Effects of Solvent Molecules on the Interlayer Spacing of Graphene Oxide

Abstract

Graphene oxide (GO) contains numerous functional groups that facilitate the intercalation of polar solvents. The properties and applications of GO are closely related to its interlayer spacing. We report on the changes in the interlayer spacing of GO after the adsorption of water molecules and the polar organic solvents C 2 H 6 O 2 (EG), C 3 H 7 NO (DMF), C 5 H 9 NO (NMP). Experiments were conducted to investigate the variations in the functional groups and structure of GO after solvent adsorption, and they play a vital role in modeling and verifying the results of molecular dynamics simulation. The most stable GO structures are obtained through molecular dynamics simulation. The expansion of the interlayer spacing of GO after the adsorption of monolayer solvent molecules corresponds to the minimum three-dimensional size of the solvent molecules. The spatial arrangement of solvent molecules also contributes to the changes in interlayer spacing. Most adsorbed molecules are oriented parallel to the carbon plane of GO. However, as additional molecules are adsorbed into the interlaminations of GO, the adsorbed molecules are oriented perpendicular to the carbon plane of GO, and a large space forms between two GO interlayers. In addition, the role of large molecules in increasing interlayer spacing becomes more crucial than that of water molecules in the adsorption of binary solvent systems by GO.

Layered Metal Oxide Nanosheets with Enhanced Interlayer Space for Electrochemical Deionization

“…[ 23–25 ] For typical layered materials such as graphene and LDHs, enlarging the interlayer distance is indispensable for facilitating the insertion of electrolyte ions, and improving ion diffusion kinetics in the field of energy storage. [ 26–30 ] In our previous work, the regulation of NiCo‐LDH interlayer spacing with acetate anion was explored and the NiCo‐LDH electrode with enlarged interlayer spacing exhibited ultrahigh specific capacity and excellent structural stability. [ 31 ] Therefore, inspired by the outstanding performance of LDHs with expanded interlayer spacing in energy storage applications, [ 31–33 ] we chose sodium dodecyl sulfate (SDS) to intercalate CoAl‐LDH (CoAl‐LDH‐SDS) using a hydrothermal method, and CoAl‐LMO‐SDS was obtained by additional heat treatment, as shown in Figure a.…”

Study on adsorption of methylene blue by a novel composite material of TiO2 and alum sludge

“…Methylene blue is an organic compound widely added to chemical indicators, 24–26 dyes and biological dyes, etc. In the dye wastewater, it is usually one of the most toxic substances 27,28 discharged into natural water bodies, as it will affect the growth of plants and animals and threaten the safety of human drinking water, and is found in sewage, rivers and soils.…”

Self‐Adhesive Polyimide (PI)@Reduced Graphene Oxide (RGO)/PI@Carbon Nanotube (CNT) Hierarchically Porous Electrodes: Maximizing the Utilization of Electroactive Materials for Organic Li‐Ion Batteries

“…Clearly, there is a sharp and strong diffraction peak located at about 11° (2 θ ) observed in GO, indicating that the layer spacing of GO is expanded to 0.803 nm due to the insertion of oxygen‐containing functional groups, which is calculated by the Bragg equation. [ 12 ] The expanded spacing enables the monomers and polymers to adhere easily to the GO layers, [ 13 ] improving the dispersibility in the polymer matrix. After being reduced at 450 °C, the diffraction peak at 11° (2 θ ) disappears, while a new peak at 25° (2 θ ) appears, indicating the layer spacing is about 0.356 nm, close to the layer space of graphite (0.335 nm), which means that the layer space decreases after the reduction process due to the disappearance of oxygen‐containing functional groups (such as OH and COOH).…”