Mesopore-aspect-ratio dependence of ion transport in rodtype ordered mesoporous carbon

Abstract

The ion transport behavior in hexagonal ordered mesoporous carbon (OMC, two-dimensional mesopore symmetry) materials with diverse mesopore diameter and length was studied by evaluating the dynamic process of inner-pore electric double layer formation. Scanning electron microscopy and nitrogen cryo-sorption methods were used to probe the mesopore characteristics of these OMC materials and determine their aspect ratios (length/diameter). The interfacial capacitance of the inner-pore electric double layer was greatly decayed when shortening ion transport time by increasing the potential sweep rate of cyclic voltammetry or the alternative current frequency of electrochemical impedance spectroscopy. The better ion transport behavior in mesopores with smaller mesopore aspect ratio was obtained. © 2008 American Chemical Society.