Potentiodynamic behavior of the boron-doped diamond electrodes in Na_2SO_4 with pH 1 to 12

摘要

Diamond thin films, with different concentrations of boron (0 to 20000 ppm B/C) were grown over silicon substrates in a HFCVD furnace. Energy Recoil Detection Analysis (ERDA) measurements revealed both an increase of boron and oxygen atoms in the film with the increase of the dopant concentration. Presence of tungsten carbide in all grown films was detected by syncroton XRD analysis. The potentiodynamic E/I measurements in 1 M Na_2SO_4 with different pH ranging from 1 to 12 revealed that the onset of the OER is shifted to less positive potentials as the solution is made more alkaline. The increase of the concentration of the dopant increased the current related with the reactions associated with the OER. Anodic polarizations decreased the electrode activity while cathodic polarizations could restore the surface activity for both HER and OER.