Superlattice in a Ru Superstructure for Enhancing Hydrogen Evolution.

Superlattices are attracting extensive attention due to their unique properties. Nevertheless, the observations of superlattices are limited to those layered structures with weak interlayered interactions, and the effect of the superlattice in metal-based nanostructures on catalysis is unexplored yet. We here report a facile wet-chemical method for synthesizing two-dimensional Ru multilayered nanosheets (Ru MNSs) with a superlattice. Characterizations reveal that the superlattice is formed by stacking Ru layers with twisted angles from 2° to 30°. Owing to the strong synergy between the adjacent layers, Ru MNSs can serve as an efficient catalyst for the alkaline hydrogen evolution reaction (HER). Theoretical calculations reveal that the superlattice can induce the strain effect, which leads to lattice contraction and weak *H adsorption ability, as a result of improved HER performance. This work sheds new light on the utilization of the superlattice on enhancing catalysis in metal-based materials.