Confined synthesis of edge-rich V-doped MoSe2 nanosheets on carbon black for advanced hydrogen evolution reaction.

MoSe₂ as one graphene-like 2D transition metal selenide has attracted great attention. However, its application for the hydrogen evolution reaction (HER) is still restricted by the poor electrical conductivity and structural restacking. In this work, an excellent electrocatalyst for hydrogen production is developed based on the in situ synthesis of V-doped MoSe₂ confined on carbon black nanoparticles (denoted as V-MoSe₂/CB) via a sol–gel process. The characterization results show that the carbon black nanoparticles can protect the V-MoSe₂ nanosheets from agglomeration, resulting in ultra-thin thickness and short vertical lattice arrays. Meanwhile, density functional theory (DFT) calculations indicate that vanadium doping can optimize the electronic structure of MoSe₂. Accordingly, compared to the pure MoSe₂, V-MoSe₂ and MoSe₂/CB electrocatalysts, V-MoSe₂/CB exhibits improved electrocatalytic activity with a small overpotential of 166 mV at −10 mA cm⁻² and a small Tafel slope of 65 mV dec⁻¹. This work paves a new way for improving the HER performance through synergistic morphology, structure and electronic regulation. [ABSTRACT FROM AUTHOR]