Scanning Electrochemical Cell Microscopy

FIGURE 17.38 (a) Schematic (not to scale) of the theta pipette system that serves as a localized conductivity 

In variations of the technique, dc can be measured between one of the channels of the capillary and the substrate itself thus providing information on the local conductance properties of the 

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Scanning electrochemical cell microscopy (SECCM) is a recent innovation [161, 167] in electrochemical scanning probe microscopy [168] that has been proven particularly powerful for visualizing electroactivity. In the case of HOPG, the SECCM response also informs on the location of the measurement, that is, basal... 

Snowden, M.E., Giiell, A.G., Lai, S.C.S. et al. (2012) Scanning electrochemical cell microscopy theory and experiment for quantitative high resolution spatially-resolved voltammetry and simultaneous ion-conductance measurements. Analytical Chemistry, 84, 2483-2491. 

Scanning electrochemical cell microscopy (SECCM) uses a capillary with double compartment (dual barrel capillary) pulled to a sharp opening (Fig. 13b) as scanning probe [36]. Both compartments of the capillary are filled with the electrolyte solution, and a quasi-reference counter electrode (QRCE) is inserted in each compartment (Fig. 13a). 

Fig. 13 a Scanning Electrochemical Cell Microscopy (SECCM). b SEM image of the tip of a double barrel capillary. Reproduced from [37] with the permission of Wiley... 

Scanning electrochemical cell microscopy (SECCM) also allows acquisition of high-resolution images of the reactivity of an electrode surface. 

Ebejer, N. Schnippering, M. Colburn, A. W. Edwards, M. A. Unwin, P R., Localized high resolution electrochemistry and multifunctional imaging Scanning electrochemical cell microscopy. Analytical Chemistry 2010, 82, 9141-9145. 

Patten, H. V. Lai, S. C. Macpherson, J. V. Unwin, P. R., Active sites for outer-sphere, inner-sphere, and complex multistage electrochemical reactions at polycrystalline boron-doped diamond electrodes (pBDD) revealed with scanning electrochemical cell microscopy (SECCM). Analytical Chemistry 2012, 84, 5427-5432. 

Ebejer, N. Giiell, A. G. Lai, S. C. McKelvey, K. Snowden, M. E. Unwin, P. R., Scanning electrochemical cell microscopy A versatile techniqne for nanoscale electrochemistry and functional imaging. Annual Review of Analytical Chemistry 2013,6,329-351. 

Recently, by replacing the SECM tip with a microcapillary tip, Dr. Zhan and coworkers at Xiamen University developed a scanning electrochemical cell microscopy (SECCM) as a nanofabrication method (see in Fig. 20). ... 

Last, it is important to note that researchers will (and have already done so) dispute the extensive literature reported above. As such it has been reported that under certain (limited) conditions the basal plane sites have measurable electrochemical activity [25-27]. Using elaborate Scanning Electrochemical Cell Microscopy (SECM) it has been reported that the basal plane sites of freshly exposed HOPG display considerable electroactivity which, interestingly, is time dependant, in that exposure to air for less than one hour after cleaving leads to a decrease in the observed electron transfer rates at the basal surface [27]. Such work is highly fascinating and studies into this time-dependent surface effect are, at the... 

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