cathodically

Cathodically is an adverb used in electrochemistry and related disciplines to describe a process, reaction, or property occurring at the cathode—the electrode where reduction typically takes place in an electrochemical cell. The term derives from cathode and the suffix -ic, with the adverbial -ly, and is used to distinguish actions at the cathode from those at the anode, where oxidation occurs. In practical contexts, cathodic processes include deposition of material from solution onto a surface, and the reduction of ions or molecules at the cathode.

In electroplating, metal ions are reduced at the workpiece, so the coating forms cathodically. In aqueous electrolysis, hydrogen ions or metal ions may be reduced cathodically to hydrogen gas or a metallic film, respectively. Cathodically oriented conditions are also described in corrosion protection schemes, where a structure is made the site of cathodic reactions to reduce oxidation.

The related adjective cathodic describes properties associated with the cathode, while anodic describes those associated with the anode; cathodically is used when emphasizing the cathodic aspect of a process. The term is mainly encountered in scientific writing and technical discussions of electrochemical reactions, electroplating, battery technology, and related devices.