A gas-diffusion gold-ring-tip: Fabrication, characterization, and application in electrocatalysis

A gas-diffusion gold-ring microelectrode used as scanning electrochemical microscopy tip was fabricated. Compared to the ring-tip for droplet dispensation reported before, the as-fabricated micropipette tip has a larger ring size (ca. 25 μm diameter) that is beneficial to gas dispensation and is more sensitive to electroactive species. This micropipette electrode functioned as both a normal SECM tip and a gas dispenser was demonstrated by imaging FcMeOH+/FcMeOH reaction and electrocatalytic oxygen reduction reaction, respectively.