Structural and electrochemical characterisation of metal doped diamondlike carbon films

The structural and electrochemical characteristics of metal doped diamondlike carbon films with conductivities higher that 5 Ω^-1 cm^-1 are investigated using TEM and electrochemical characterisation techniques. Cyclic voltammetry of hafnium doped diamondlike carbon films in acidic solutions shows that these films are electrochemically stable compared with pure hafnium metal surfaces. Highly doped Cr–DLC films show the presence of metal dopant in the form of nanoclusters while moderately doped films show randomly dispersed chromium metal dopant. In addition, these Cr–DLC films with nanoclusters of metal dopant show two orders of magnitude enhancement in electrochemical activity with gas evolution in acidic environments compared with the Cr–DLC films with randomly dispersed metal dopant. This difference is attributed to possible electrocatalytic activity of nanoclusters.