Researchers at Hongik have unveiled a general phase engineering–based materials design strategy to overcome the durability limits of non-noble-metal catalysts for water splitting. Their findings, published in the Journal of the American Chemical Society (JACS) in October 2025, report that defect-engineered molybdenum telluride (MoTe₂) integrated with nickel hydroxide (Ni(OH)) domains achieves oxygen evolution reaction (OER) performance and long-term stability that surpass even those of iridium oxide (IrOₓ), a benchmark precious-metal catalyst.

Water splitting—the process of converting water into hydrogen and oxygen—is a cornerstone of clean hydrogen production but is limited by the sluggish oxygen evolution reaction, which requires multiple electron–proton transfer steps. Transition metal dichalcogenides like MoTe₂ offer superior conductivity compared to traditional oxides, but they often degrade under oxidative conditions.

The research team led by Prof. Won-Kyu Lee addressed this challenge by engineering phase transitions in MoTe₂to create a heterostructure rich in active boundary regions. Controlled dissolution of tellurium atoms induced a partial transition from the semiconducting 2H phase to the metallic 1T′ phase, enabling the selective nucleation of Ni(OH)₂ nanoparticles at defect and interfacial sites. This deliberate phase engineering coupled with rational materials design produced a robust catalytic interface that promotes both efficiency and stability.

“Our work shows that strategic phase engineering and materials design can fundamentally transform catalyst performance,” said Prof. Won-Kyu Lee, corresponding author of the study. “Furthermore, by combining machine-learning-based interatomic potentials with density functional theory, we established a theoretical framework that can provide general design principles for complex heterogeneous catalytic systems, such as phase boundaries and multicomponent interfaces. This approach paves the way for scalable, durable, and cost-effective catalysts for green hydrogen production.”

Elemental maps of the MoTex/Ni(OH)2 Heterostructured Electrocatalysts for Oxygen Evolution Reaction

[Reference] J. Han et. al., “Efficient and Stable Electrocatalytic Oxygen Evolution from MoTex/Ni(OH)2 Heterostructures,” Journal of the American Chemical Society 2025

[Main Author] Junwhi Han (Hongik University), Won-Kyu Lee (Hongik University)

* Contact email : Professor Won-Kyu Lee (wklee@hongik.ac.kr)