Interfacial Engineering of MoSe2/WSe2 Heterostructure for Highly Dispersed Ru Nanocluster Catalysts Enabling pH-Universal and Seawater Hydrogen Evolution

Abstract Designing a robust and efficient electrocatalyst for hydrogen evolution reaction (HER) across diverse electrolytes remains a critical challenge for sustainable hydrogen production. Herein, we demonstrate a surface-engineered MoSe2/WSe2 heterostructure as a catalyst support for anchoring ruthenium (Ru) nanoclusters via tunable electrodeposition, enabling superior HER activity in acidic, alkaline, and seawater media. The heterostructure, prepared via sonication-assisted exfoliation and optimized at a MoSe2/WSe2 ratio of 3:1, provides abundant edge sites and favorable electronic modulation for Ru deposition. Advanced characterization (e.g., STEM, XPS, XANES, and EXAFS) confirms uniform Ru anchoring on the heterostructure surface, accompanied by interfacial coupling and charge redistribution from Ru to Mo/W sites. Electrochemical analysis reveals that the optimized Ru60 configuration exhibits outstanding HER activity with low overpotentials of 118 mV (0.5 M H2SO4), 61 mV (1 M KOH), and 286 mV (seawater) at 10 mA cm–2 along with Tafel slopes of 48–92 mV dec–1. Notably, Ru60 delivers a high mass activity of 1860 A g–1 at 100 mV and superior intrinsic activity with turnover frequencies of 1.01 and 6.85 s–1 at 100 and 150 mV, respectively, outperforming Ru/C and commercial Pt/C. Moreover, durability tests demonstrate negligible performance decay after 5000 cycles and stable operation at high current densities of ∼100, ∼70, and ∼25 mA cm–2 for 72 h in acidic, alkaline, and seawater electrolytes, respectively, with a preserved morphology and crystallinity. Therefore, this work demonstrates a scalable strategy for the interfacial engineering of 2D heterostructures with dispersed Ru nanoclusters, offering a promising pathway toward efficient, durable, pH-universal, and seawater electrolyzers for green hydrogen production.