Carroll Gerard M, Brozek Carl K, Hartstein Kimberly H, Tsui Emily Y, Gamelin Daniel R
Department of Chemistry, University of Washington , Seattle, Washington 98195-1700, United States.
J Am Chem Soc. 2016 Apr 6;138(13):4310-3. doi: 10.1021/jacs.6b00936. Epub 2016 Mar 23.
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.
描述了一种用于测量胶体半导体纳米晶体(NCs)氧化还原电位的电位测定法。在光掺杂过程中对胶体ZnO NCs的费米能级进行原位测量,从而能够关联NC的氧化还原电位和还原水平。在电化学和光学氧化还原指示剂方法之间发现了极佳的一致性。还报道了胶体CdSe NCs的电位测定法,其导带边缘电位比ZnO中的更负。溶液中还原的CdSe NCs向ZnO NCs的自发电子转移突出了这种差异,电位测定法提供了NC间电子转移驱动力的一种度量。简要讨论了NC电位测定法的未来应用。