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

A challenging task is to promote Ru atom economy and simultaneously alleviate Ru dissolution during the hydrogen evolution reaction (HER) process. Herein, Ru nanograins (approximate to 1.7 nm in size) uniformly grown on 1T-MoS2 lace-decorated Ti3C2Tx MXene sheets (Ru@1T-MoS2-MXene) are successfully synthesized with three types of interfaces (Ru/MoS2, Ru/MXene, and MoS2/MXene). It gives high mass activity of 0.79 mA mu g(Ru)(-1) at an overpotential of 100 mV, which is approximate to 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 MoS2 and MXene can well disperse and stabilize Ru grains, giving larger electrochemical active area. Then, Ru/MoS2 interfaces weakening H* adsorption energy and Ru/MXene interfaces enhancing electrical conductivity, can efficiently improve the activity. Next, MoS2/MXene interfaces can protect MXene sheet edges from oxidation and keep 1T-MoS2 phase stability during the long-term catalytic process. Meanwhile, Ru@1T-MoS2-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.

Automated summary

Researchers have successfully synthesized a Ru@1T-MoS2-MXene composite material in which Ru nanograins are uniformly grown on 1T-MoS2-decorated Ti3C2Tx MXene sheets. The material exhibits high mass activity and a small Ru dissolution rate. Electrochemical tests and DFT calculations reveal the role of triple interface optimization in improving activity and stability.