Palygorskite- and Halloysite-TiO2 nanocomposites: Synthesis and photocatalytic activity
Palygorskite- and Halloysite-TiO2 nanocomposites: Synthesis and photocatalytic activity
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DOI：
10.1016/j.clay.2010.07.013
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发表时间：
2010-09-01
影响因子：
5.6
通讯作者：
Katsuki, H.
中科院分区：
文献类型：
--
作者：
Papoulis, D.;Komarneni, S.;Katsuki, H.
以异丙酸钛为前驱体，在180℃的水热条件下，采用溶胶-凝胶法将锐钛矿形式的TiO2沉积在粘土表面，制备了Palygorskite-TiO2纳米复合材料。采用x射线衍射（XRD）、扫描电子显微镜（SEM）、能谱分析（EDS）、透射电子显微镜（TEM）、傅里叶变换红外光谱（ATR-FTIR）衰减全反射、BET分析N-2表面积对样品的物相组成、颗粒形貌和物理性质进行了表征。测定了粘土-二氧化钛纳米复合材料分解NOx气体的光催化活性。经TiO2处理后，高岭土和坡高岭土样品的介孔大小分别为5.6 nm和6.5 nm左右，而高岭土的大孔（即高岭土管的中心孔）消失。后者是由于二氧化钛纳米粒子覆盖了高岭土管的中心孔，因此二氧化钛处理的高岭土的孔径明显变小。在可见光照射（λ > 510 nm）和紫外光照射（λ > 290 nm）下，粘土-二氧化钛样品的NOx气体分解活性显著高于标准商用二氧化钛P25。(C) 2010 Elsevier B.V.版权所有
Palygorskite-TiO2 nanocomposites were prepared by deposition of the anatase form of TiO2 on the clay surfaces using a sol-gel method with titanium isopropoxide as a precursor under hydrothermal treatment at 180 degrees C. The same procedure was followed in the formation of halloysite-TiO2 nanocomposites using a halloysite sample. Phase composition, particle morphology and physical properties of these samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and microanalysis by energy dispersive spectrometry (EDS), transmission electron microscopy (TEM), attenuated total reflection using Fourier transform infrared spectroscopy (ATR-FTIR) and N-2 surface area analysis by BET. The photocatalytic activities of clay-titania nanocomposites in decomposing NOx gas were measured. After treating with TiO2, the halloysite and palygorskite samples showed mesopores of about 5.6 and 6.5 nm, respectively, while the macropores of halloysite (central hole in halloysite tubes) disappeared. The latter is attributed to the covering of the central hole in halloysite tubes by TiO2 nanoparticles and for that reason the pore size of the TiO2-treated halloysite was significantly smaller. The clay-titania samples showed significantly higher activity in decomposing NOx gas under visible-light irradiation (lambda > 510 nm) and UV light irradiation (lambda > 290 nm) compared to that of the standard commercial titania, P25. (C) 2010 Elsevier B.V. All rights reserved.