A facile lyophilization synthesis of MoS₂ QDs@graphene as a highly active electrocatalyst for hydrogen evolution reaction

Highlights: • The target catalyst was prepared by a facile and novel lyophilization method. • The HER activity of various morphologies of MoS₂-based catalysts were studied. • The catalyst owns superior dispersion, large active sites and high conductivity. • The catalyst exhibits superior HER activity and long-term stability. - Abstract: The development of robust, active and nonprecious electrocatalysts for hydrogen evolution reaction is quite urgent but still challenging. Here MoS₂ QDs@Graphene is prepared via a facile lyophilization method, which leads to a better dispersion of MoS₂ QDs on the graphene and optimizes the electronic mobility between the MoS₂ layers. Impressively, the electrocatalyst MoS₂ QDs@Graphene demonstrates the remarkable activity for HER in 0.5 M H₂SO₄ solution, with a current density of 10 mA cm⁻² at a low overpotential of 140 mV and strong stability in acid condition. The achieved excellent performance is attributed to its morphology with large amount of active sites fabricated by the lyophilization method. This new method opens new pathway for the fabrication of non-precious metal electrocatalysts achieving high activity.