Synergistic effect between sulfur and CoFe alloys embedded in N-doped carbon nanosheets for efficient hydrogen evolution under neutral condition.

[Display omitted] • Sulfur on CoFe alloys embedded in nitrogen-doped carbon nanosheets is designed. • M−S n 2- is the robust catalysis sites for HER. • The synergisms between sulfur and CoFe@NC are beneficial for HER. • 2D NC interacted 3D network supplies easily accessible active sites and rapid charge transfer. • The present S-CoFe@NC exhibits Pt-like HER performance in neutral media. Seeking novel low-cost non-noble metal based electrocatalysts with high efficiency is of great significance to promote industrial application of hydrogen evolution reaction (HER). Herein, we originally demonstrate sulfur on CoFe alloys embedded in nitrogen-doped carbon nanosheets (S-CoFe@NC) catalyst with extremely robust HER activity in neutral media. The present sample exhibits active HER performance with ultralow overpotential of 37 mV at current density of 10 mA cm−2 and Tafel slope of 34 mV dec-1, which is the same as commercial Pt/C. Systemic studies show that strong interaction between bridging S n 2- and CoFe@NC introduces M−S n 2- as the robust catalysis sites for HER, which is also beneficial for the charge exchange. The specific structure of NC nanosheet interconnected network provides structure advantages for easily accessible active sites and fast charge transfer for electrocatalysis. Thus, this work paves a way for the development of new class of sulfur based electrocatalyst with efficient HER performance for neutral water splitting. [ABSTRACT FROM AUTHOR]