Surface galvanostatic hydrogen deposition

The cell employed for the electrolytic production of NF3 was a cylindrical nickel cell of 1.5 dm in volume. A BDD with boron concentrations of 2500, 5000, 7500, 8000,10 000, and 12 500 ppm was used as the anode for the electrolytic production of NF3. For galvanostatic measurement of the anode polarization curve, a carbon anode (FE-5 Toyo Tanso Co., Ltd.) was also used in addition to the BDD anode. The BDD thin film (Permelec Electrode Ltd.) was prepared by the hot filament chemical vapor deposition (HFCVD) method on a carbon substrate using a gas mixture composed of CH4-H2-B(CH30)3-Ar. The anode was located at the center of the cell and the cell wall was utilized as the cathode. A nickel rod of 0.1 cm surface area pre-treated with anodic oxidation in a dehydrated NH4F-2HF melt was used as the reference electrode. The nickel rod functions as NiF Oy/Ni (0.073 V versus RHE) [4]. A PTFE skirt was provided between the anode and the cathode compartments, and the anode gas was separated from hydrogen evolved at the cathode to prevent an explosion. The cell bottom was covered with a PTFE sheet to avoid hydrogen evolution. 

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