Nano-cubic structured titanium nitride particle films as cathodes for the effective electrocatalytic debromination of BDE-47.

An energetic TiN cathode was fabricated for effective electrocatalytic debromination of 2,2',4,4'-tetrabromodiphenyl ethers (BDE-47); this was achieved by placing Ti foils in an aqueous suspension of TiN nanoparticles, then drying the system at 50 °C for 12 h. TEM and SEM characterization showed that the TiN nanoparticles-whose average size was approximately 50 nm-were ideal nano-cubic structures and distributed uniformly on the Ti substrate. When applied as a cathode in cyclic voltammetry measurements, the TiN electrode exhibited stable electrochemical performance over 20 cycles, in the ∼1-10 pH range. The overpotential of the TiN cathode for electrochemical reduction of water (the main side reaction during the electrocatalytic reduction of pollutants in aqueous solution) was determined as 0.54 V, which was much higher than the values for either a Pt wafer (0.12 V), or a Pt film (0.07 V). The TiN electrodes displayed superior electrocatalytic activity for the electrocatalytic debromination of BDE-47. The kinetic constant of BDE-47 degradation on TiN cathode is 0.65 h(-1), which was 2, 4 and 17 times as much as those on Pt film, Pt wafer and graphite cathodes, respectively. A pathway was proposed for the degradation of BDE-47, based on measurements of the intermediate products resulting from the removal of BDE-47 by GC-MS.