Synergy effect in the photocatalytic degradation of phenol on a suspended mixture of titania and activated carbon
Synergy effect in the photocatalytic degradation of phenol on a suspended mixture of titania and activated carbon
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DOI：
10.1016/s0926-3373(98)00051-4
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发表时间：
1998-10-12
影响因子：
22.1
通讯作者：
Herrmann, JM
中科院分区：
文献类型：
--
作者：
Matos, J;Laine, J;Herrmann, JM
苯酚的光催化降解，选择作为一个芳香族模型分子，已在室温下（20摄氏度）与二氧化钛和活性炭（AC）的悬浮混合物接触进行。当固体混合时，观察到非加和吸附容量，这归因于强相互作用，涉及二氧化钛和钙的表面的一半。AC的14%。一级反应速率常数增加了2.5倍，观察到协同效应。对于纯二氧化钛，相同的主要中间产物（氢醌和苯醌），但在一个小得多的数量和寿命期间发现，这表明相同的反应机制发生在光惰性AC的存在下，协同效应归因于AC上的苯酚的延长吸附，然后转移到二氧化钛，在那里它是光催化降解。协同效应不能通过先前的物理处理的固体混合物，如研磨和超声处理得到改善。当在纯化水中未检测到痕量有机化合物时，一些苯酚仍然吸附在AC上。这种吸附的苯酚可以被破坏的光照二氧化钛，同时保持紫外线照射。这种组合的光催化系统可能会出现作为一个新的性能，更有效的时间更短的净化稀释使用过的沃茨。(C)1998 Elsevier Science B.V.保留所有权利。
The photocatalytic degradation of phenol, chosen as an aromatic model molecule, has been performed at room temperature (20 degrees C) in contact with a suspended mixture of titania and of activated carbon (AC). Non-additive adsorption capacities were observed when the solids were mixed, and this was ascribed to a strong interaction, involving half of the surface of titania and ca. 14% of that of AC. A synergy effect was observed with an increase of the first order rate constant by a factor of 2.5, As for neat titania, the same main intermediate products (hydroquinone and benzoquinone) were found but in much smaller quantities and during a much smaller lifetime, suggesting that the same reaction mechanism occurred in the presence of photoinactive AC, The synergy effect was ascribed to an extended adsorption of phenol on AC followed by a transfer to titania where it is photocatalytically degraded. The synergy effect could not be improved by previous physical treatments of the solid mixture such as grinding and sonication. Some phenol remained adsorbed on AC when no traces of organic compounds were detected in the purified water. This adsorbed phenol could be destroyed by illuminated titania while maintaining UV-irradiation. This combined photocatalytic system may appear as a new performing one, more efficient with a shorter time necessary for decontaminating diluted used waters. (C) 1998 Elsevier Science B.V. All rights reserved.