Nanoarchitectonics of amorphous Fe–Ni–B nanosheets for high throughput overall water splitting reaction.

Amorphous and defect rich Fe–Ni–B alloy nanosheets are developed which can efficiently catalyzes both the hydrogen and oxygen evolution reaction (HER, OER) at low overpotentials, making it an excellent bifunctional catalyst for overall water splitting (OWS) in 1.0 M and 30 wt% KOH electrolytes. The Fe 1.0 Ni 1.0 B||Fe 1.0 Ni 1.0 B electrode couple based electrolyzer can generates an exceptionally high current density of 1100 mA cm−2 and it offers 1.53 V cell voltage against 1.60 V for the crystalline counterpart for OWS at 10 mA cm−2, which are much lower than those of commercial Pt/C||IrO 2. It also demonstrates long cycling stability of 6000 cycles and durability of 70 h, a high exchange current density, mass activity and Faradaic efficiency. The experimental and density functional theory (DFT) studies illustrate the coordination environment of the catalyst and showed corroboratively that modulation of electronic structure due to the amorphous and rich defect nature. [Display omitted] • Amorphous and defect rich Fe–Ni–B alloy nanosheets are successfully developed. • Insights on electrocatalytic overall water splitting reaction with low cell voltage. • Fe 1.0 Ni 1.0 B.||Fe 1.0 Ni 1.0 B electrode couple based electrolyzer offers 1.53 V cell voltage • High current density of 1100 mA cm−2, 60 h stability and high Faradaic efficiency. • Computational and experimental studies corroborate proposed mechanisms. [ABSTRACT FROM AUTHOR]