Controllable Conversion from Single-Crystal Nanorods to Polycrystalline Nanosheets of NiCoV-LTH for Oxygen Evolution Reaction at Large Current Density

We report the in situ generation of NiCoV-LTH (layered triple hydroxide) on nickel foam (NF) for electrocatalytic oxygen evolution reaction (OER). By adjusting the molar ratio of Co/V, the NiCoV-LTH/NF material can achieve the conversion from single-crystal nanoneedles to polycrystalline nanosheets. Especially, the resultant NiCoV-LTH polycrystalline nanosheets (denoted as P-NiCoV-LTH/NF) only require ultralow overpotentials of 340 and 373 mV to reach the large current density of 500 and 1000 mA cm–2 for OER, respectively, and exhibit ultrastrong durability for over 180 h.