Ultramicroelectrodes fabrication guidelines for multifunctional scanning electrochemical microscopy

Abstract

We report a scalable and versatile protocol for fabricating high-performance metal disk ultramicroelectrodes (UMEs) with precisely controlled geometry for scanning electrochemical microscopy (SECM). By integrating bee-tail shaped nanopipette template with tip forging, our approach achieved precise control over probe morphology, yielding UMEs with RG values as low as ~1.0 and interelectrode gaps of 5-10 μm for dual-barrel configurations. This reproducible method boasts a success rate of >95% across large batches. We demonstrate the practical utility of these probes through simultaneous O2 and pH monitoring during water oxidation catalysis and in situ mapping of lithium ions flux during lithium plating. Our findings establish a reliable platform for the production of sensitive, multifunctional SECM probes, significantly advancing the quantitative investigation of complex interfacial chemical processes in electrocatalysis and energy storage.