New electrode materials and devices for thermoelectrochemical studies and applications

Heated electrodes have been introduced a few decades ago to perform thermoelectrochemical investigations in a very flexible manner. This review considers unusual materials and devices that have been introduced recently to create new heated and also actively cooled electrodes: carbon paste with ionic liquids as binder, carbon nanotubes, iridium, Hg films, Bi films, Bi-Au alloys, gold nanostructures, and indium-doped tin oxide. Scanning electrochemical microscopy (SECM) based on thermocouple tips, as well as SECM of heated electrode arrays, and hot-tip-SECM have been proposed to study surfaces. Thermo-responsive layers allow for rapid switching of heated electrode surfaces. Recent years have seen a broad variety of thermoelectrochemical studies enabled by actively heated and cooled electrodes based on new materials. Very quick temperature changes and very high energy efficiency are two very distinct advantages of directly heated electrodes over both isothermal electrochemical cells and indirectly heated electrodes that suffer from high heat capacity.