Active and stable TiSiBDD anodes for electro-oxidation

Boron-doped diamond film grown on a titanium substrate (Ti/BDD) has shown certain stability with superior activity. The causes of its eventual failure may be the large thermal residual stress in the diamond film, which leads to the delamination of the film. A dissociation of TiC layer would collapse the diamond film also. Ti/BDD stability is expected to be improved by coating a thin layer of silicon on the titanium before growing the diamond film at a relatively low temperature. Hot filament chemical vapor deposition was used to grow the diamond film. TiSiBDD electrode has an accelerated lifetime of 320 h, over 20% longer than that of the Ti/BDD. Raman spectroscopy, X-ray diffraction, and scanning electron microscopy examinations demonstrated that the films had well-defined diamond features. TiSiBDD anodes also showed excellent activity in anodic oxidation of typical pollutants like phenol, acetic acid, and maleic acid. A pollutant removal efficiency as high as 90% can be obtained with the effect of pH being insignificant. The current efficiency of slightly over 50% was observed when 90% phenol was degraded in terms of chemical oxygen demand at a current density of 200 A m2. © 2006 The Electrochemical Society. All rights reserved.