Alkaline water splitting has the advantages of low cost, long lifetime and ease of maintenance, and is widely applied commercially. However, the sluggish kinetics of HER inhibits the further development of alkaline water splitting. Though noble catalysts can greatly boost the process of HER, they are hard to meet the requirement of industrial production due to the high price and scarcity. Thus, it is urgent to develop low cost and highly efficient catalysts for alkaline water splitting.
A team of material scientists led by Qiang Wang and Shuang Yuan from Northeastern University in Shenyang, China recently have provided a novel strategy for modulating crystalline-amorphous composites and electronic structures to enhance the hydrogen evolution reaction. Through the electrodeposition method, they successfully synthesized the NiMo-NiMoOx electrocatalyst with crystalline-amorphous heterointerface. Theoretical calculations and experimental results confirm that the introduction of Mo atoms can not only lower the energy barrier of water dissociation and optimize the capacity for hydrogen adsorption/desorption, but also modulate the ratio between crystalline and amorphous phase, increasing the heterostructure interfaces and enriching active sites. As a result, NiMo-NiMoOx electrocatalyst exhibits remarkable HER catalytic properties and durability. It requires a low overpotential of 30 mV at the current density of 10 mA cm-2 in 1.0 M KOH, as well as a long-term stability with slight degradation after operating for over 80 h. Moreover, it also exhibits excellent activity and stability with negligible declination in the simulated alkaline seawater, making it highly promising for seawater electrolysis applications.
The team published their article in Nano Research on April 18, 2025.
Nickel-based transition metal catalysts are promising for large-scale hydrogen production due to their abundance and low cost. Ni-NiO catalysts exhibit good activity for the synergistic effect between Ni and NiO component and strong electronic coupling effect on the heterostructure interface. However, it still far away from precious metal catalysts. Therefore, it is of great significance to modulate the electronic structure of the Ni-NiO heterostructure interface to optimize intermediate adsorption energy for enhancing catalytic activity.
Recently, phase and interface engineering via crystalline-amorphous heterostructures has become an attractive strategy for fabricating highly active HER electrocatalysts due to the synergistic effect and intriguing phase properties. Compared to the crystalline phase, the amorphous phase exhibits a distinctively disordered atomic arrangement with abundant defects and unsaturated coordination environments, providing more active site. In addition, the isotropic and flexible properties of the amorphous phase enable an easily adjustable local electronic structure at the active sites, which can optimize the intermediates' adsorption/dissociation capability. The crystalline phase, on the other hand, possesses high electrical conductivity and lower metal ion leaching. Thus, the integration of the crystalline phase with the amorphous phase can improve the electrical conductivity and stability of the catalysts, which are the shortcomings of the amorphous phase.
Although there are studies on constructing crystalline-amorphous heterostructures for hydrogen evolution reaction catalysts, the focus has been on designing the crystalline-amorphous compositions, while the ratio of compositions on the catalytic performance has been neglected. Additionally, the synthesis process for crystalline-amorphous electrocatalysts is often complex, typically involving heat treatment or acid/alkali soaking. We have directly synthesized the NiMo-NiMoOx crystalline-amorphous electrocatalyst via a one-step electrodeposition method, which is simple and mild. Moreover, by adjusting the Mo content, we can control the ratio between the crystalline and amorphous phases and the charge distribution at the heterojunction, thereby enhancing the catalyst's activity.
The research team expects this study will spur the development of crystalline-amorphous heterostructure electrocatalysts. Such crystalline-amorphous heterostructures are common in the catalysts. For example, the surface reconstruction may eventually result in crystalline-amorphous heterostructure. Thus, it is of great significance to pay attention to the study of the crystalline-amorphous heterostructure.
Other contributors include Xinjia tan, Zhong Wang, Jiaqi Liu and Jinshuo Yang from the School of Metallurgy at Northeastern University in Shenyang, China; and Qiang Wang from the Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education) at Northeastern University.
This work was financially supported by the National Natural Science Foundation of China (No. 52274294) and the Liaoning Province Science and Technology Plan Joint Program (Key Research and Development Program Project) (No. 2023JH2/101800058).
About the Authors
Prof. Shuang Yuan is a full professor in the School of Metallurgy at Northeastern University, China. His research interests focus on the structural control of materials under magnetic fields and their battery and electrocatalytic performance. Until now, he has published more than 80 papers in Advanced Materials, Energy & Environmental Science and other journals, presided over 10 national/provincial scientific research projects.
Prof. Qiang Wang is a full professor in the Key Laboratory of Electromagnetic Processing of Materials (Ministry of Education) at Northeastern University, China. Vice President of Northeastern University. His research interests focus on the preparation and processing of metal materials in external fields, energy conversion materials and technologies. Until now, he has published more than 400 papers in Advanced Materials and other journals, presided over 60 national/provincial scientific research projects. Received one National Second Prize for Progress in Science and Technology.
For more information, please pay attention to our homepage:
http://team.neu.edu.cn/MMPCEF/zh_CN/index/155586/list/index.htm.
About Nano Research
Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 7,000 articles. In 2024 InCites Journal Citation Reports, its 2024 IF is 9.0 (8.7, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.
END