Pseudohalogens for Dye-Sensitized TiO2 Photoelectrochemical Cells

作者：Gerko Oskam, Bryan V. Bergeron, Gerald J. Meyer, Peter C. Searson · 发表于：The Journal of Physical Chemistry B · 年份：2001 · DOI：10.1021/jp004411d · 被引用次数：382 · 研究领域：TiO2 Photocatalysis and Solar Cells、Electrochemical Analysis and Applications、Analytical Chemistry and Sensors

In this paper, we report on the preparation and characterization of two pseudohalogen redox couples for dye-sensitized TiO 2 photoelectrochemical cells. The equilibrium potentials of the (SeCN) 2 /SeCN - and (SCN) 2 /SCN - couples are respectively 0.19 and 0.43 V more positive than for the I 3 - /I - couple, providing the opportunity to determine the influence of the redox potential on the open circuit photovoltage. With the sensitizer cis -Ru(dcb) 2 (NCS) 2 (N3), the incident photon-to-current conversion efficiency was 20% for the (SeCN) 2 /SeCN - couple and 4% for the (SCN) 2 /SCN - couple. Transient absorbance measurements showed that the quantum yield for electron injection is independent of the pseudohalogen redox couple and that the regeneration rates of the dye decrease in the order I - > SeCN - > SCN - . The effects of the redox potential on open circuit photovoltage were determined by independent measurement of the dependence of the sensitized TiO 2 working electrode and the platinum counter electrode potentials on the cell voltage.