Effect of suspended TiO2 physicochemical characteristics on benzene derivatives photocatalytic degradation
Effect of suspended TiO2 physicochemical characteristics on benzene derivatives photocatalytic degradation
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DOI：
10.1016/j.apcatb.2007.08.007
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发表时间：
2008-01-17
影响因子：
22.1
通讯作者：
Pulgarin, C.
中科院分区：
文献类型：
--
作者：
Gumy, D.;Giraldo, S. A.;Pulgarin, C.
根据其物理化学性质，系统地表征了七种不同的适用于水解毒的TiO（2）样品。除一种来自Degussa P25的锐钛矿-金红石混合催化剂外，所有光催化剂均具有纯锐钛矿晶相。TiO（2）样品的粒径在5 ~ 700 nm之间，与BET比表面积（ABET）呈负相关。用电声法测量了不同pH值下胶体悬浮液的表面性质。聚集体的大小似乎取决于溶液的pH值。TiO（2）样品的等电点（IEP < 3）在酸性和中性之间，以4种苯类化合物为模型污染物，研究了TiO（2）样品对水体中有机物的解毒效果，并对TiO（2）的性质对有机物降解动力学的影响进行了研究。TiO（2）表面电荷对有机物降解动力学有显著影响。事实上，化合物的降解大大增强了酸性TiO（2）。此外，ABET对化合物的初级降解和总矿化量的影响不同。强吸附的污染物，即那些含有羧基，苯甲酸（BA）和4-羟基苯甲酸（HBA）的主要降解动力学，是由大ABET增强，而苯酚和4-硝基苯酚（NP）的降解没有。另一方面，小的ABET是不利的，并且对于有效的总有机碳（TOC）去除存在最佳值。此外，混合晶体结构，Degussa P25，表现出更高的光活性比纯TiO 2（2），一般接受和报告在以前的研究。(C)2007 Elsevier B. V.保留所有权利。
Seven different TiO(2) samples suitable for water detoxification were systematically characterized according to their physicochemical properties. Except for one mixed catalyst anatase-rutile from Degussa P25, all photocatalysts had a pure anatase crystalline phase. The particle size of the TiO(2) samples varied from about 5 to 700 nm and was inversely correlated with the BET specific surface area (ABET). Surface properties of colloidal suspensions measured by electroacoustic methods were evaluated at different pH values. The aggregate size appeared to be dependent on the pH value of the solution. The isoelectric point (IEP) of the TiO(2) samples ranged from very acidic (IEP < 3) to neutral values.Four benzene derivatives were chosen as model pollutants to assess the TiO(2) samples efficiency on water detoxification.The organic degradation kinetics were influenced in a different way by the TiO(2) characteristics. The surface charge of TiO(2) samples was found to affect significantly the organic degradation kinetics. Indeed, the compounds degradation was greatly enhanced by acidic TiO(2). Moreover, the compounds primary degradation and the total mineralization were affected differently by the ABET. The primary degradation kinetics of strongly adsorbed pollutants, i.e. those containing a carboxyl group, benzoic acid (BA) and 4-hydroxybenzoic acid (HBA), is enhanced by large ABET, whereas phenol and 4-nitrophenol (NP) degradation was not. On the other hand, a small ABET was not advantageous, and there is an optimum value for an efficient total organic carbon (TOC) removal. In addition, the mixed crystalline structure, Degussa P25, showed a higher photoactivity than pure anatase TiO(2), as generally accepted and reported in previous studies. (C) 2007 Elsevier B.V. All rights reserved.