Interfacial Mo-N-C Bond Endowed Hydrogen Evolution Reaction on MoSe₂@N-Doped Carbon Hollow Nanoflowers

Molybdenum diselenide (MoSe₂) has been considered as promising electrocatalysts for catalyzing the hydrogen evolution reaction (HER) due to its narrow band gap and appropriate adsorption free energy. However, its catalytic performance is still impeded by inferior electrical conductivity and insufficient active sites, thus leading to unsatisfactory HER performance. Herein, MoSe₂@N-doped carbon (NC) hollow nanoflowers with interfacial Mo-N-C bonds were controllably fabricated through the in situ selenization of the self-polymerized Mo-polydopamine precursor. Benefiting from the unique hollow structure, NC protective layer, and intimate interfacial interaction, the optimal MoSe₂@NC displays good HER performance with low overpotentials (175 and 183 mV) and long-term stability (up to 12 h at -10 mA cm^-2) in 0.5 M H₂SO₄ and 1.0 M KOH solutions, respectively. The theoretical results show that Mo-N-C bonds at the interface of MoSe₂@NC give rise to relatively low unoccupied e_g orbital density of states and ideal H₂ adsorption free energy. This work presented here highlights the critical role of interfacial chemical bonds in regulating the electronic structure of nanomaterials and further improving the HER performance.