Enhancement Effect of Borate Doping on the Oxygen Evolution Activity of α-Nickel Hydroxide

The availability of low-cost oxygen evolution catalysts is critical to the successful commercialization of renewable energy conversion and storage systems based on solar energy and water splitting reactions. We demonstrate here that a moderate amount (similar to 12 wt %) of borate doping of crystalline alpha-Ni(OH)(2), a common low-cost catalyst, can lower the Tafel slope of the oxygen evolution reaction (OER) in 0.1 M KOH aqueous solution from the typical value of 60 to 43 mV decade(-1) and the overpotential for 10 mA cm(-2) of current density from 390 to 340 mV. Borate doping also improves the stability of alpha-Ni(OH)(2) in OER The borate-doped alpha-Ni(OH)(2) can even surpass the benchmark Ir/C precious metal catalyst in terms of activity and stability. These results demonstrate the potential of borate doping as a strategy to increase the catalytic activity of base metal water oxidation catalysts.