Hydrothermal synthesis and characterization of novel PbWO4 microspheres with hierarchical nanostructures and enhanced photocatalytic performance in dye degradation
Hydrothermal synthesis and characterization of novel PbWO4 microspheres with hierarchical nanostructures and enhanced photocatalytic performance in dye degradation
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具有分级纳米结构和增强染料降解光催化性能的新型 PbWO4 微球的水热合成和表征
DOI：
10.1016/j.cej.2012.12.064
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发表时间：
2013-03-01
影响因子：
15.1
通讯作者：
Chen, Jianchai
中科院分区：
文献类型：
--
作者：
Yu, Changlin;Cao, Fangfang;Chen, Jianchai
在水热条件下，通过调节pH值，制备了不同形貌的钨酸铅晶体，包括14面多面体、分级微球和纳米颗粒。采用氮气物理吸附、粉末X射线衍射、扫描电子显微镜、透射电子显微镜、紫外-可见漫反射光谱、光致发光发射光谱和傅里叶变换红外光谱等对样品进行了表征。研究了不同纳米结构的PbWO 4晶体在紫外光（365 nm）下对酸性橙子II染料的光催化降解性能。提出了不同形貌PbWO 4晶体的生长机制。光催化性能测试表明，PbWO 4晶体的性能强烈依赖于其形貌。在pH 7.0、140 ℃条件下制备的PbWO 4纳米微球在循环反应中表现出最高的活性和稳定性。染料在PbWO 4晶体上的降解动力学符合准一级动力学模型。增强的光催化性能归因于具有高表面积和改善的表面性质的独特的分级纳米结构。此外，高结晶度的PbWO 4微球表现出增强的催化活性，由于较低的复合率的光生电子/空穴对。这些新的分级PbWO 4微球在环境净化应用中有希望。(C)2013爱思唯尔有限公司版权所有。
Novel PbWO4 crystals with different morphologies, 14-faceted polyhedrons, hierarchical microspheres and nanoparticles, were fabricated by adjusting pH value under hydrothermal conditions. The as-prepared PbWO4 samples were characterized by nitrogen-physical adsorption, powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectra, photoluminescence emission spectroscopy, and Fourier transform infrared spectroscopy. The photocatalytic performance of the PbWO4 crystals with different nanostructures in degradation of the acid orange II dye under UV light (365 nm) was investigated. The plausible growth mechanisms for PbWO4 crystals with different morphologies were proposed. Photocatalytic tests showed that the performance of PbWO4 crystals strongly depended on their morphologies. PbWO4 microspheres with hierarchical nanostructures prepared under pH 7.0 at 140 degrees C exhibited the highest activity and stability in recycling reaction. The degradation kinetics of dye over PbWO4 crystals was found to conform to the pseudo-first order model. The enhanced photocatalytic performance was attributed to the unique hierarchical nanostructures with high surface area and improved surface properties. Moreover, the high crystallinity of PbWO4 microspheres exhibited an enhanced catalytic activity owing to lower recombination rate of photo-generated electron/hole pairs. These novel hierarchical PbWO4 microspheres hold promise in applications of environmental purification. (C) 2013 Elsevier B.V. All rights reserved.