Potential dependence of the structure of water at the hydrophobic liquid interface

Electrochemically Driven Reorientation of Three Ionic States of p-Aminobenzoic Acid on Ag(111)

“…49,50 However, the intensity zero for the background spectra plotted in Figure 3 extrapolates to -2.4 V vs Ag/AgCl at pH ) 1.4, which is far away from the measured value of -0.68 V vs Ag/AgCl for the PZC of Ag(111) in 0.1 M NaF. 39,51 The SFG results provide extrapolated intensity zero values at -3.9 and -3.7 V at pH ) 4.4 and pH ) 12.8, respectively, again far away from the measured value of the PZC. Thus, the intensity minima found in our SFG measurements are not at the PZC.…”

“…All cyclic voltammetry (CV) measurements were recorded at 100 mV/s unless otherwise stated, and interfacial capacitance values were calculated from impedance versus potential measurements (excitation frequency ω ) 25 Hz and an amplitude of 10 mV) according to a previously described method. 25,39,45 The spectroelectrochemical cell has been described previously. 33 Briefly, it consists of a glass/Kel-F base which is fixed to a 24.5 × 3 mm CaF 2 disk (Casix) that serves as the optical window.…”

“…Electrochemical measurements were carried out using CH Instruments potentiostats (Austin, TX) in a standard, two-compartment, glass cell. All cyclic voltammetry (CV) measurements were recorded at 100 mV/s unless otherwise stated, and interfacial capacitance values were calculated from impedance versus potential measurements (excitation frequency ω = 25 Hz and an amplitude of 10 mV) according to a previously described method. ,, …”

“…Many techniques, theoretical and experimental, have been utilized to examine molecules on surfaces. ,− With regard to the molecular reorientation issue, comparisons between cyclic voltammograms and capacitive electrochemical techniques are particularly useful in distinguishing potential driven phase transitions of adsorbates. − More recently, the infrared visible sum frequency generation (SFG) technique has become very useful in examining electrode surfaces. ,,− SFG can report on the orientation state of the molecule as a function of applied potential via the phase difference between the molecule’s vibrational resonances and the nonresonant contribution from the electrode surface.…”

“…[33][34][35][36] More recently, the infrared visible sum frequency generation (SFG) technique has become very useful in examining electrode surfaces. 19,25,[37][38][39][40] SFG can report on the orientation state of the molecule as a function of applied potential via the phase difference between the molecule's vibrational resonances and the nonresonant contribution from the electrode surface.…”