Synthesis of fullerene-, carbon nanotube-, and graphene-TiO₂ nanocomposite photocatalysts for selective oxidation: a comparative study.
Synthesis of fullerene-, carbon nanotube-, and graphene-TiO₂ nanocomposite photocatalysts for selective oxidation: a comparative study.
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DOI：
10.1021/am3029798
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发表时间：
2013-01
影响因子：
9.5
通讯作者：
Min‐Quan Yang;N. Zhang;Yi‐Jun Xu
中科院分区：
文献类型：
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作者：
Min‐Quan Yang;N. Zhang;Yi‐Jun Xu
采用溶胶-凝胶法和水热法相结合的方法制备了一系列不同碳含量配比的纳米TiO 2-石墨烯（GR）、纳米碳管（CNT）和富勒烯（C（60））复合光催化剂。通过X射线衍射（XRD）、紫外可见漫反射光谱（DRS）、透射电子显微镜（TEM）、氮吸附-脱附和光电化学测试确定了它们的结构和性能。以苯甲醇光催化选择氧化制苯甲醛为模型反应，研究了TiO（2）-碳（GR，CNT，C（60））纳米复合材料在可见光照射下的光催化活性.结果表明，碳材料与TiO（2）的复合可以使TiO（2）-碳纳米复合材料的吸附边界扩展到可见光区。对于TiO（2）-GR、TiO（2）-CNT和TiO（2）-C（60）纳米复合材料，最佳配比为TiO（2）-0.1%GR、TiO（2）-0.5%CNT和TiO（2）-1.0%C（60）的复合材料的光催化活性随照射时间的变化沿着非常接近。此外，采用不同的自由基清除技术对TiO（2）-碳纳米复合材料光催化选择氧化苯甲醇制备苯甲醛的反应机理进行了研究，表明TiO（2）-碳纳米复合材料光催化选择氧化苯甲醇遵循类似的氧化机理.不同碳材料的加入对TiO（2）的晶相、粒径和形貌无明显影响。因此，可以得出结论，至少对于通过本方法获得的TiO（2）-碳（GR、CNT和C（60））的纳米复合材料，这三种不同的碳同素异形体GR、CNT和C（60）在影响半导体TiO（2）的光催化性能方面本质上没有太大差异。我们的研究结果表明，对石墨烯-碳光催化剂进行比较研究，得出相对客观的结论，而不是单独强调GR的独特作用，加入石墨烯淘金热。
A series of TiO(2)-graphene (GR), -carbon nanotube (CNT), and -fullerene (C(60)) nanocomposite photocatalysts with different weight addition ratios of carbon contents are synthesized via a combination of sol-gel and hydrothermal methods. Their structures and properties are determined by the X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), transmission electron microscopy (TEM), nitrogen adsorption-desorption, and photoelectrochemical measurements. Photocatalytic selective oxidation of benzyl alcohol to benzaldehyde is employed as a model reaction to evaluate the photocatalytic activity of the TiO(2)-carbon (GR, CNT, and C(60)) nanocomposites under visible light irradiation. The results reveal that incorporating TiO(2) with carbon materials can extend the adsorption edge of all the TiO(2)-carbon nanocomposites to the visible light region. For TiO(2)-GR, TiO(2)-CNT, and TiO(2)-C(60) nanocomposites, the photocatalytic activities of the composites with optimum ratios, TiO(2)-0.1% GR, TiO(2)-0.5% CNT, and TiO(2)-1.0% C(60), are very close to each other along with the irradiation time. Furthermore, the underlying reaction mechanism for the photocatalytic selective oxidation of benzyl alcohol to benzaldehyde over TiO(2)-carbon nanocomposites has been explored using different radical scavenger techniques, suggesting that TiO(2)-carbon photocatalysts follow the analogous oxidation mechanism toward selective oxidation of benzyl alcohol. The addition of different carbon materials has no significant influence on the crystal phase, particle size, and the morphology of TiO(2). Therefore, it can be concluded, at least for nanocomposites of TiO(2)-carbon (GR, CNT, and C(60)) obtained by the present approach, that there is no much difference in essence on affecting the photocatalytic performance of semiconductor TiO(2) among these three different carbon allotropes, GR, CNT, and C(60). Our findings point to the importance of a comparative study of semiconductor-carbon photocatalysts on drawing a relatively objective conclusion rather than separately emphasizing the unique role of GR and joining the graphene gold rush.