DESIGN AND PERFORMANCE OF A MINIELECTROCHEMICAL CELL FOR SPATIAL-RESOLUTION OF 2-DIMENSIONAL STRUCTURES

Electrochemical measurements on 2-dimensional layered materials, such as metal dichalcogenides and highly ordered pyrolytic graphite, often require isolation of the crystal edges or defects. Masking the crystal with epoxy may be undesirable since this prevents recleaving the electrode to expose a fresh surface. A minielectrochemical cell is presented that allows experiments to be performed in a single drop (1-3 mm diameter) of electrolyte held against the working electrode. The electrochemical behavior and operational considerations of the cell for an aqueous and nonaqueous system are compared. While the aqueous system generally maintains semiinfinite linear diffusion, the drop geometry in the nonaqueous system induces thin-layer effects. Although some applications may not be possible, utilization of the cell for semiconductor electrochemistry is established. Spatially resolved electrochemistry is demonstrated for n-WSe2 and highly ordered pyrolytic graphite.