Superlattices in Ru Metallene Nanobelts for Robust Hydrogen Evolution

Abstract

2D materials, especially 2D superlattices with tailored geometries, represent an emerging class of promising electrocatalysts for sustainable energy conversion. However, the development of 2D superlattices has been largely confined to self-assembled layered structures, and it remains a great challenge to rationally design the distances between neighboring metal sites at the atomic level to match the adsorption configurations of key species in the target reaction pathways. In this work, a general strategy is reported for synthesizing Ru metallene nanobelts (Ru-ene) in-plane superlattices using molten salts as space-confined growth templates. The fabricated Ru-ene superlattices consist of Ru atom pairs separated by atomic-level distance periodicity of 0.32 nm and a high density of active sites. Both experiments and DFT calculations show that the Ru-ene superlattices structure enhances the adsorption of H₂O and accelerates the desorption of H*. The Ru-ene superlattices exhibits excellent hydrogen evolution reaction (HER) performance with a small overpotential (η₁₀ = 50 mV), a low Tafel slope (42.38 mV dec⁻¹), as well as good long-term stability. This work not only provides a new method for constructing in-plane superlattices materials, but also establishes an intrinsic mechanistic correlation between the atomic distance, ΔG_H* of H-adsorption, and the HER performance.