What are the requirements for a working electrode material, and which material should I choose?
A working electrode acts as a source or sink of electrons for exchange with molecules in the interfacial region (the solution adjacent to the electrode surface), and must be an electronic conductor. It must also be electrochemically inert (i.e., does not generate a current in response to an applied potential) over a wide potential range (the potential window). Commonly used working electrode materials for cyclic voltammetry include platinum, gold, mercury, and glassy carbon. Other materials (e.g., semiconductors and other metals) are also used, for more specific applications. The choice of material depends upon the potential window required (e.g., mercury can only be used for negative potentials, due to oxidation of mercury at more positive potentials), as well as the rate of electron transfer (slow electron transfer kinetics can affect the reversibility of redox behavior of the system under study). The rate of electron transfer can vary considerably from one material to another, even
