TOPOGRAPHICAL IMAGING OF PRUSSIAN BLUE SURFACES BY DIRECT-MODE SCANNING ELECTROCHEMICAL MICROSCOPY

Direct-mode scanning electrochemical microscopy (SECM) was applied to image surface morphology of a Prussian Blue (PB) film. Success in using direct-mode SECM in electrolyte solution was achieved for the first time by controlling the tip and sample electrode potentials with respect to a reference electrode. SECM images with submicron spatial resolution were obtained only when the tip and sample potentials were held at more positive (or negative) and negative (or positive) potentials respectively than the redox potential of PB. The SECM of PB in air was also shown to be possible. Factors governing the spatial resolution of the SECM image are discussed in detail.