Ultrafast Electrodeposition of Ni Metal and NiFe Hydroxide Composites with Heterogeneous Nanostructures as High Performance Multifunctional Electrocatalysts

Water electrolysis provides an efficient method to produce hydrogen as clean energy source. Developing high activity electro‐catalysts towards the oxygen evolution reaction (OER) is crucial to improve the energy‐conversion efficiency of water electrolysis. In this work, heterogeneous nanostructures of NiFe hydroxide composites decorated by Ni metal were directly grown on a porous nickel foam (NF) substrate through an ultrafast electrodeposition process at a large cathodic current density of 1.5 A cm−2 within only 2 seconds. The as‐prepared Ni/NiFe (OH)x–1500 electrode offers a low OER overpotential of 240 mV at 10 mA cm−2 and 290 mV at 100 mA cm−2, a small Tafel slope of 36 mV Dec−1, which are superior to those of a commercial RuO2/Ti electrode. Moreover, Ni/NiFe (OH)x–1500 shows good stability and low cell voltage in the long‐time alkaline‐water splitting. Additionally, the Ni/NiFe (OH)x–1500 electrode also displays excellent electro‐catalytic activity toward the oxidation of hydrazine and glucose. This work provides a facile and rapid method to obtain high performance multifunctional electro‐catalysts. Applied electro‐oxidation catalysis: Ni metal modified NiFe hydroxide nanosheets with open‐pore structures are grown in‐situ on Ni foam through an ultrafast electrodeposition process within 2 s at a high cathodic current density of 1.5 A cm−2. The prepared nanosheets exhibit superior catalytic performance toward electro‐oxidation reaction of water, hydrazine and glucose.