Peng Guiming, Ellis James E, Xu Gang, Xu Xueqing, Star Alexander
School of Metallurgy and Chemical Engineering, Jiangxi University of Science and Technology , Ganzhou 341000, China.
Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
ACS Appl Mater Interfaces. 2016 Mar 23;8(11):7403-10. doi: 10.1021/acsami.6b01188. Epub 2016 Mar 10.
Titanium dioxide (TiO2) nanostructures and TiO2/graphene nanocomposites are intensively studied materials for energy conversion, energy storage, and organic contaminant photodegradation. However, for TiO2/graphene composites, impermeability across the graphitic basal plane for electrolytes, metal ions, and gas molecules hinders their practical applications. Herein we report a simple, environmentally friendly synthetic route for mesoporous anatase TiO2 nanospindles, and successfully apply this method to obtain in situ grown TiO2 nanospindles/graphene oxide composite. After a thermal reduction at 400 °C, holes are created in the reduced graphene oxide (RGO) sheets through a photocatalytic oxidation mechanism. The formation of holes in RGO is promoted by photogenerated hydroxyl radicals that oxidize and subsequently decarboxylate the graphitic surface of RGO. The proposed mechanism was supported by photocatalytic electrochemical properties of the nanomaterials. The resulting TiO2/holey RGO composites may overcome the original impermeability of graphene sheets and find applications in catalysis, energy conversion/storage devices, and sensors.
二氧化钛（TiO₂）纳米结构及TiO₂/石墨烯纳米复合材料是用于能量转换、能量存储和有机污染物光降解的热门研究材料。然而，对于TiO₂/石墨烯复合材料而言，电解质、金属离子和气体分子在石墨基面的不可渗透性阻碍了它们的实际应用。在此，我们报道了一种简单、环保的合成介孔锐钛矿型TiO₂纳米纺锤体的路线，并成功应用该方法制备了原位生长的TiO₂纳米纺锤体/氧化石墨烯复合材料。在400℃进行热还原后，通过光催化氧化机制在还原氧化石墨烯（RGO）片层上形成了孔洞。RGO中孔洞的形成是由光生羟基自由基促进的，这些自由基氧化并随后使RGO的石墨表面脱羧。所提出的机制得到了纳米材料光催化电化学性质的支持。所得的TiO₂/多孔RGO复合材料可能会克服石墨烯片层原有的不可渗透性，并在催化、能量转换/存储装置及传感器领域找到应用。
