New Structural Insights into Densely Assembled Reduced Graphene Oxide Membranes. (8th April 2022)

• Record Type: Journal Article
• Authors: Cao, Yang; Xiong, Zhiyuan; Xia, Fang; Franks, George V.; Zu, Lianhai; Wang, Xiao; Hora, Yvonne; Mudie, Stephen; He, Zijun; Qu, Longbing; Xing, Yanlu; Li, Dan
• Is Part Of: Advanced functional materials. Volume 32:Number 42(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-08
• Subjects: 2D assemblies -- 2D laminar membrane structures -- ion transportation pathways -- reduced graphene oxide membranes -- supercapacitors; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202201535
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: Densely assembled graphene‐based membranes have attracted substantial interest for their widespread applications, such as compact capacitive energy storage, ion/molecular separation, gas barrier films, and flexible electronics. However, the multiscale structure of densely packed graphene membranes remains ambiguously understood. This article combines X‐ray and light scattering techniques as well as dynamic electrosorption analysis to uncover the stacking structure of the densely stacked reduced graphene oxide (rGO) membranes. The membranes are produced by reducing graphene oxide (GO) membranes with hydrazine, during which the colloidal interactions between GO sheets are modulated by the electrolyte solution. In contrast to the common notion that direct reduction of densely assembled GO sheets in parallel tends to result in significant "graphitization", this article unexpectedly discovers that the resultant densely packed rGO membrane can still retain the interconnected network nanochannels and show good capacitive performances. This inspires the development of a hierarchical structural model to describe the densely packed rGO membranes. This article further shows that the nanochannel network can be fine‐tuned at the sub‐nanometer level by tailoring the salt concentration and the reduction temperature to render exceptional volumetric capacitance and good rate performance for rGO membranes even with increased packing density. Abstract : A new structure insight of the ultra‐dense reduced graphene oxide (rGO) membrane is revealed by the model system of hydrazine deoxygenated rGO membrane in the electrolyte. Their nanostructure is fine‐tuned to render exceptional volumetric capacitance and rate performances.