Nanodiamond–TiO2 composites for photocatalytic degradation of microcystin-LA in aqueous solutions under simulated solar light
Nanodiamond–TiO2 composites for photocatalytic degradation of microcystin-LA in aqueous solutions under simulated solar light
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DOI：
10.1039/c5ra08812g
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发表时间：
2015-07
期刊：
影响因子：
3.9
通讯作者：
M. Sampaio;L. M. Pastrana-Martínez;Adrián M. T. Silva;J. G. Buijnsters;Changseok Han;Cláudia G. Silva;S. Carabineiro;D. Dionysiou;J. Faria
中科院分区：
文献类型：
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作者：
M. Sampaio;L. M. Pastrana-Martínez;Adrián M. T. Silva;J. G. Buijnsters;Changseok Han;Cláudia G. Silva;S. Carabineiro;D. Dionysiou;J. Faria
二氧化钛（TiO2）在光催化降解蓝藻毒素方面得到了广泛的研究。为了开发更高效的光催化剂，将TiO2与氧化纳米金刚石（NDox）组合为复合催化剂（NDox - TiO2），对淡水中常见的蓝藻毒素微囊藻毒素- la （MC-LA）进行了光催化氧化实验。采用液相沉积法制备了NDox-TiO2光催化剂和纯TiO2光催化剂。利用氮的物理吸附、x射线衍射（XRD）、UV-Vis和IR漫反射光谱（DRUV-Vis和DRIFT）、x射线光电子能谱（XPS）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）等多种分析技术对材料进行了表征。研究了光催化剂在模拟太阳光和可见光下的性能。动力学结果表明，NDox-TiO2复合材料在模拟太阳光照下的效率显著，与纯TiO2相比，协同因子大于15，而在可见光下使用NDox-TiO2降解MC-LA的光催化活性可以忽略不计，因为复合材料的带隙较宽。NDox - TiO2的光催化效率归因于两相在复合材料中的良好分散，促进了NDox和TiO2异质结界面上可能的电子相互作用。
Titanium dioxide (TiO2) has been under intensive investigation for photocatalytic degradation of cyanobacterial toxins. In order to develop more efficient photocatalysts, TiO2 and oxidized nanodiamonds (NDox) were combined as a composite catalyst (NDox–TiO2), which was tested in the photocatalytic oxidation of microcystin-LA (MC-LA), a cyanotoxin frequently found in freshwater. NDox–TiO2 and neat TiO2 photocatalysts were prepared by a liquid phase deposition method. A wide variety of analytical techniques, including physical adsorption of nitrogen, X-ray diffraction (XRD), UV-Vis and IR diffuse reflectance spectroscopies (DRUV-Vis and DRIFT), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), were used to characterize the materials. The performance of the photocatalysts was studied under both simulated solar and visible light. The kinetic results show remarkable efficiency for the NDox–TiO2 composite under simulated solar light irradiation with a synergistic factor of more than 15 relative to neat TiO2, while negligible photocatalytic activity was observed for the degradation of MC-LA when NDox–TiO2 was used under visible light illumination due to the wide band gap of the composite material. The photocatalytic efficiency of NDox–TiO2 was ascribed to the good dispersion of both phases in the composite material, facilitating the possible electronic interaction at the heterojunction interface between NDox and TiO2.