Ni3S2-embedded NiFe LDH porous nanosheets with abundant heterointerfaces for high-current water electrolysis.

[Display omitted] • Scalable and controllable fabrication of Ni3S2-embedded NiFe LDH porous nanosheets grown on Ni foam in a facile method for OER catalysis. • The Ni3S2-embedded NiFe LDH porous nanosheet integrates merits including abundant interfaces, rapid mass transfer, bubble release and modulated electronic structure. • NiOOH resulting from the in situ partial Ni3S2 phase transformation over an equally important electrically conductive Ni3S2 to drive proficient catalysis. • This OER catalyst only requires an overpotential of 303 mV to deliver 1 A cm-2 toward OER. Ni 3 S 2 -embedded NiFe LDH heterostructured porous nanosheets were in situ grown on nickel foam (Ni 3 S 2 -NiFe LDHs /NF) via a one-pot solution method mediated by NaHS at room temperature in 15 min. Benefiting from the abundant Ni 3 S 2 -NiFe LDH interfaces, the as-prepared catalyst delivers 50, 500 and 1000 mA cm−2 with an overpotential of only 230, 285 and 303 mV for oxygen evolution reaction, respectively, registering as one of the best performing non-precious metal OER catalysts. In situ and ex situ analysis reveal that the Ni 3 S 2 was in situ partially transformed under an electrooxidation environment into NiOOH over an equally important electrically conductive Ni 3 S 2 to drive proficient catalysis. This strategy can be extended to fabricate Ru-Ni 3 S 2 -NiFe LDHs/NF electrocatalyst for high active hydrogen evolution reaction. Coupling these two catalysts achieved remarkable current densities of 10, 100 and 500 mA cm−2 at low voltages of 1.47, 1.71 and 1.85 V upon driving overall water splitting, respectively, superior to the performance of current industrial catalysts (200–400 mA cm−2 at 1.8–2.40 V). [ABSTRACT FROM AUTHOR]