Enhanced electrochemical oxidation of organic pollutants by boron-doped diamond based on porous titanium

• The structure of porous Ti enhanced the surface area of BDD film electrode.
• 3D-Ti/BDD electrode exhibited higher response current for organic pollutants.
• Higher generation ability and rate of OH could be obtained on 3D-Ti/BDD electrode.
• Current efficiency was improved by the introduction of porous Ti.
• The discrepancy between promotion of COD removal and enhancement of OH was discussed.

The main aim of the present study was to explore the potential of boron-doped diamond (BDD) film electrode on porous titanium (Ti) substrate to promote the electrochemical oxidation of organic pollutants. Porous Ti endowed the Ti/BDD film three-dimensional porous structure. The electrochemical effective surface area for porous Ti/BDD anode was 8.37 cm2/cm2, 3.2 times as much as that of two-dimensional flat Ti/BDD electrode. Furthermore, the generation ability and rate of hydroxyl radical (OH) on porous BDD electrode were enhanced due to the porous structure of BDD film. The step currents on porous Ti/BDD were about 2 times of those on flat Ti/BDD electrode from chronoamperometry curves, porous Ti/BDD exhibited superior indirect electrochemical oxidation ability. The results of electrodegradation of several typical organic pollutants (oxalic acid, phenol, sodium dodecylbenzene sulfonate, xylenol orange) revealed that current efficiencies on porous Ti/BDD electrode were about 30% higher compared with flat BDD electrode, corroborating the enhanced of electrochemical oxidation as the introduction of porous Ti substrate. Moreover, the discrepancy between promotion of COD removal rate and enhancement of OH was discussed.

Porous Ti endowed the Ti/BDD film three-dimensional porous structure and porous Ti/BDD film electrode exhibited superior indirect electrochemical oxidation ability for organic pollutants. Higher current efficiency could be realized on porous Ti/BDD electrode for electrochemical oxidation of pollutants.Figure optionsDownload as PowerPoint slide