Discoloration and mineralization of orange II using different heterogeneous catalysts containing Fe: A comparative study
Discoloration and mineralization of orange II using different heterogeneous catalysts containing Fe: A comparative study
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DOI：
10.1021/es049811j
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发表时间：
2004-11-01
影响因子：
11.4
通讯作者：
Yue, PL
中科院分区：
文献类型：
--
作者：
Feng, JY;Hu, XJ;Yue, PL
四种含铁的非均相催化剂，包括蒙脱石-粘土基铁纳米复合物（Fe-B）、赤铁矿（α-Fe 2 O3）、无定形FeOOH和煅烧FeOOH（表示为FeOOOH-M），用于在10 mM H2 O2和8 W UVC存在下在两种不同的初始溶液pH值（3.0和6.13）下0.2 mM橙子II的光芬顿变色和矿化。结果表明，在初始pH = 3.0时，它们的光催化活性顺序为Fe-B > FeOOH，FeOOOH-M> α-N_2O_3。当Fe-B纳米复合材料、FeOOH和FeOOOH-M用作非均相催化剂时，非均相和均相光芬顿反应都是0.2 mM橙子II变色和矿化的原因，因为均相光芬顿反应由于存在从催化剂中浸出的Fe离子而发生。在初始pH为6.6的溶液中，它们的光催化活性仍然遵循Fe-B > FeOOH，FeOOOH-M远大于α-Fe_2 O_3的顺序。然而，只有非均相光芬顿反应占0.2 mM橙子II的变色和矿化，因为从催化剂的Fe浸出显着抑制。在α-Fe 2 O 3作为催化剂的情况下，无论在初始溶液pH为3.0或6.6时，对于0.2 mM橙子II的变色和矿化，仅发生非均相光芬顿反应，因为从催化剂中浸出的Fe可以忽略不计。研究了在两种不同初始pH值下，四种催化剂对橙子II的表观脱色动力学。
Four heterogeneous catalysts containing Fe including a bentonite-clay-based Fe nanocomposite (Fe-B), hematite (alpha-Fe2O3), amorphous FeOOH, and calcined FeOOH (denoted as FeOOH-M) were employed for the photo-Fenton discoloration and mineralization of 0.2 mM Orange II in the presence of 10 mM H2O2 and 8 W UVC at two different initial solution pH values (3.0 and 6.13). It was found that, at an initial solution pH of 3.0, their photocatalytic activities follow the order Fe-B > FeOOH, FeOOH-M > alpha-N2O3. When the Fe-B nanocomposite, FeOOH, and FeOOH-M were used as heterogeneous catalysts, both heterogeneous and homogeneous photo-Fenton reactions were responsible for the discoloration and mineralization of 0.2 mM Orange II because homogeneous photo-Fenton reaction occurred due to the presence of Fe ions leached from the catalysts. At an initial solution pH of 6.6, their photocatalytic activities still follow the order Fe-B > FeOOH, FeOOH-M much greater than alpha-Fe2O3. However, only heterogeneous photo-Fenton reaction accounted for the discoloration and mineralization of 0.2 mM Orange II because Fe leaching from the catalysts was significantly depressed. In the case of alpha-Fe2O3 as a catalyst, whether at an initial solution pH of 3.0 or 6.6, only heterogeneous photo-Fenton reaction happened for the discoloration and mineralization of 0.2 mM Orange II because Fe leaching from the catalyst is negligible. The apparent discoloration kinetics of Orange II with the four catalysts at two different initial solution pH values was also investigated.