title: Potentiometric Measurements of Semiconductor Nanocrystal Redox Potentials.
abstract: A potentiometric method for measuring redox potentials of colloidal semiconductor nanocrystals (NCs) is described. Fermi levels of colloidal ZnO NCs are measured in situ during photodoping, allowing correlation of NC redox potentials and reduction levels. Excellent agreement is found between electrochemical and optical redox-indicator methods. Potentiometry is also reported for colloidal CdSe NCs, which show more negative conduction-band-edge potentials than in ZnO. This difference is highlighted by spontaneous electron transfer from reduced CdSe NCs to ZnO NCs in solution, with potentiometry providing a measure of the inter-NC electron-transfer driving force. Future applications of NC potentiometry are briefly discussed.
authors.affiliation: Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
authors.forename: Gerard M
authors.initials: GM
authors.lastname: Carroll
authors.affiliation: Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
authors.forename: Carl K
authors.initials: CK
authors.lastname: Brozek
authors.affiliation: Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
authors.forename: Kimberly H
authors.initials: KH
authors.lastname: Hartstein
authors.affiliation: Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
authors.forename: Emily Y
authors.initials: EY
authors.lastname: Tsui
authors.affiliation: Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Gamelin
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry; D004579:Electron Transport; D053758:Nanoparticles / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry; D010084:Oxidation-Reduction; D011199:Potentiometry; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry; D012666:Semiconductors; D015034:Zinc Oxide / Q000032:analysis
chemical_list: D019187:Cadmium Compounds; D018036:Selenium Compounds; D015034:Zinc Oxide