NiSe2 nanoparticles embedded in carbon nanowires as highly efficient and stable electrocatalyst for hydrogen evolution reaction

Clean hydrogen energy through water splitting via hydrogen evolution reaction (HER) has attracted much interests. It is significant and urgent to search for low-cost non-noble metal electrocatalysts for highly efficient and stable HER. Herein, for the first time, we present a facile and cost-effective hydrothermal and selenization strategy to synthesize NiSe 2 nanoparticles embedded in carbon nanowires (NiSe 2 /C NWs). As a HER electrocatalyst, the NiSe 2 /C NWs hybrid delivers outstanding catalytic performance with a very low Tafel slope of 38.7   mVdec −1 , a small onset potential of ∼−144   mV (vs RHE), and a high cathode current density of 33   mA   cm −2 at −250   mV (vs RHE). Moreover, it also exhibits excellent long-term stability of NiSe 2 /C NWs even after 2000 voltammetric sweeps. The superior HER performance of NiSe 2 /C NWs is attributed to its unique structure constructed by ultrafine NiSe 2 nanoparticles homogenously embedded in highly conductive carbon nanowires, which can not only provide abundant HER active sites, but also enhance the conductivity between the nanoparticles. It suggests that NiSe 2 /C NWs hybrid is a promising candidate to replace noble metal electrocatalysts for HER.