Constructing Cu2S/amorphous/Cu–Ni–Mo heterostructure for enhanced HER in neutral chloride media via atomic-scale interfacial engineering

Electrolysis of neutral saline wastewater/seawater enables sustainable hydrogen production but faces sluggish hydrogen evolution reaction (HER) kinetics and poor durability in chloride-rich media. Herein, a novel Cu 2 S/Amorphous/Cu–Ni–Mo heterostructure electrocatalyst, prepared by electrodeposition and atomic layer deposition (ALD), was introduced to address these challenges. The electrode was synthesized by electrodepositing a Cu–Ni–Mo coating onto a stainless steel substrate, followed by in-situ sulfurization using ALD technology to form an amorphous layer, yielding a heterostructure with optimized interfacial properties. This heterostructure electrode exhibited an overpotential of 63.29 mV at −10 mA cm −2 and maintained stable operation at −100 mA cm −2 for over 180 h in 0.5 mol/L NaCl +1 mol/L phosphate buffered saline (PBS). A 10 cm × 10 cm electrode was successfully fabricated using this scalable method, which exhibited uniform morphology and stability exceeding 240 h. This work advances HER performance and scalability in neutral environments, facilitating industrial-scale electrocatalytic hydrogen production.