Rhenium anchored Ti₃C₂T_x (MXene) nanosheets for electrocatalytic hydrogen production

Atomically thin Ti₃C₂T_x (MXene) nanosheets with rich termination groups, acting as active sites for effective functionalization, are used as an efficient solid support to host rhenium (Re) nanoparticles for the electrocatalytic hydrogen evolution reaction (HER). The newly designed electrocatalyst - Re nanoparticles anchored on Ti₃C₂T_x MXene nanosheets (Re@Ti₃C₂T_x) - exhibited promising catalytic activity with a low overpotential of 298 mV to achieve a current density of 10 mV cm⁻², while displaying excellent stability. In comparison, the pristine Ti₃C₂T_x MXene requires higher overpotential of 584 mV to obtain the same current density. After being stored under ambient conditions for 30 days, Re@Ti₃C₂T_x retained 100% of its initial catalytic activity for the HER, while the pristine Ti₃C₂T_x retained only 74.8% of its initial value. According to our theoretical calculations using density functional theory, dual Re anchored MXene (Re@Ti₃C₂T_x) exhibits a near-zero value of Gibbs free energy (ΔG_H* = −0.06 eV) for the HER, demonstrating that the presence of Re significantly enhances the electrocatalytic activity of MXene nanosheets. This work introduces a facile strategy to develop an effective electrocatalyst for electrocatalytic hydrogen production.