Enhanced hydrogen evolution catalysis from osmotically swollen ammoniated MoS2

Abstract

An osmotically swollen ammoniated MoS₂ electrocatalyst for hydrogen evolution is developed via a simple hydrothermal route for the first time. The applied relatively high temperature and pressure promote the diffusion of NH₄⁺ ions into MoS₂ lamellar structures, leading to the formation of ammoniated MoS₂ with remarkable lattice expansion. The insertion of NH₄⁺ ions induces a great enhancement in the electrical conductivity of MoS₂, resulting in an excellent activity for the hydrogen evolution reaction with a small Tafel slope of 45 mV dec⁻¹, which is amongst the best recorded for MoS₂-based catalysts, making it a very promising electrocatalyst to replace Pt-based ones.