Cao Yang, Xiong Zhiyuan, Liang Qinghua, Jiang Wen-Jie, Xia Fang, Du Xiaoyang, Zu Lianhai, Mudie Stephen, Franks George V, Li Dan
Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia.
Harry Butler Institute, Murdoch University, Perth, Western Australia 6150, Australia.
ACS Nano. 2023 Mar 14;17(5):5072-5082. doi: 10.1021/acsnano.3c00155. Epub 2023 Feb 17.
Assembling two-dimensional (2D) nanomaterials into laminar membranes with a subnanometer (subnm) interlayer spacing provides a material platform for studying a range of nanoconfinement effects and exploring the technological applications related to the transport of electrons, ions and molecules. However, the strong tendency for 2D nanomaterials to restack to their bulk crystalline-like structure makes it challenging to control their spacing at the subnm scale. It is thus necessary to understand what nanotextures can be formed at the subnm scale and how they can be engineered experimentally. In this work, with dense reduced graphene oxide membranes as a model system, we combine synchrotron-based X-ray scattering and ionic electrosorption analysis to reveal that their subnanometric stacking can result in a hybrid nanostructure of subnm channels and graphitized clusters. We demonstrate that the ratio of these two structural units, their sizes and connectivity can be engineered by stacking kinetics through the reduction temperature to allow the realization of high-performance compact capacitive energy storage. This work highlights the great complexity of subnm stacking of 2D nanomaterials and provides potential methods to engineer their nanotextures at will.
将二维（2D）纳米材料组装成具有亚纳米（subnm）层间距的层状膜，为研究一系列纳米限域效应以及探索与电子、离子和分子传输相关的技术应用提供了一个材料平台。然而，二维纳米材料强烈倾向于重新堆叠成其块状晶体状结构，这使得在亚纳米尺度上控制它们的间距具有挑战性。因此，有必要了解在亚纳米尺度上可以形成哪些纳米结构，以及如何通过实验对其进行设计。在这项工作中，以致密的还原氧化石墨烯膜作为模型系统，我们结合基于同步加速器的X射线散射和离子电吸附分析，揭示了它们的亚纳米堆叠可以产生亚纳米通道和石墨化簇的混合纳米结构。我们证明，通过还原温度控制堆叠动力学，可以设计这两个结构单元的比例、尺寸和连通性，从而实现高性能的紧凑型电容式能量存储。这项工作突出了二维纳米材料亚纳米堆叠的巨大复杂性，并提供了随意设计其纳米结构的潜在方法。
