Hydrogenation-Assisted Graphene Origami and Its Application in Programmable Molecular Mass Uptake, Storage, and Release

The malleable nature of atomically thin graphene makes it a potential candidate material for nanoscale origami, a promising bottom-up nanomanufacturing approach to fabricating nanobuilding blocks of desirable shapes. The success of graphene origami hinges upon precise and facile control of graphene morphology, which still remains as a significant challenge. Inspired by recent progresses on functionalization and patterning of graphene, we demonstrate hydrogenation-assisted graphene origami (HAGO), a feasible and robust approach to enabling the formation of unconventional carbon nanostructures, through systematic molecular dynamics simulations. A unique and desirable feature of HAGO-enabled nanostructures is the programmable tunability of their morphology via an external electric field. In particular, we demonstrate reversible opening and closing of a HAGO-enabled graphene nanocage, a mechanism that is crucial to achieve molecular mass uptake, storage, and release. HAGO holds promise to enable an array of carbon nanostructures of desirable functionalities by design. As an example, we demonstrate HAGO-enabled high-density hydrogen storage with a weighted percentage exceeding the ultimate goal of US Department of Energy.原子级超薄石墨烯（atomically thin graphene）具备优异的可变形特性，使其成为纳米级折纸的潜在候选材料——纳米级折纸是一种极具前景的自下而上纳米制造方法，可用于制备具有理想形貌的纳米构建单元。石墨烯折纸的成功实现依赖于对石墨烯形貌精准且简便的调控，但目前这仍是一项重大挑战。受近期石墨烯功能化与图案化研究进展的启发，我们通过系统性分子动力学模拟，展示了氢化辅助石墨烯折纸（hydrogenation-assisted graphene origami，HAGO）：这是一种可行且稳健的方法，可实现非常规碳纳米结构的构建。HAGO制备的纳米结构的一项独特且极具应用价值的特性，是可通过外电场实现形貌的可编程可调性。具体而言，我们验证了HAGO制备的石墨烯纳米笼可实现可逆的开合行为，这一机制对于实现分子质量吸附、存储与释放至关重要。HAGO有望通过定制化设计，构建一系列具备理想功能的碳纳米结构。作为示例，我们展示了HAGO制备的高密度储氢体系，其储氢质量百分比超过了美国能源部（US Department of Energy）的终极目标。