A Systematic Study of MXenes for Hydrogen Evolution Reaction

Two-dimensional (2D) transition metal carbides and nitrides (MXenes) are a large family of earth-abundant materials with more than forty compositions synthesized since 2011, such as Ti₂CT<i>_x</i>, Nb₂CT<i>_x</i>, Ti₃C₂T<i>_x</i>, and Mo₂Ti₂C₃T<i>_x</i>_. MXenes have emerged as promising candidates for catalytic energy storage and conversion due to their electrochemically active surfaces combined with hydrophilicity, high electrical conductivity, and affinity to bond to molecules and nanomaterials to form hybrid structures. The ease of production of MXenes and their earth-abundant elements can overcome one of the major obstacles to the large-scale implementation of durable and efficient catalysts. In this talk, we will discuss the control of MXene transition metals and their surfaces to tune their electrocatalytic behavior. Specifically, we present a systematic study of 20 different MXenes, including novel compositions such as W₂TiC₂T<i>_x</i> and Mo₂Nb₂C₃T<i>_x</i> and high-entropy MXenes, and discuss how we achieve low overpotential for hydron evolution reaction (as low as ~160 mV).