Exploring low-cost and highly efficient Water splitting electrocatalyst has been recognized as one of the most challenging and promising ways. NiCo2S4 core-shell nanorods supported on nickel foam (NF) have been fabricated by a facile hydrothermal method. The electrochemical performance of NiCo2S4@NiCo2S4 for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is studied. NiCo2S4@NiCo2S4/NF exhibits a significantly improved OER and HER performance with an overpotential of 200 mV at 40 mA/cm(2) and an overpotential of 190 mV at 10 mA/cm(2). The combination of low charge-transfer resistance, enhanced interaction and charge transport as well as large electrochemical double-layer capacitance enables superior OER and HER. The NiCo2S4@NiCo2S4/NF nanorod electrode shows excellent electrocatalytic activity with a low voltage 1.57 V and stability with long hour electrolysis, which is highly satisfactory for a prospective bifunctional electrocatalyst. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.