Co 9 S 8 nanowires@NiCo LDH nanosheets arrays on nickel foams towards efficient overall water splitting.

Water electrolysis is considered to be an effective way to fabricate hydrogen, and it is desirable to find the highly efficient, inexpensive and good durability bifunctional electrocatalysts for overall water splitting. In this paper, we synthesis a unique structured catalyst that was composed by Co ₉ S ₈ nanowires and nickel cobalt layered double hydroxide (NiCo-LDH) nanosheets. The ultrathin nanosheets decorated on the Co ₉ S ₈ nanoarrays offer large specific surface area, numerous active edge sites and excellent electrical conductivity for fast electron transfer. Benefiting from this heterogeneous structure, the catalyst presents excellent catalytic performance in alkaline media. It requires 168 mV to reach current density of 10 mA/cm ² for HER and 278 mV to reach current density of 30 mA/cm ² for OER. When used as electrode in a homemade two-electrode system, it only needs t a voltage of 1.63 V to achieve current densities of 10 mA/cm ² , which proves Co ₉ S ₈ @NiCo LDH/NF as a superior bifunctional catalyst for water splitting.
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