This work focuses computationally on the role of graphene and graphene oxide nanosheets in improving the formation of methane gas hydrate and their potential as a promising alternative to traditional gas storage and transportation method. To evaluate methane gas mechanism storage between graphene and graphene oxide nanosheets including C8O-flat, C8O-polar, and C8(OH)2 surfaces, radial distribution function, mean squared displacement, number of hydrogen bonding, and coordination number were taken under consideration. Our results showed that methane hydrate is well formed between graphene, C8O-flat, and C8O-polar nanosheets. C8(OH)2 nanosheet has an inhibitory effect on the gas hydrate formation caused by the formation of hydrogen bonds between the hydroxyl functional groups of the sheets and water molecules. To further investigate the degree of hydrate formation, a four-body structural order (F4φ) was obtained. The values of the F4φ parameter for the C8O-flat, graphene, C8O-polar, and C8(OH)2 systems are 0.6, 0.55, 0.51, and ???? 0.02, respectively. These values indicate the presence of an almost complete and regular network of methane hydrate between the first three mentioned sheets. However, the negative value of the F4φ parameter in the last one suggests the absence of significant hydrate formation by ice-like structure of water molecules. The effect of different temperatures on the formation of methane hydrate was also investigated. It is observed that the hydrate structure completely breaks down in the range of 300–400 K in the different structures.

Keywords