ナノ細孔流路を用いたMoS2表面電荷特性の評価

抄録

We evaluated the surface charge properties of a 3nm monolayer molybdenum disulfide (MoS₂) nanopore, exposed to a potassium chloride (KCl) aqueous solution, by measuring the ionic current as an external electric potential bias was applied across it. It was indicated that the ionic current was governed by the surface conductance at low concentrations as the electric double layer was thicker than/comparable to the pore radius. As a result, the ionic current was largely independent of the salt concentration when it was lower than 0.05 M (where the Debye length was close to 1.5 nm) consistent with the electric double layer theory. Furthermore, by considering a site-bonding model we estimated the equilibrium constant (pK=6) and number density ( =1/nm²) of surface functional groups on MoS2 in aqueous solutions. The acquired information can be useful for plenty of nanopore applications.