Electrochemical behaviour of Ni, Cu, Ag, Pt and glassy carbon electrodes in triethylamine-tris(hydrogen fluoride) medium

Voltammetric responses of Ni, Cu, Ag, Pt and glassy carbon (GC) electrodes in triethylaminetris(hydrogen fluoride) medium in the anodic as well cathod ic potential region were investigated. AAS as well as SEM measurements were also made to ascertain the dissolution rate and surface transformation due to fluoride film formation on the electrode surfaces. On Ni, bulk NiF2 fil m growth occurs only around 4.0 V following a thin NiF2 monolayer formation around 0 V. The NiF2 film shows very little solubility in the medium. Mono layer and bulk CuF2 phases are formed quite close to each other on Cu durin g anodic polarization. The anodically formed CuF2 dissolves to the extent o f 12% in this medium. AgF formation follows a different mechanism during th e first and subsequent anodic sweeps. The effect of MeCN as well as water a ddition on the solubility and stability of these fluoride films are also re ported. Glassy carbon and Pt electrodes are relatively inert in this medium . Anodic voltammetric responses for other reactive species could be observe d only on Pt and GC electrodes. On the cathodic side, all the electrodes sh ow inert behaviour. Electrochemical reduction of PhNO2, for example, could be observed on all the electrodes.