Heterogeneous Electron Transfer at Polyoxometalate-modified Electrode Surfaces

Bulletin of the Korean chemical society

Jongwon Kim¹  Bora Seo¹  Suhee Choi¹ 

关键词: Electron transfer;    Polyoxometalate;    Glassy carbon;    Au;    HOPG;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

The heterogeneous electron transfer at SiMo₁₂O₄₀^4? monolayers on GC, HOPG, and Au electrode surfaces are investigated using cyclic voltammetric and electrochemical impedance spectroscopic (EIS) methods. The electron transfer of negatively charged Fe(CN)₆^3? species is retarded at SiMo₁₂O₄₀^4? -modified electrode surfaces, while that of positively charged Ru(NH₃)₆³⁺species is accelerated at the modified surfaces. This is due to the electrostatic interactions between SiMo₁₂O₄₀^4? layers on surfaces and charged redox species. The electron transfer kinetics of a neutral redox species, 1,1�?- ferrocenedimethanol (FDM), is not affected by the modification of electrode surfaces with SiMo₁₂O₄₀^4?, indicating the SiMo₁₂O₄₀^4? monolayers do not impart barriers to electron transfer of neutral redox species. This is different from the case of thiolate SAMs which always add barriers to electron transfer. The effect of SiMo₁₂O₄₀^4? layers on the electron transfer of charged redox species is dependent on the kind of electrodes, where HOPG surfaces exhibit marked effects. Possible mechanisms responsible for different electron transfer behaviors at SiMo₁₂O₄₀^4? layers are proposed.

【 授权许可】

Unknown