To what extent can mutual shifting of folded carbonaceous walls in slit-like pores affect their adsorption properties?

Abstract

We have performed systematic Monte Carlo studies on the influence of shifting the walls in slit-like systems constructed from folded graphene sheets on their adsorption properties. Specifically, we have analysed the effect on the mechanism of argon adsorption (T = 87 K) and on adsorption and separation of three binary gas mixtures: CO2/N2, CO2/CH4 and CH4/N2 (T = 298 K). The effects of the changes in interlayer distance were also determined. We show that folding of the walls significantly improves the adsorption and separation properties in comparison to ideal slit-like systems. Moreover, we demonstrate that mutual shift of sheets (for small interlayer distances) causes the appearance of small pores between opposite bulges. This causes an increase in vapour adsorption at low pressures. Due to overlapping of interactions with opposite walls causing an increase in adsorption energy, the mutual shift of sheets is also connected with the rise in efficiency of mixture separation. The effects connected with sheet orientation vanish as the interlayer distance increases.

The effects of confinement in pores built of folded graphene sheets on the equilibrium of nitrogen monoxide dimerisation reaction

“…Clearly, structural and chemical heterogeneities affect the properties of graphene and graphene-related materials [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. The existence of curved graphene structures was discussed in our earlier works [36,37]. The folding of carbonaceous sheets transforms the 2D material into the 3D one [38,39].…”

“…In our previous work, we have developed an in-silico computational methodology for generation of the structural atomistic models of folded graphene sheets [36]. The energetically stable corrugated graphene sheets were used for construction of the atomistic structural models of slit-like porous systems [36,37]. The simulations of gas adsorption and separations in such models consisting of morphologically disordered slit-shaped carbon pores [36,37] revealed their significant advantage compared to structural atomistic models consisting of networks of ideal flat graphene sheets.…”

“…The energetically stable corrugated graphene sheets were used for construction of the atomistic structural models of slit-like porous systems [36,37]. The simulations of gas adsorption and separations in such models consisting of morphologically disordered slit-shaped carbon pores [36,37] revealed their significant advantage compared to structural atomistic models consisting of networks of ideal flat graphene sheets. The advantages related to the curvature of graphene sheets in specific applications were also shown by others [27,40,41].…”

“…The main aim of the current study is to examine how the folding of graphene sheets affects the chemical reaction equilibria. We have used series of porous networks consisting of corrugated sheets-as it has been mentioned above, such model adsorbents were used by us earlier to study other phenomena [36,37]. These atomistic models allow to systematically determine the relationships between the composition of reacting mixture and different structural parameters, such as the degree of folding, the interlayer distance and the mutual orientation of sheets.…”

Gyroidal nanoporous carbons - Adsorption and separation properties explored using computer simulations

“…We used Ar adsorption isotherm simulated in the ideal slitlike system composed of graphene sheets with effective pore width equal to 10 nm as the reference one. We also determined the values of Henry's constant (K H ) from the slope of the linear part of adsorption isotherms in the low-pressure range [83]. Finally, adsorption potential distribution (APD) curves [93][94][95] were calculated.…”