Electrocatalytic water splitting to produce H-2 and O-2 has been considered as one of the most perfect solutions to resolve energy problems. Herein, we report the in situ deposit method on surface of Co9S8 by adjusting the number of sedimentary cycles to adjust Ni(OH)(2) loading capacity, and then firstly using the materials as water oxidation and water reduction catalysts. The one-dimensional Co9S8 nanorods was acted as an perfect support to enhance the uniform dispersion of amorphous Ni(OH)(2) nanoparticles, and the electrocatalytic deposited amorphous Ni(OH)(2) nanoparticles wrapped in the surface of Co9S8 nanorods highly improve the interfacial effect and afford more effective active centers for water splitting reaction. When Co9S8@Ni(OH)(2)(-) amorphous/NF-2h-2 cycles, Co9S8@Ni(OH)(2) - amorphous/NF-10h-2 cycles and Ni(OH)(2)(-) amorphous/NF is acted as a bifunctional catalyst, Co9S8@Ni(OH)(2)(-) amorphous/NF-2h-2 cycles presents a lower cell voltage (1.55 V@10 mAcm(-2)) than Co9S8@Ni(OH)(2)(-) amorphous/NF-10h-2 cycles (1.57 V@10 mAcm(-2)) and Ni(OH)(2)(-) amorphous/NF (NA412)10 mAcm(-2)). The activity of Co9S8@Ni(OH)(2)(-) amorphous/NF-2h-2 cycles is compared to that of the ideal the benchmark 25 wt % RuO2/NF-30 wt % Pt/NF (1.56 V@10 mAcm(-2)). Density functional theory (DFT) calculations were calculated to expound more mechanism on the interface effect of the sulfide/hydroxide-based catalysts for HER. For the two kinds of composite catalysts, both catalysts show good activity and stability in this work. Experiments show that Ni(OH)(2) does protect Co9S8 from corrosion under alkaline conditions. Our work paves the way for the development of environmentally friendly and relatively non-toxic water splitting electrocatalysts in terms of largescale applications. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.