Sb-doped BiTeI/graphene composite as an efficient electrocatalyst for the hydrogen evolution reaction

Abstract

Two-dimensional bismuth tellurohalide attracted significant attention in hydrogen evolution reaction applications due to the bismuth atom-induced strong spin–orbit coupling, which provides additional pathways for electron transitions. In this study, Sb-doped BiTeI/graphene composites were successfully synthesized through a combination of chemical vapor transport and mechanical stirring. The obtained materials demonstrated excellent electrocatalytic hydrogen evolution performance under acidic conditions, achieving an overpotential of 188 mV at a current density of 10 mA cm⁻² and a Tafel slope of 53 mV dec⁻¹ in 0.5 M H₂SO₄. Even at a high current density of 100 mA cm⁻², the overpotential remained as low as 272 mV, indicating both high activity and stability. The effective modulation of the intrinsic electronic structure of BiTeI by Sb-doping and fast charge transfer at the composite interface results in improved performance. This study not only provides an efficient hydrogen evolution reaction catalyst but also proposes a generalizable design strategy that can be extended to other layered ternary materials.