Nickel–Cobalt Modified Boron-Doped Diamond as an Electrode for a Urea/H2O2 Fuel Cell

A nickel–cobalt-modified boron-doped diamond (NiCo-BDD) electrode was prepared by chronoamperometry. A Ni/Co ratio of 4:1 in solution was determined as the optimum ratio for the urea oxidation reaction. Results showed that the Ni and Co particles were homogeneously deposited on the BDD surface and deposited without any interaction between the particles. The prepared NiCo-BDD electrode for a urea fuel cell exhibited optimum performance with a 0.1 M KOH and 0.50 M urea solution as the anode electrolyte and a 2.0 M H2O2 and 2.0 M H2SO4 solution as the cathode electrolyte. An open-circuit voltage of 0.817 V with a power density of approximately 0.632 mW cm−2 at room temperature and excellent stability after 6 h of application were achieved. NiCo-BDD significantly enhanced the catalytic activity of UOR compared with the Ni plate, unmodified BDD, Ni-BDD, and Co-BDD.