Platinum-like oxidation of nickel surfaces by rapidly switching voltage to generate highly active bifunctional catalysts

• A simple procedure to transform a Ni surface into a bifunctional HER Catalyst was developed.
• The resulting surface is characterized electrochemically, and found to be highly active for the HER.
• The increased activity is hypothesized to come from the targeted, novel Ni(OH)x structure.

Recently the importance of catalyzing the water splitting step of the hydrogen evolution reaction (HER) was highlighted. We demonstrate here a treatment to modify a nickel surface into a highly effective bifunctional HER catalyst (i0 = 0.18 A/m2, Tafel Slope = 106 mV/dec) that has a good distribution of both water splitting sites and Hads combination sites. The resulting surface is characterized electrochemically, and with SEM, EDX, XPS and AFM. The data is found to be consistent with the treatment oxidizing the Ni surface in a novel way creating the hypothesized “Ni(OH)x” structure (x between 0 and 2).