Integrated Scanning Electrochemical Cell Microscopy Platform with Local Electrochemical Impedance Spectroscopy using Preamplifier

Abstract

Local electrochemical impedance spectroscopy (LEIS) has emerged to characterize local electrochemical processes on heterogeneous surfaces. However, the current LEIS heavily relies on lock-in amplifier that has a poor gain effect for weak current, limiting the achievement of high-spatial imaging. Herein, an integrated scanning electrochemical cell microscopy is developed by directly collecting the alternating current (AC) current signal through a preamplifier. The recorded local current (sub nA-level) is compared with the initial excitation signal to get the parameters for Nyquist plotting. By integrating this method into a scanning electrochemical cell microscopy (SECCM), an image of LEIS at the Indium Tin Oxide/gold (ITO/Au) electrode is obtained with a spatial resolution of 180 nm. The established SECCM platform is integrated that could be positioned into the limited space (e.g. glove box) for real characterization of electrodes.