Triple Interface Optimization of Ru‐based Electrocatalyst with Enhanced Activity and Stability for Hydrogen Evolution Reaction

Abstract A challenging task is to promote Ru atom economy and simultaneously alleviate Ru dissolution during the hydrogen evolution reaction (HER) process. Herein, Ru nanograins (≈1.7 nm in size) uniformly grown on 1 T ‐MoS 2 lace‐decorated Ti 3 C 2 T x MXene sheets (Ru@1 T ‐MoS 2 ‐MXene) are successfully synthesized with three types of interfaces (Ru/MoS 2 , Ru/MXene, and MoS 2 /MXene). It gives high mass activity of 0.79 mA µg Ru −1 at an overpotential of 100 mV, which is ≈36 times that of Ru NPs. It also has a much smaller Ru dissolution rate (9 ng h −1 ), accounting for 22% of the rate for Ru NPs. Electrochemical tests, scanning electrochemical microscopy measurements combined with DFT calculations disclose the role of triple interface optimization in improved activity and stability. First, 2D MoS 2 and MXene can well disperse and stabilize Ru grains, giving larger electrochemical active area. Then, Ru/MoS 2 interfaces weakening H * adsorption energy and Ru/MXene interfaces enhancing electrical conductivity, can efficiently improve the activity. Next, MoS 2 /MXene interfaces can protect MXene sheet edges from oxidation and keep 1 T ‐MoS 2 phase stability during the long‐term catalytic process. Meanwhile, Ru@1 T ‐MoS 2 ‐MXene also displays superior activity and stability in neutral and alkaline media. This work provides a multiple‐interface optimization route to develop high‐efficiency and durable pH‐universal Ru‐based HER electrocatalysts.