Ultrafine Ru nanoparticles derived from few-layered Ti₃C₂T_x MXene templated MOF for highly efficient alkaline hydrogen evolution

It is meaningful to search high-efficient and inexpensive electrocatalysts for hydrogen evolution reaction (HER) due to the energy crisis and environmental pollution. Here, we report the preparation of ultrafine Ru nanoparticles from a hybrid of ZIF-L(Co) MOF and polydopamine coated few-layered Ti₃C₂T_x MXene (FL-Ti₃C₂T_x). FL-Ti₃C₂T_x is used as a template to grow regular leaf-shaped ZIF-L(Co) nanosheets through the reaction of Co ions anchored on the MXene surface with 2-methylimidazole. The obtained hybrid is then doped with Ru ions through ion exchange between Ru and Co ions, followed by thermal annealing at a temperature of 350 °C in an Ar atmosphere to produce ultrafine Ru nanoparticles. The obtained Ru@ZIF-L(Co)/FL-Ti₃C₂T_x nanocomposite shows outstanding HER performance with a low overpotential of 16.2 mV at a current density of 10 mA cm⁻², a small Tafel slope of 21.0 mV dec⁻¹ and excellent stability in 1.0 M KOH solution. This work provides a new strategy for the design and synthesis of highly efficient HER catalyst via MOFs with tunable composition and structure.