Singular properties of boron-doped diamond/carbon fiber composite as anode in Brilliant Green dye electrochemical degradation

Carbon fiber (CF) and boron doped diamond/carbon fiber (BDD/CF) were applied as anodes for the Brilliant Green dye electrochemical degradation process. CF substrates were obtained from polyacrylonitrile precursor heat treated at 1000 degrees C in a nitrogen atmosphere. BDD films were grown on CF substrates by hot filament chemical vapor deposition with boron source from an additional hydrogen line passing through a bubbler containing B2O3 dissolved in methanol solution with B/C ratio of 15,000 ppm. The electrodes were characterized by field emission gun-scanning electron microscopy images, Raman spectroscopy, and electrochemical impedance spectroscopy showing notable tridimensional characteristics besides their high diamond quality. They were applied to electrochemical degradation of Brilliant Green dye at different current densities using a concentration of 100 mg L-1. Their electrolysis efficiency was analyzed by UV/Vis spectrophotometry technique. The results showed that BDD/CF electrodes were efficient in the solution color removal, regardless of the current density value. BDD/CF electrode under the lowest current density of 10 mA.cm(-2) presented the best performance with higher kinetic constant and color removal percentage associated to its low energetic consumption.