Yttrium-doped NiMo-MoO<sub>2</sub> heterostructure electrocatalysts for hydrogen production from alkaline seawater.

Liu, Shujie; Zhang, Zhiguo; Dastafkan, Kamran; Shen, Yan; Zhao, Chuan; Wang, Mingkui · Nat Commun · 2025

basic_science · Level V

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Abstract

Active and stable electrocatalysts are essential for hydrogen production from alkaline water electrolysis. However, precisely controlling the interaction between electrocatalysts and reaction intermediates (H<sub>2</sub>O*, H*, and *OH) remains challenging. Here, we demonstrate an yttrium-doped NiMo-MoO<sub>2</sub> heterogenous electrocatalyst that efficiently promotes water dissociation and accelerates the intermediate adsorption/desorption dynamics in alkaline electrolytes. Introducing yttrium into the NiMo/MoO<sub>2</sub> heterostructure induces lattice expansion and optimizes the d-band center of NiMo alloy component, enhancing water dissociation and H* desorption. Yttrium doping also increases the concentration of oxygen vacancies in MoO<sub>2-x</sub>, which in turn accelerates the charge kinetics and the swift evacuation of *OH intermediates from the active sites. Consequently, the Y-NiMo/MoO<sub>2-x</sub> heterostructure exhibits notable performance by requiring only 189 and 220 mV overpotentials to achieve current density of 2.0 A cm<sup>-2</sup> in alkaline water and seawater, respectively. This work provides a strategy to modulate heterostructure catalysts for scalable, economically viable hydrogen production from low-quality waters.