Dual‐Functional N Dopants in Edges and Basal Plane of MoS₂ Nanosheets Toward Efficient and Durable Hydrogen Evolution

Abstract

Herein, the authors explicitly reveal the dual‐functions of N dopants in molybdenum disulfide (MoS 2 ) catalyst through a combined experimental and first‐principles approach. The authors achieve an economical, ecofriendly, and most efficient MoS 2 ‐based hydrogen evolution reaction (HER) catalyst of N‐doped MoS 2 nanosheets, exhibiting an onset overpotential of 35 mV, an overpotential of 121 mV at 100 mA cm −2 and a Tafel slope of 41 mV dec −1 . The dual‐functions of N dopants are (1) activating the HER catalytic activity of MoS 2 S‐edge and (2) enhancing the conductivity of MoS 2 basal plane to promote rapid charge transfer. Comprehensive electrochemical measurements prove that both the amount of active HER sites and the conductivity of N‐doped MoS 2 increase as a result of doping N. Systematic first‐principles calculations identify the active HER sites in N‐doped MoS 2 edges and also illustrate the conducting charges spreading over N‐doped basal plane induced by strong Mo 3 d –S 2 p –N 2 p hybridizations at Fermi level. The experimental and theoretical research on the efficient HER catalysis of N‐doped MoS 2 nanosheets possesses great potential for future sustainable hydrogen production via water electrolysis and will stimulate further development on nonmetal‐doped MoS 2 systems to bring about novel high‐performance HER catalysts.