Multilayered Ti₃C₂T_x MXene as a highly active electrocatalyst for hydrogen evolution reaction

Two dimensional materials as electrocatalysts for hydrogen evolution reaction (HER) have recently gained significant interest. Here, we report the HER activity of multilayered MXene ( $\text{ML}-{\text{Ti}}_3{C}_2{T}_x$ ) synthesized via hydrogen fluoride etching of the ${\text{Ti}}_3{\text{AlC}}_2$ MAX phase. The layered morphology and the presence of both -O, -F based surface termination groups of the $\text{ML}-{\text{Ti}}_3{C}_2{T}_x$ MXene resulted in a better HER activity with a low overpotential of 147 mV at a current density of 10 mA cm^-2 with a steeper Tafel slope of 80 mV dec^-1. Interestingly, $\text{ML}-{\text{Ti}}_3{C}_2{T}_x$ showed a two-fold increase in the HER activity under continuous operation (50 hr, 5,000 cycles) when compared with Pt/C, suggesting good stability and durability in hydrogen production at a high rate in an acidic medium.