• • Ru/ReS2 heterostructure achieves an overpotential of 47 mV at 10 mA cm−2 in acidic HER, outperforming Pt/C (54 mV) and many reported Ru-based catalysts, indicating superior intrinsic activity.
• • Tafel slope of 38 mV dec−1 for Ru/ReS2 suggests a Volmer-Heyrovsky mechanism with rapid kinetics, crucial for high-current-density operation in industrial electrolyzers.
• • Exceptional durability: after 10,000 CV cycles, Ru/ReS2 shows negligible overpotential increase, whereas Pt/C degrades by ~54 mV, demonstrating long-term operational stability essential for commercial viability.
• • The d-p coupling between Ru and ReS2 optimizes ΔG_H* and water adsorption, as confirmed by DFT, providing a design principle for enhancing HER performance in TMD-based catalysts.