Highly stable 1T-MoS2 by magneto-hydrothermal synthesis with Ru modification for efficient hydrogen evolution reaction

Abstract

Obtaining highly stable 1T-MoS₂ is very crucial to investigate the hydrogen evolution reaction (HER) due to the thermodynamically metastable characterization of 1T-MoS₂. Currently, the preparation of pure phase and stable 1T-MoS₂ is a big challenge, which limits the investigation of MoS₂ as an electrocatalyst for better HER performance. In this study, highly stable MoS₂ with different 1T content was prepared by magneto-hydrothermal synthesis, showing that the pure 1T-MoS₂ has the best HER performance with an overpotential of 189 mV at the current density of 10 mA cm⁻² amongst the MoS₂ electrocatalysts with different 1T content. Furthermore, magneto-hydrothermal-synthesized highly stable and pure 1T-MoS₂ was modified with Ru nanoparticles to improve the HER activity, delivering very low overpotential of 81 mV at a current density of 10 mA cm⁻², small Tafel slope of 54 mV dec⁻¹ as well as long stability. Theoretical analysis based on density functional theory shows that 1T-MoS₂ has a lower Gibbs free energy change of adsorbed hydrogen (ΔG_H*) (1.26 eV) as compared with that of 2H-MoS₂ (1.96 eV), and 1T-MoS₂ with Ru modification will obviously suppress the ΔG_H* (0.02 eV). This work confirms that 1T-MoS₂ is efficient as an HER catalyst and Ru modification can further improve the electrocatalytic HER activity.