater.
通过用Fe(3+)与采用碱水热法制备的层状纳米Na-钛酸盐中的Na(+)进行离子交换，成功开发出了用于光芬顿降解有机污染物的新型低成本层状铁钛酸盐催化剂。通过粉末X射线衍射分析（XRD）、场发射扫描电子显微镜（FESEM）和能量色散X射线光谱仪（EDX）对所制备的材料进行了表征。在室温下紫外光照射下，通过三种不同染料（罗丹明6G（R6G）、亚甲基蓝（MB）和甲基橙（MO））的脱色来评估铁钛酸盐催化剂的催化活性。系统研究了几个重要因素的影响，如催化剂中的铁负载量、初始溶液pH值、催化剂用量、H2O2量和反应时间。发现对所有三种染料的脱色都非常有效。在最佳条件下，R6G的脱色效率达到98%，MB为98.5%，MO为97%。氧化过程很快，三种染料都只需15分钟。此外，与需要在pH约3.0下运行的经典芬顿体系相比，铁钛酸盐催化剂可在更宽的近中性pH范围内使用。动力学分析结果表明，氧化动力学可以用准一级模型准确表示。更重要的是，该催化剂非常稳定，在近中性pH下运行时可重复使用至少四个循环。测得的催化剂中铁的浸出几乎可以忽略不计，这不仅证明了催化剂的稳定性，还避免了二次铁污染的形成。因此，所报道的铁钛酸盐是有前途 的纳米材料，可作为类芬顿催化剂用于降解废水中的有机污染物。
