Pt modulation of NbSe 2 for enhanced activity and stability: a new Pt 3 Nb 2 Se 8 compound for highly-efficient alkaline hydrogen evolution.

Transition metal dichalcogenides (TMDs) have attracted great attention as electrocatalysts for the hydrogen evolution reaction (HER) due to their tunable crystal structures and active sites. However, compared with group VI TMDs (such as MoS 2 and WS 2 ), the group V TMDs exhibit poor intrinsic catalytic activity towards the HER because the outermost d orbitals of group V metals have only one electron. Herein, we design a new compound Pt 3 Nb 2 Se 8 by Pt modulation of NbSe 2 with enhanced catalytic activity and structural stability for robust HER in an alkaline medium. The introduction of Pt atoms can not only be used as efficient active sites, but also to transfer electrons to Se to synthetically boost the catalytic activity. The Pt 3 Nb 2 Se 8 exhibits an overpotential of 44 mV at 10 mA cm -2 and a Tafel slope of 38.4 mV dec -1 , superior to those of intrinsic NbSe 2 and PtSe 2 , and even exceeding those of commercial Pt/C. This work aims to provide an approach to design group V-based TMDs with enhanced catalytic activity and stability by electronic regulation, as highly efficient electrocatalysts for the HER.