Two-phase hydrothermal synthesis of TiO2-graphene hybrids with improved photocatalytic activity
Two-phase hydrothermal synthesis of TiO2-graphene hybrids with improved photocatalytic activity
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DOI：
10.1016/j.jallcom.2013.03.283
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发表时间：
2013-09
影响因子：
6.2
通讯作者：
Dafeng Zhang;Xipeng Pu;Guqiao Ding;X. Shao;Yanyan Gao;Jian-xiu Liu;Meichao Gao;Y. Li
中科院分区：
文献类型：
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作者：
Dafeng Zhang;Xipeng Pu;Guqiao Ding;X. Shao;Yanyan Gao;Jian-xiu Liu;Meichao Gao;Y. Li
采用简单的两相水热法一锅法合成了TiO 2-石墨烯杂化材料（TGHs）。采用X射线衍射、傅里叶变换红外光谱、热重和差示扫描量热法、透射电子显微镜、拉曼光谱、X射线光电子能谱、漫反射吸收光谱、比表面积和光致发光等方法对样品的结构、形貌和光催化降解甲基橙子的性能进行了表征。实验结果表明，该方法可以同时实现TiO 2的合成、氧化石墨烯的还原以及二者的复合。与纯TiO 2、商业P25和通过单相（水）方法合成的TGH相比，合成的TGH显示出改善的光降解性能。TGHs光降解性能的改善归因于光生电子从TiO 2到石墨烯的有效转移抑制了电子和空穴的复合。此外，在两相体系中，样品在水和氯仿之间的相转移对TGHs光催化性能的提高起着至关重要的作用，因为通过相转移可以有效地阻止TGHs的聚集，从而获得更高的比表面积和优异的吸附能力，改善其光催化性能。
TiO2–graphene hybrids (TGHs) were one-pot synthesized by a simple two-phase hydrothermal method, without the synthesis of TiO2in advance. The structures, morphologies, and photocatalytic properties of samples for methyl orange were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry and differential scanning calorimetry, transmission electron microscopy, Raman spectrum, X-ray photoelectron spectroscopy, diffuse reflectance absorption spectrum, specific surface area, and photoluminescence. Experimental results show that the synthesis of TiO2, reduction of graphene oxide, and combination of them were realized simultaneously. The as-synthesized TGHs showed improved photodegradation performances compared to neat TiO2, commercial P25, and TGH synthesized by a single-phase (water) method. The improved photodegradation performances of TGHs are attributed to the suppressed recombination of electrons and holes caused by the effective transfer of photo-generated electrons from TiO2to graphene. Moreover, the phase transfer of sample between the water and the chloroform in the two-phase system plays a crucial role in the enhancement of photocatalytic performances of TGHs, because through the phase transfer the aggregation of TGHs can be effectively hindered, leading to higher specific surface area, excellent adsorption capacity, and improved photocatalytic properties.