2016/01/06 by Shulai Lei, Shujuan Li, Lei, Shulai +5
Engineering · Materials Science · Physics and Astronomy · #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Graphene research and applications #Nanopore and Nanochannel Transport Studies #Quantum and electron transport phenomena #physics.chem-ph
paper · pdf · doi:10.48550/arxiv.1601.01346
19 pages, 5 figures
arxiv created 2016/01/06 · openalex publication_date 2016/01/06 · arxiv updated 2016/01/08 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The curvature dependence of the physisorption properties of a water molecule inside and outside an armchair carbon nanotube (CNTs) is investigated by an incremental density-fitting local coupled cluster treatment with single and double excitations and perturbative triples (DF-LCCSD(T)) study. Our results show that a water molecule outside and inside (n, n) CNTs (n=4, 5, 6, 7, 8, 10) is stabilized by electron correlation. The adsorption energy of water inside CNTs decreases quickly with the decrease of curvature (increase of radius) and the configuration with the oxygen pointing towards the CNT wall is the most stable one. However, when the water molecule is adsorbed outside the CNT, the adsorption energy varies only slightly with the curvature and the configuration with hydrogens pointing towards the CNT wall is the most stable one. We also use the DF-LCCSD(T) results to parametrize Lennard-Jones (LJ) force fields for the interaction of water both with the inner and outer sides of CNTs and with graphene representing the zero curvature limit. It is not possible to reproduce all DF-LCCSD(T) results for water inside and outside CNTs of different curvature by a single set of LJ parameters, but two sets have to be used instead. Each of the two resulting sets can reproduce three out of four minima of the effective potential curves reasonably well. These LJ models are then used to calculate the water adsorption energies of larger CNTs, approaching the graphene limit, thus bridging the gap between CNTs of increasing radius and flat graphene sheets.