Re₃P₄/ReS₂ Heterostructure With Bidirectional Electron Flow via Ohmic Contact for Enhanced pH-Universal Hydrogen Evolution

The development of transition metal dichalcogenide-based electrocatalysts with outstanding hydrogen evolution reaction (HER) performance and long-term durability across the entire pH range is crucial for achieving energy- and cost-efficient green hydrogen production via water electrolysis. Herein, we demonstrate a unique Re₃P₄/ReS₂ Ohmic contact heterostructure fabricated via a facile hydrothermal process followed by phosphorization, which delivers remarkably efficient and durable HER performance, exhibiting pH-universal activity with low overpotentials of 40 mV (0.5 m H₂SO₄), 66 mV (1.0 m KOH), and 94 mV (1.0 m phosphate buffer solution) at 10 mA cm⁻², together with outstanding stability for 90 h under different current densities at 10, 50 and 100 mA cm⁻². Experimental analysis and theoretical calculations indicate that the Ohmic contact interface can induce interfacial charge redistribution, which optimizes the adsorption energy of reaction intermediates in the HER process. Consequently, the anion exchange membrane water electrolyzer (AEMWE) assembled with Re₃P₄/ReS₂ achieves a low cell voltage of 2.01 V at 1.0 A cm⁻² and maintains stable operation for 500 h at an industrial current density of 500 mA cm⁻². This work provides valuable insight into designing Ohmic contact heterostructures as pH-universal electrocatalysts, advancing the development of efficient hydrogen production technologies under diverse electrolyte conditions.