HO assisted hydrogen spillover over Ru-MoTiC for efficient alkaline hydrogen evolution.

The limited supply capacity and high transport kinetic energy barrier of H* hinder the implementation of the alkaline hydrogen evolution reaction (HER). Constructing an HO environment can effectively enhance the concentration and diffusion kinetics of H*, thereby alleviating the associated limiting factors. Here we report a novel Ru nanoclusters supported by 2D MoTiC nanosheets (Ru-MoTiC) as an effective HER electrocatalyst in alkaline environments. Results indicate that H* is rapidly generated at the Ru site due to the efficient water dissociation capability of Ru-MoTiC, subsequently combining with water molecules to form HO. HO then rapidly diffuses to the -O group on MXene, which can release H* and act as active sites for H evolution, facilitated by the lower migration energy barrier of HO. This strategy simultaneously enhances both the supply and transfer of H*, facilitating synergistic catalysis between Ru and MXene. Consequently, Ru-MoTiC exhibits an overpotential of 47 mV at 10 mA cm, lower than that observed in acidic media (108 mV). This paper introduces a new approach for the development of catalytic materials aimed at achieving efficient and pH-universal electrochemical H evolution.