Effect of the Surface Termination on the Adsorption of Flue Gas by the Ti2ct2 Mxene

17 Pages Posted: 6 Oct 2022

See all articles by José D. Gouveia

José D. Gouveia

Universidade de Aveiro

José R. B. Gomes

Universidade de Aveiro

Abstract

Depending on the synthesis and/or post-treatment method, MXenes become covered by surface terminations. Here, we investigate how suitable the Ti2C MXene, with 9 different termination possibilities (none, Br, Cl, F, H, NH, O, OH or S), is for adsorbing 12 flue gas molecules, namely, CH4, CO, CO2, H2, H2O, H2S, N2, NH3, NO, O2, SO2 and SO3. According to our results, a general rule is that stronger adsorption is associated to more charge transferred between the adsorbent and the adsorbate. The clean Ti2C MXene is very reactive and spontaneously dissociates nearly half the species considered. H and F surface terminations are easily replaced by O in the presence of an atmosphere containing O2 since its dissociation on Ti2CH2 or Ti2CF2 is energetically cheap and exothermic. The Ti2C(OH)2 surface is damaged by the adsorption of NO, O2, SO2 or SO3 because they bind the hydroxyl’s H atoms and locally create O terminations. Ti2CO2 and Ti2CS2 are selective towards the chemisorption of NH3 and NO, respectively, with adsorption energies suitable for adsorption/separation applications. The Ti2CBr2, Ti2CCl2 and Ti2C(NH)2 surfaces physisorb all the investigated molecules, with binding energies that qualitatively correlate with their van der Waals volumes, thus having potential for sensing applications.

Keywords: MXenes, density functional simulations, flue gas, Adsorption, Sensing

Suggested Citation

Gouveia, José D. and Gomes, José R. B., Effect of the Surface Termination on the Adsorption of Flue Gas by the Ti2ct2 Mxene. Available at SSRN: https://ssrn.com/abstract=4239413 or http://dx.doi.org/10.2139/ssrn.4239413

José D. Gouveia

Universidade de Aveiro ( email )

José R. B. Gomes (Contact Author)

Universidade de Aveiro ( email )

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Downloads
59
Abstract Views
338
Rank
675,760
PlumX Metrics