Heterogeneous NiSe2/Ni Ultrafine Nanoparticles Embedded into an N,S-Codoped Carbon Framework for pH-Universal Hydrogen Evolution Reaction

Developing noble-metal-free electrocatalysts with high efficiency and low cost in the all-pH range is highly desired but challenging. Herein, we constructed the hybrid interface structure of NiSe2 and Ni nanoparticles and embedded them into an N,S-codoped carbon nanosheet framework (NiSe2/Ni-NSC). The partial selenization treatment endows the catalyst with an abundant interface, resulting in optimal electronic structure and hydrogen adsorption energy due to the strong interaction between Ni metal and metallic NiSe2. The ultrafine nanoparticle size allows the active edge sites to be fully exposed and their utilization efficiency to be improved. Benefiting from the structure characteristics, interface engineering, and high electroconductivity, the NiSe2/Ni-NSC exhibits superior and stable hydrogen evolution performances in pH-universal media, especially in acidic solution with an overpotential as low as 53 mV to achieve 10 mA cm–2 current density, compared favorably with most Pt-free catalysts. Our work may pave a novel pathway to design heterostructure catalysts with high performance toward hydrogen evolution in the all-pH range.