Photocatalytic reduction of Pb(II) over TiO2: New insights on the effect of different electron donors
Photocatalytic reduction of Pb(II) over TiO2: New insights on the effect of different electron donors
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DOI：
10.1016/j.apcatb.2008.05.012
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发表时间：
2008-12
影响因子：
22.1
通讯作者：
L. Murruni;F. Conde;G. Leyva;M. Litter
中科院分区：
文献类型：
--
作者：
L. Murruni;F. Conde;G. Leyva;M. Litter
在甲醇、乙醇、2-丙醇、柠檬酸 (Cit) 和甲酸 (FA) 等电子给体存在下，进行了 TiO2 (Degussa P-25) 氮气下光催化去除 Pb(II) 的实验，以研究它们对去除效率的影响。甲酸和 2-丙醇显示出最高的效果，但第一种被认为是更好的添加剂，因为它可以以低五倍的浓度使用，并且不会在系统中引入有毒的降解产物。在低浓度甲酸添加的情况下，当电子供体完全消耗时观察到Pb的再溶解。产物的形成取决于反应条件和电子供体的性质，但在所有情况下，主要鉴定的产物都是胶体颗粒形式的零价 Pb，如 XRD 和 XPS 分析所示。提出了涉及减少自由基的机制来解释 Pb(II) 的去除和供体的比较效率。
Experiments of Pb(II) photocatalytic removal under nitrogen over TiO2(Degussa P-25) were performed in the presence of electron donors such as methanol, ethanol, 2-propanol, citric acid (Cit) and formic acid (FA) in order to study their effects on the removal efficiencies. Formic acid and 2-propanol showed the highest effect, but the first one was considered a better additive because it can be used at a concentration five-fold lower and it does not introduce toxic degradation products in the system. In the case of formic acid addition at low concentration, redissolution of Pb was observed when the electron donor was completely consumed. Product formation was dependent on the reaction conditions and on the nature of electron donor, but the main identified product in all cases was zerovalent Pb, in the form of colloidal particles, as demonstrated by XRD and XPS analysis. Mechanisms involving reducing radicals were proposed to explain Pb(II) removal and the comparative efficiency of the donors.