2. Sensitized degradation of chlorophenols on iron oxides induced by visible light: Comparison with titanium oxide
2. Sensitized degradation of chlorophenols on iron oxides induced by visible light: Comparison with titanium oxide
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DOI：
10.1016/s0926-3373(01)00225-9
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发表时间：
2001-11
影响因子：
22.1
通讯作者：
J. Bandara;J. Mielczarski;A. López;J. Kiwi
中科院分区：
文献类型：
--
作者：
J. Bandara;J. Mielczarski;A. López;J. Kiwi
详细报道了α- fe2o3和α-FeOOH的氧化铁水悬浮液对一、二、三氯酚的光催化敏化降解。当α- fe2o3作为光催化剂时，这些化合物的降解遵循准一级动力学。α-FeOOH除对2,4-二氯苯酚（2,4- dcp）有一定的降解作用外，对氯酚无活性。在光降解过程中，氯酚与氧化铁形成表面配合物和特定氯酚在水溶液中的溶解度是控制参数。并将α- fe2o3催化剂与TiO2催化剂进行了比较。氯酚在tio2上全部矿化，而在α- fe2o3上部分矿化。在任何一种情况下，在光降解过程中产生的中间体被发现比初始化合物更容易生物降解。对单氯、二氯和三氯酚，光催化降解总量的增加顺序为：2,4,6-三氯酚(2,4,6- tcp)<2,3-二氯酚(2,3- DCP)<2-氯酚(2- CP)< 2,4 -DCP。前一个序列表明，顽固的2,4-二氯苯酚比本研究中测试的其他氯酚降解得更快。在α- fe2o3和tio2上，氯酚的光降解机制是通过初始化合物的对羟基化进行的，这是高压液相色谱法在降解过程中发现的中间体。
The sensitized photocatalytic degradation of mono-, di- and trichlorophenols on iron oxides aqueous suspensions of α-Fe2O3and α-FeOOH is reported in detail. The degradation of these compounds followed pseudo-first-order kinetics when α-Fe2O3was used as photocatalyst. α-FeOOH was found to be inactive for chlorophenols degradation with the exception of 2,4-dichlorophenol (2,4-DCP) where a modest effect was observed. The formation of a surface complex by the chlorophenols with the iron oxide and the solubility of the particular chlorophenol in aqueous solution were observed to be the controlling parameters during the photodegradation. The results obtained with the most active catalyst α-Fe2O3are compared with TiO2. Total mineralization of chlorophenols was observed on TiO2while on α-Fe2O3only partial mineralization was observed. In either case, the intermediates produced in solution during the photodegradation were found to be significantly more biodegradable than the initial compound. For mono-, di- and trichlorophenols the overall photocatalytic degradation was observed to increase in the order: 2,4,6-trichlorophenol (2,4,6-TCP)<2,3-dichlorophenol (2,3- DCP )<2- chlorophenol (2- CP) <2 ,4-DCP. The former sequence shows that the recalcitrant 2,4-DCP degrades more rapidly than other chlorophenols tested during this study. The photodegradation of chlorophenols on α-Fe2O3and TiO2proceeds mechanistically through para-hydroxylation of the initial compound as suggested by the intermediates found by high-pressure liquid chromatography HPLC during the course of the degradation.