Vacancy-Engineered Interfacial Electrons Modulation in NiCo Hydroxide/MoS2 Heterostructures for Boosted OER Electrocatalysis

Ruiqian Zhang; Binbin Qian; Dantong Zhang; Ceneng Chen; Yong Luo; Ke Xu; Zhi Long; Amir Said; Jianfeng Jiang; Kunfeng Chen; Sridhar Komarneni; Chunlei Yang; Dongfeng Xue

doi:10.1002/smll.73560

Vacancy-Engineered Interfacial Electrons Modulation in NiCo Hydroxide/MoS₂ Heterostructures for Boosted OER Electrocatalysis

Small. 2026 May 8:e73560. doi: 10.1002/smll.73560. Online ahead of print.

Authors

Ruiqian Zhang^{1

2}, Binbin Qian³, Dantong Zhang⁴, Ceneng Chen¹, Yong Luo¹, Ke Xu³, Zhi Long⁵, Amir Said¹, Jianfeng Jiang⁴, Kunfeng Chen⁶, Sridhar Komarneni⁷, Chunlei Yang¹, Dongfeng Xue³

Affiliations

¹ Center For Photonics Information and Energy Materials, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, P. R. China.
² University of Chinese Academy of Sciences, Beijing, P. R. China.
³ Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Shenzhen, P. R. China.
⁴ College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, P. R. China.
⁵ College of Chemistry and Molecular Sciences, Henan University, Kaifeng, P. R. China.
⁶ State Key Laboratory of Crystal Materials, Shandong University, Jinan, P. R. China.
⁷ Materials Research Institute and Department of Ecosystem Science and Management, 204 Energy and the Environment Laboratory, The Pennsylvania State University, University Park, Pennsylvania, USA.

PMID: 42101272
DOI: 10.1002/smll.73560

Abstract

Developing efficient and durable oxygen evolution reaction (OER) electrocatalysts is crucial for sustainable hydrogen production via water electrolysis. Herein, nickel-cobalt hydroxide/molybdenum disulfide heterostructures (NiCo/MoS₂)with discriminatively engineered cationic (NiCo/Mo^vacS₂) and anionic (NiCo/MoS^vac ₂) vacancies for orchestrating electron transfer were constructed to clarify their distinct roles in regulating interfacial electronic properties and OER performance. Experimental and theoretical analyses demonstrate that Mo vacancies significantly enhance interfacial electron transfer. This facilitates the OER kinetics by modulating the adsorption energy of *O intermediate and thereby shifting the potential-determining step from the deprotonation step to the hydroxyl coupling step, which yields a low overpotential of 256 mV at 10 mA cm^-2 and a small Tafel slope of 68.5 mV dec^-1. In contrast, S vacancies promote electron delocalization within MoS₂ but exhibit inferior catalytic enhancement. The Mo-vacancy-modified NiCo/Mo^vacS₂ electrode holds practical application potential in alkaline electrolyzers, achieving 1 A cm^-2 at 2.11 V (60°C) and operating stably for over 300 h. This work highlights the pivotal importance of vacancy type in heterointerfacial design and provides a strategic direction for developing advanced electrocatalysts.

Abstract

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