Photocatalytic activity of La-doped ZnO for the degradation of monocrotophos in aqueous suspension
Photocatalytic activity of La-doped ZnO for the degradation of monocrotophos in aqueous suspension
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DOI：
10.1016/j.molcata.2006.11.008
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发表时间：
2007-04-02
影响因子：
--
通讯作者：
Ariga, K.
中科院分区：
文献类型：
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作者：
Anandan, S.;Vinu, A.;Ariga, K.
合成了不同La含量的La掺杂的氧化锌纳米颗粒，并用X射线衍射仪、紫外-可见光谱、原子力显微镜、X射线光电子能谱、高分辨扫描电子显微镜等手段对其进行了表征。X射线衍射结果表明，La3+以细小的La2O3团簇形式均匀分散在纳米氧化锌表面。结果表明，La掺杂的氧化锌的颗粒尺寸比纯的氧化锌要小得多，并且随着掺杂量的增加而减小。原子力显微镜观察到La掺杂的氧化锌表面粗糙、孔洞大，这是提高其光催化活性的关键。研究了La掺杂氧化锌对久效磷(MCP)的光催化降解活性。研究了不同La负载量的La掺杂氧化锌的光催化活性，考察了MCP的吸附、波长光、溶液pH对光催化活性的影响，并与纯的氧化锌和纯的二氧化钛进行了比较。结果表明，当La掺杂量达到0.8wt%时，随着La含量的增加，MCP在氧化锌上的降解速率先增大后减小。研究发现，La掺杂有助于在较短的辐照时间内实现MCP的完全矿化。在所研究的催化剂中，掺杂0.8wt%La的氧化锌活性最高，表现出较高的相对光子效率和光催化降解MCP的活性。(C)2006爱思唯尔B.V.保留所有权利。
La-doped ZnO nanoparticles with different La contents were synthesized and characterized by various sophisticated techniques such as XRD, UV-vis, AFM, XPS, and HR-SEM. The XRD results revealed that La3+ is uniformly dispersed on ZnO nanoparticles in the form of small La2O3 cluster. It was found that the particle size of La-doped ZnO is much smaller as compared to that of pure ZnO and decreases with increasing La loading. Rough and high porous surface of La-doped ZnO was observed by AFM, which is critical for enhancing the photocatalytic activity. The photocatalytic activity of La-doped ZnO in the degradation of monocrotophos (MCP) was studied. The effects of the adsorption of MCP, lights of wavelength, and the solution pH on the photocatalytic activity of La-doped ZnO with different La loading were studied and the results were compared with pure ZnO and pure TiO2. It was observed that the rate of degradation of MCP over La-doped ZnO increases with increasing La loading up to 0.8 wt% and then decreases. It was found that the doping of La in ZnO helps to achieve complete mineralization of MCP within a short irradiation time. Among the catalyst studied, the 0.8 wt% La-doped ZnO was the most active, showing high relative photonic efficiencies and high photocatalytic activity for the degradation of MCP. (c) 2006 Elsevier B.V. All rights reserved.