Engineering ordered dendrite-like nickel selenide as electrocatalyst

Surface modification of nanostructured catalysts is fundamental in accelerating sluggish oxygen evolution reaction (OER). Herein we demonstrate that nanostructured Nickel Selenide (NiSe2) exhibits excellent capability for OER owing to the high compatibility between (200) plane and alkaline solution. The dendrite-like nickel selenide achieves a specific current density of 10 mA/cm 2 at an overpotential low to ∼299 mV. The NiSe2 has high stability, in which overpotential decreased ∼2 mV after 10 000 cycles. We demonstrated that the catalytic efficiency of OER could be promoted by increasing the exposure ratio of (200) plane. This work discloses that kinetics of OER are related to specific facets exposure, in which it opens up the possibility of designing active and stable catalysts for OER utilization.