In-Situ-Engineered 3D Cu3Se2@CoSe2–NiSe2 Nanostructures for Highly Efficient Electrocatalytic Water Splitting

In-situ engineering of nonprecious catalysts with highly electrocatalytic performances for H2 or O2 generation is one of unresolved challenges in industrial chemistry. In this work, a trimetallic (Cu, Ni, Co) selenide is fabricated in-situ on the nickel–cobalt foam (NCF) modified by the dielectric barrier discharge (DBD) plasma (PNCF) with a facile hydrothermal method. The resulting transition-metal-based selenide (Cu3Se2@CoSe2–NiSe2/PNCF) exhibits excellent catalytic activity for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1 M KOH, and the overpotentials stimulated with a current density of 10 (j10) and 100 (j100) mA cm–2 are ∼42 and 178 mV in HER process, as well as 240 and 270 mV in OER. Specifically, the electrocatalytic activity of Cu3Se2@CoSe2–NiSe2/PNCF is better than the benchmarked RuO2 for OER in the high current density region (>j250). In addition, the amount of H2 and O2 gases for Cu3Se2@CoSe2–NiSe2/PNCF stimulated with j10 are ∼1.52 and 0.9 mmol h–1, respectively, thus exhibiting higher efficiency than numerous nonprecious catalysts containing transition metals.