Probing the sensing property of ice nanotubes toward atmospheric gas

Ice nanotubes (INTs) may stand out as a candidate for use as a gas sensing material due to their inherent properties. Accordingly, to explore the feasibility of using INTs as gas sensor, the adsorption of various atmospheric gas molecules including O2, N2, H2, CO2, CH4, and NH3 on the surface of pentagonal and hexagonal INTs was studied. We have provided detailed information on the equilibrium positions, adsorption energies, charge transfers, and topological parameters of the resultant complexes. It was found that INTs are reactive toward these molecules, however, due to the weak interactions for all studied gas molecules except O2, the adsorption leaves the electronic properties of INTs unaffected. Interestingly, the interaction of O2 molecule with INT induces dramatic changes to electronic structures of INTs which is accompanied by the band gap closure of about 76%, suggesting the sensitivity of INT-based sensors toward O2 adsorption.