Porous Characteristics of Three-Dimensional Disordered Graphene Networks

• Published in: Crystals (Basel) Vol. 11; no. 2; p. 127
• Main Authors: Wang, YongChao, Zhu, YinBo, Wu, HengAn
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-01-2021
• Subjects: Annealing; Carbon; Cluster analysis; Density; disordered graphene networks; Experiments; Graphene; Graphitization; High temperature; Hydrogen; Hydrogen storage; Low temperature; Morphology; Pore size; Pore size distribution; Porosity; porous characteristics; Porous materials; Simulation
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst11020127

The porous characteristics of disordered carbons are critical factors to their performance on hydrogen storage and electrochemical capacitors. Even though the porous information can be estimated indirectly by gas adsorption experiments, it is still hard to directly characterize the porous morphology considering the complex 3D connectivity. To this end, we construct full-atom disordered graphene networks (DGNs) by mimicking the chlorination process of carbide-derived carbons using annealing-MD simulations, which could model the structure of disordered carbons at the atomic scale. The porous characteristics, including pore volume, pore size distribution (PSD), and specific surface area (SSA), were then computed from the coordinates of carbon atoms. From the evolution of structural features, pores grow dramatically during the formation of polyaromatic fragments and sequent disordered framework. Then structure is further graphitized while the PSD shows little change. For the obtained DGNs, the porosity, pore size, and SSA increase with decreasing density. Furthermore, SSA tends to saturate in the low-density range. The DGNs annealed at low temperatures exhibit larger SSA than high-temperature DGNs because of the abundant free edges.