Abstract
GaAs electrodes coated with hydrophobic, methyl-mercaptobiphenyl (CH 3-MBP) monolayers exhibited an excellent electrochemical stability. We found that the interface resistance of the chemically functionalized GaAs shows linear relationships with electrolyte pH and bias potential in a reproducible manner. The impedance spectra measured in a wide frequency range (f = 100 kHz to 50 mHz) are analyzed with several equivalent circuit models in a quantitative manner, and the pH sensitivity extrapolated from two linear relationships (35 mV pH-1) can be attributed to the absorption of the OH- ions on the hydrophobic surface.
Original language | English |
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Pages (from-to) | 12414-12419 |
Number of pages | 6 |
Journal | Journal of Physical Chemistry C |
Volume | 111 |
Issue number | 33 |
DOIs | |
State | Published - 23 Aug 2007 |
Externally published | Yes |