Photocatalytic degradation of trichloroethylene in aqueous phase using nano-ZNO/Laponite composites.
Photocatalytic degradation of trichloroethylene in aqueous phase using nano-ZNO/Laponite composites.
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DOI：
10.1016/j.jhazmat.2013.10.017
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发表时间：
2013-12
影响因子：
13.6
通讯作者：
J. Joo;C. Ahn;D. Jang;Y. Yoon;J. K. Kim;L. Campos;Hosang Ahn
中科院分区：
文献类型：
--
作者：
J. Joo;C. Ahn;D. Jang;Y. Yoon;J. K. Kim;L. Campos;Hosang Ahn
在不增加光催化剂回收难度的情况下，评价了纳米氧化锌/磷灰石复合材料(NZLc)作为二氧化钛的有效替代物矿化三氯乙烯的可行性。根据实验观察，NZLc在紫外光照射下对TCE的去除是一个多反应过程(即吸附、光解和光催化)。TCE的吸附在热力学上是有利的，这是由于疏水分配到交联化的聚乙烯醇中，以及氧化锌和膨润土在高比表面积矿物表面的吸附。在紫外光照射下，NZLc可以显著提高TCE的降解效率，表明发生了氧化锌介导的多相光催化降解。然而，降解效率随着实验条件(如TCE的初始浓度、NZLc的负载量、光照强度和初始溶液的pH)而变化。虽然NZLc对TCE的去除是吸附、光解和光催化的综合作用，但TCE在氧化锌表面的光催化降解是关键。因此，所开发的NZLc可以作为悬浮二氧化钛粉末的有效替代品，并克服了在不同水源下降解TCE的缺点(例如，光催化剂的过滤和回收)。
The feasibility of nano-ZnO/Laponite composites (NZLc) as a valid alternative to TiO2to mineralize trichloroethylene (TCE) without difficulties for recovery of photocatalysts was evaluated. Based on the experimental observations, the removal of TCE using NZLc under UV irradiation was multiple reaction processes (i.e., sorption, photolysis, and photocatalysis). Sorption of TCE was thermodynamically favorable due to the hydrophobic partitioning into crosslinked poly vinyl alcohol, and the adsorption onto high-surface-area mineral surfaces of both ZnO and Laponite. The degradation efficiency of TCE can be significantly improved using NZLc under UV irradiation, indicating that ZnO-mediated heterogeneous photocatalytic degradation occurred. However, the degradation efficiency was found to vary with experimental conditions (e.g., initial concentration of TCE, loading amount of NZLc, the intensity of light and initial solution pH). Although the removal of TCE by NZLc was found to be a complex function of sorption, photolysis, and photocatalysis, the photocatalytic degradation of TCE on the surface of ZnO was critical. Consequently, developed NZLc can be applied as a valid alternative to suspended TiO2powder, and overcome drawbacks (e.g., filtration and recovery of photocatalysts) in degradation of TCE for various water resources.