title: Scan-rate-dependent current rectification of cone-shaped silica nanopores in quartz nanopipettes.
abstract: Here we report the voltammetric behavior of cone-shaped silica nanopores in quartz nanopipettes in aqueous solutions as a function of the scan rate, v. Current rectification behavior for silica nanopores with diameters in the range 4-25 nm was studied. The rectification behavior was found to be strongly dependent on the scan rate. At low scan rates (e.g., v < 1 V/s), the rectification ratio was found to be at its maximum and relatively independent of v. At high scan rates (e.g., v > 200 V/s), a nearly linear current-voltage response was obtained. In addition, the initial voltage was shown to play a critical role in the current-voltage response of cone-shaped nanopores at high scan rates. We explain this v-dependent current-voltage response by ionic redistribution in the vicinity of the nanopore mouth.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Guerrette
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
mesh_terms: D004553:Electric Conductivity; D004563:Electrochemistry; D058608:Nanopores; D011791:Quartz; D012822:Silicon Dioxide / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D011791:Quartz; D012822:Silicon Dioxide