Preparation of platinum-modified boron-doped diamond for electroreduction of CO₂

Metal-modified boron-doped diamond has been prepared for preliminary study of CO₂ electroreduction. Pt was electrodeposited at boron-doped diamond (BDD) by using chronoamperometry technique. The precursor metal solution concentration of 6 mM was applied with deposition potentials of -0.3 V (vs Ag/AgCl). Characterization by using FESEM and XPS confirmed the presence of Pt on the surface of BDD. Cyclic voltammetry was applied to obtain an optimum condition for electroreduction of CO₂. CO₂ dissolved in 0.1 M NaCl and 0.1 M Na₂SO₄ solutions were applied. A reduction peak, attributable to CO₂, appeared at a potential of -0.7 V (vs Ag/AgCl) in NaCl solution, while no peak was observed in Na₂SO₄ solution. The result indicated that the metal-modified electrodes has successfully prepared as a working electrode for CO₂ electroreduction.