Chemical and Life Sciences & Engineering Division, Water Desalination and Reuse Center, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.
Nanoscale. 2012 Nov 21;4(22):7038-45. doi: 10.1039/c2nr32157b.
In this study, three-dimensional (3D) graphene assemblies are prepared from graphene oxide (GO) by a facile in situ reduction-assembly method, using a novel, low-cost, and environment-friendly reducing medium which is a combination of oxalic acid (OA) and sodium iodide (NaI). It is demonstrated that the combination of a reducing acid, OA, and NaI is indispensable for effective reduction of GO in the current study and this unique combination (1) allows for tunable control over the volume of the thus-prepared graphene assemblies and (2) enables 3D graphene assemblies to be prepared from the GO suspension with a wide range of concentrations (0.1 to 4.5 mg mL(-1)). To the best of our knowledge, the GO concentration of 0.1 mg mL(-1) is the lowest GO concentration ever reported for preparation of 3D graphene assemblies. The thus-prepared 3D graphene assemblies exhibit low density, highly porous structures, and electrically conducting properties. As a proof of concept, we show that by infiltrating a responsive polymer of polydimethylsiloxane (PDMS) into the as-resulted 3D conducting network of graphene, a conducting composite is obtained, which can be used as a sensing device for differentiating organic solvents with different polarity.
在这项研究中，通过一种简便的原位还原-组装方法，使用新型、低成本且环保的还原介质，即草酸（OA）和碘化钠（NaI）的组合，从氧化石墨烯（GO）制备了三维（3D）石墨烯组装体。结果表明，在本研究中，还原酸 OA 和 NaI 的组合对于 GO 的有效还原是必不可少的，这种独特的组合（1）允许对所制备的石墨烯组装体的体积进行可调控制，（2）能够从浓度范围很宽的 GO 悬浮液（0.1 至 4.5mg/mL）制备 3D 石墨烯组装体。据我们所知，GO 浓度为 0.1mg/mL 是迄今为止报道的用于制备 3D 石墨烯组装体的最低 GO 浓度。所制备的 3D 石墨烯组装体具有低密度、高度多孔的结构和导电性能。作为概念验证，我们展示了通过将响应性聚合物聚二甲基硅氧烷（PDMS）渗透到所得的 3D 石墨烯导电网络中，可以获得一种导电复合材料，该复合材料可用作区分不同极性有机溶剂的传感装置。
