Mild formation of Ni(OH)2 dense nanosheets array for ultra-efficient electrocatalytic hydrogen evolution.

Synthesizing high performance and affordable nickel-based electrocatalysts has been one of the research hotspots in the field of clean energy conversion. Herein, facile electroless plating accompanied with mild impregnation method is explored to synthesize petal-like Ni(OH) 2 flakes on carbon cloth (CC) for electrocatalytic alkaline hydrogen evolution reaction (HER). Notably, the optimal Ni(OH) 2 /CC electrode has outstanding HER activity requiring only 24.6 mV vs. RHE of overpotential to reach 25 mA cm−2 of current density, and only 101.5 mV vs. RHE of overpotential to reach 100 mA cm−2. Meanwhile, the 25-h stability test results performed well. This is primarily due to its plentiful interfacial contact, favorable surface morphology of ultrathin and dense nanosheets array, and rapid electron transport. Overall, this study provides a viable approach for the development of efficient, low-cost, hydrophilic nickel-based catalysts for electrocatalytic water splitting applications. [Display omitted] • Ni(OH) 2 /CC electrode is prepared by electroless plating coupled with impregnation. • Hydrophilic dense nanosheets array of Ni(OH) 2 is obtained under mild conditions. • Ni(OH) 2 /CC requires only 24.6 mV vs. RHE overpotential to reach 25 mA cm−2. • Ni(OH) 2 /CC requires only 101.5 mV vs. RHE overpotential to reach 100 mA cm−2. [ABSTRACT FROM AUTHOR]