Molten salt derived Mo₂AlB₂ with excellent HER catalytic performance

Mo₂AlB₂ is a lamellar transition metal boride that is prepared by selectively etching the MoAlB MAB phase precursor. Most methods for synthesizing Mo₂AlB₂ require the use of strong acids or bases and a long reaction time. In this study, we present a Lewis acid molten salt method for synthesizing the lamellar structured Mo₂AlB₂ by selectively etching a layer of aluminium atoms from the MoAlB precursor. The synthesized Mo₂AlB₂ shows excellent catalytic activity for hydrogen evolution reaction under alkaline conditions, with long-term stability, and a low overpotential of 145 mV and Tafel slope of 76 mV dec⁻¹ at 10 mA cm⁻².