Electrochemical crystal Sauerbrey equation

The first application of the quartz crystal microbalance in electrochemistry came with the work of Bruckenstein and Shay (1985) who proved that the Sauerbrey equation could still be applied to a quartz wafer one side of which was covered with electrolyte. Although they were able to establish that an electrolyte layer several hundred angstroms thick moved essentially with the quartz surface, they also showed that the thickness of this layer remained constant with potential so any change in frequency could be attributed to surface film formation. The authors showed that it was possible to take simultaneous measurements of the in situ frequency change accompanying electrolysis at a working electrode (comprising one of the electrical contacts to the crystal) as a function of the applied potential or current. They coined the acronym EQCM (electrochemical quartz crystal microbalance) for the technique. 

The Electrochemical Quartz Crystal Microbalance (EQCM) The resonant frequency of a quartz crystal oscillator is perturbed from its base value (f ) by attached overlayers. For thin, rigid films the measured change in resonant frequency (Af) with attached mass (AM) is described by the Sauerbrey equation (10) ... 

Electrochemical quartz crystal microbalance (EQCM) is a powerful tool for elucidating interfacial reactions based on the simultaneous measurement of electrochemical parameters and mass changes at electrode surfaces. The microbalance is based on a quartz crystal wafer, which is sandwiched between two electrodes, used to induce an electric held (Fig. 2.21). Such a held produces a mechanical oscillation in the bulk of the wafer. Surface reactions, involving minor mass changes, can cause perturbation of the resonant frequency of the crystal oscillator. The frequency change (A/) relates to the mass change (Am) according to the Sauerbrey equation ... 

An electrochemical quartz crystal microbalance (EQCM) experiment was carried out to determine the mass change on the electrode. The equation of the resonant frequency change for mass change has been presented by the Sauerbrey equation ... 

Electrochemical quartz crystal microbalance. To monitor adsorbate accumulation on catalyst surfaces from formic acid electrooxidation and advance mechanistic understanding, an electrochemical quartz crystal microbalance (EQCM) can be used to simultaneously measure current and mass [22, 66, 81-83]. The dampening of the vibration frequency (A/) of an AT-cut 9 MHz piezoelectric crystal is directly proportional to mass accumulation (Am) on the catalyst surface through the Sauerbrey equation (A/ = —/o 2(jUqPq) Am/A) [84], where /o is the base... 

EQCM experiments were performed using an AT-cut quartz crystal disk, with a diameter of 12 mm and 10 MHz nominal frequency. Copper was deposited from an acidic copper bath (Muller, 1953). An electrochemical nanobalance system model EQCN-701 connected to a potentiostat model PS-205 (ELCHEMA, N.Y.) was used to deposit the copper layers and monitor the electrode mass. The sensitivity of the crystal was determined during copper deposition using Sauerbrey s equation (Sauerbrey, 1956). The change in mass or frequency was registered with time. 

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