Abstract Facile electron-hole recombination and the broad band gap are two major bottlenecks of titanium dioxide (TiO2) applied in visible-light photocatalysis. Hybridization of TiO2 with graphene is a promising strategy to alleviate these drawbacks. In this paper, we demonstrate a novel technique to synthesize TiO2/graphene nanocomposites without the use of graphene oxide (GO). Graphene dispersion was obtained through the chemical exfoliation of graphite in titanium tetra-n-butoxide by ultrasonication. The dispersion was directly used for the sol-gel reaction in the presence of different catalysts, affording TiO2/graphene nanocomposites featured with several advantages: i) the formation of a TiO2 nano layer that uniformly and thinly covered graphene sheets, ii) a trace amount of defects on graphene sheets, iii) a significant extension of the absorption edge into the visible light region, and iv) a dramatic suppression of electron-hole recombination. When tested for methylene blue decomposition under visible light, our nanocomposites exhibited the photocatalytic activity 15 and 5 times greater than that of TiO2-P25 and a conventional GO-based nanocomposite, respectively.

中文翻译：

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基于化学剥离法的一锅法合成TiO 2 /石墨烯纳米复合材料具有优异的可见光光催化性能

摘要 容易的电子-空穴复合和宽带隙是二氧化钛（TiO2）应用于可见光光催化的两大瓶颈。TiO2 与石墨烯的杂交是缓解这些缺点的一种很有前景的策略。在本文中，我们展示了一种在不使用氧化石墨烯（GO）的情况下合成 TiO2/石墨烯纳米复合材料的新技术。石墨烯分散体是通过超声处理在四正丁醇钛中对石墨进行化学剥离而获得的。该分散体在不同催化剂存在下直接用于溶胶-凝胶反应，提供了具有以下几个优点的 TiO2/石墨烯纳米复合材料：i) 形成均匀且薄薄地覆盖石墨烯片的 TiO2 纳米层，ii) 微量石墨烯片上的缺陷，iii) 吸收边显着扩展到可见光区域，以及 iv) 显着抑制电子-空穴复合。在可见光下测试亚甲基蓝分解时，我们的纳米复合材料的光催化活性分别比 TiO2-P25 和传统的 GO 基纳米复合材料高 15 倍和 5 倍。