NiFe Layered Double-Hydroxide Nanosheets on a Cactuslike (Ni,Co)Se₂ Support for Water Oxidation

The oxygen evolution reaction (OER) is a pivotal half-reaction for next-generation energy storage and conversion technologies, for example, in metal–air batteries and water splitting. Herein, we report the preparation of a freestanding cactuslike structural (Ni,Co)­Se2 support shelled with NiFe layered double hydroxides (LDHs), as a highly active and durable OER catalyst with low cost. This cactuslike selenide support provides an interconnected conductive and robust framework, which can ensure efficient electron transfer and prevent the aggregation of LDHs. The synergistic combination and coupling effects of active NiFe-LDH and conductive (Ni,Co)­Se2 raise the intrinsic catalytic activity. As expected, when serving as an OER catalyst in 1 M KOH aqueous solution, the (Ni,Co)­Se2/NiFe-LDH presents a high activity with overpotential of ≈205 mV at a current density of 10 mV cm–2, a small Tafel slope of ≈61 mV dec–1, as well as a high durability observed at 30 h of a chronoamperometric test. The present study shows the promise of the cactuslike structural (Ni,Co)­Se2/NiFe-LDH as an effective OER catalyst, which provides a new thought for the fabrication of non-noble-metal catalysts and desired nanostructures