Facile and fast route of electrodepositing chloride ion-modified NiFePt layered double hydroxides for hydrogen evolution reaction

Abstract

NiFe-based layered double hydroxide (LDH) is a promising electrocatalyst for alkaline water electrolysis because of the low cost and earth abundance of Ni and Fe, as well as their characteristic layered structure resulting in high electrocatalytic performance. However, its hydrogen evolution reaction (HER) activity is still insufficient compared to existing catalysts. Additionally, the hydrothermal method, a common LDH fabrication method, can be time-consuming and complicated. Herein, we suggest a facile route for the preparation of HER catalyst within tens of seconds using one-pot electrodeposition with only a few ionic additives. A trace amount of Pt ion was added to enhance the HER performance and chloride (Cl−) ion was used to increase the specific surface area of the catalyst as well as to control the reduction of Pt ion for Pt-O bonding. Consequently, the 2.5 mmol Cl− ion treated NiFePt LDH (NiFePt_Cl LDH) requires an overpotential of only 52 mV to reach a current density of 100 mA cm−2 and significantly improved durability, with an overpotential increase of only 7 mV at 100 mA cm−2 after 1,000 cyclic voltammetry scans.