A research team led by City University of Hong Kong (CityU) has made significant progress in the field of nanomaterials by developing a highly efficient electrocatalyst capable of significantly improving hydrogen production through water electrolysis.
This major discovery offers significant application potential for the clean energy industry.
The development of an innovative electrocatalyst
Professor Zhang Hua, Herman Hu Chair in Nanomaterials at CityU, and his team developed an electrocatalyst using transition metal dichalcogenide nanosheets (TMD) with unconventional crystalline phases as supports.
The electrocatalyst exhibits superior activity and excellent stability in the electrocatalytic hydrogen evolution reaction in acidic medium.
“ Our discovery is important as hydrogen produced by water electrolysis is considered one of the most promising clean energies to replace fossil fuels in the near future, thereby reducing environmental pollution and the effect of tight said Professor Zhang.
Publication of results in the journal Nature
This important discovery was published in the prestigious journal Nature under the title “Phase-dependent growth of Pt on MoS2 for highly efficient H2 evolution”.
Professor Zhang pointed out that the key to water electrolysis research lies in the development of highly efficient and stable catalysts. It is essential to choose an adequate support to improve the activity and stability of the catalysts during the process.
TMD nanosheets and their unique properties
As an emerging two-dimensional (2D) material, TMD nanosheets have attracted great interest among researchers due to their unique physical and chemical properties.
It was found that phase is an extremely important factor that determines the properties and functions of TMD nanosheets.
For example, molybdenum disulfide (MoS2) with the conventional 2H phase shows a semiconductor property, while MoS2 with the unconventional 1T or 1T′ phases shows a metallic or semi-metallic property, thus possessing good conductivity.
-An innovative method to prepare TMD nanosheets
In this research, the team successfully developed a new method to prepare TMD nanosheets with unconventional phases. They also studied the phase-dependent growth of noble metals on 1T′-TMD and 2H-TMD nanosheets.
They found that using conventional 2H-TMD as a template, it facilitates the epitaxial growth of platinum (Pt) nanoparticles, while the unconventional 1T′-TMD template supports monatomically dispersed Pt atoms (s- Pt).
A promising catalyst for hydrogen evolution
Based on these results, the team developed the catalyst based on 1T′ phase molybdenum disulfide and monatomically dispersed platinum atoms (s-Pt/1T′-MoS2). To overcome the mass transport limitation of Pt-based catalysts in electrocatalytic hydrogen evolution reactions in acidic media, the team adopted advanced floating electrode technology for testing.
Their experimental results showed that the s-Pt/1T′-MoS2 catalyst exhibited a high mass activity of 85±23 A mgPt-1 at an overpotential of -50 mV and a normalized mass exchange current density (127 A mgPt -1).
In addition, the catalyst can work stably for 500 hours in a proton exchange membrane water electrolyzer, showing promising application potential.
Synthetic
The results of this study broadened the scope of “ phase engineering of nanomaterials » (PEN), opening a new avenue for the design and synthesis of highly efficient catalysts.
Professor Zhang said that in the future, the team will continue research on 1T′-TMD-based catalysts and their industrial application prospects, so as to contribute to clean energy and sustainable development.
Main illustration caption: Professor Zhang Hua, Herman Hu Chair in Nanomaterials at CityU, and his team recently developed a highly efficient electrocatalyst that can significantly improve hydrogen production through electrochemical water splitting . Credit: City University of Hong Kong
Reference “Phase-dependent growth of Pt on MoS2 for highly efficient H2 evolution” – DOI: 10.1038/s41586-023-06339-3
[ Rédaction ]
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