A research team led by the City University of Hong Kong (CityU) has made a revolutionary advance in nanomaterials by successfully developing a highly efficient electrocatalyst that can significantly increase hydrogen production through the electrochemical splitting of water. This breakthrough has great application potential for the clean energy industry.

Professor Zhang Hua, the Herman Hu Professor of Nanomaterials at CityU, and his team have developed an electrocatalyst using transition metal dichalcogenide (TMD) nanoplates with unconventional crystalline phases as supports. The electrocatalyst shows high activity and excellent stability in the electrocatalytic reaction of hydrogen evolution in an acidic environment.

“The result of our study is important in that hydrogen produced by the electrochemical splitting of water is considered one of the most promising forms of clean energy that will replace fossil fuels in the near future, reducing environmental pollution and the greenhouse effect.” said. Professor Zhang.

This important discovery was published in the journal Nature titled “Phase-dependent growth of Pt in MoS”₂ For highly efficient isolation of H₂“.

Professor Zhang said that the key to electrocatalytic water splitting research is the development of highly efficient and stable catalysts. It is crucial to select the appropriate support to improve the activity and stability of the catalysts during the process. As a new two-dimensional (2D) material, TMD nanosheets have attracted great attention among researchers due to their unique physical and chemical properties.

Phase has been found to be an extremely important factor determining the properties and functions of TMD nanosheets. For example, molybdenum disulfide (MoS₂) exhibits normal 2H phase semiconductor properties, while MoS ₂ Unconventional phase 1T or 1T’ shows metallic or semi-metallic properties, hence good conductivity.

However, the fabrication of unconventional phase TMD nanosheets with high phase purity and high quality remains a challenging task. Research on the effect of the TMD crystal phase on the growth of other materials is still in its early stages. In recent years Prof. Zhang’s research group has developed a number of new methods, such as gas-solid reactions and salt-assisted synthesis, and successfully prepared a series of high-phase purity and high-quality TMD crystal materials with unconventional 1T. ‘phase.

Due to their unique semi-metallic properties, these nanomaterials have great potential in optoelectronic devices, catalysis, energy storage and superconductivity applications. In this study, the team successfully developed a new method to prepare TMD nanosheets with unconventional phases. They also investigated the crystal phase-dependent growth of noble metals on 1T′-TMD and 2H-TMD nanosheets.

They found that using conventional 2H-TMD as a template facilitated the epitaxial growth of platinum (Pt) nanoparticles, while the unconventional 1T′-TMD template supported monoatomically dispersed Pt atoms (s-Pt). Based on these findings, the team developed a monolithically dispersed atomic Pt/1T′-phase molybdenum disulfide (s-Pt/1T′-MoS).₂) catalyst.

To overcome the mass transport limitations of platinum-based catalysts in electrocatalytic hydrogen evolution reactions in acidic environment, the team adopted an advanced floating electrode technology for testing.

Experimental results show that s-Pt/1T′-MoS catalyst ₂ It shows a high mass activity of 85±23 A mg _point^-one With -50 mV overvoltage and mass-normalized exchange current density (127 A mg)_point^-one). In addition, the catalyst can operate stably for 500 h in an aqueous proton exchange membrane electrolyzer, indicating a promising application potential.

The team systematically investigated the phase-dependent growth of noble metals on 1T′-TMD and 2H-TMD nanosheets and showed that 1T′-TMD nanosheets can be effective support for catalysts.

Postdoctoral researcher Dr. “The synthesized new electrocatalyst exhibits excellent activity and excellent stability in the electrocatalytic reaction of hydrogen evolution in acidic environment, and will play an extremely important role in the development of clean energy in the future,” said Shi Zhenyu. in the Department of Chemistry and first author of the paper.

The results obtained expanded the field of “phase engineering of nanomaterials” (PEN), opening a new path for the development and synthesis of highly efficient catalysts. Professor Zhang said that in the future, the team will continue to investigate the 1T’-TMD-based catalyst and its prospects in industrial applications to contribute to clean energy and sustainable development.

Corresponding authors are Professor Zhang and Professor Anthony RJ Kuchernak from the Department of Chemistry at Imperial College London. This research project brought together collaborators from universities and research institutes in Hong Kong, mainland China, Singapore and the United Kingdom, demonstrating the importance of international collaboration to achieve scientific breakthroughs. Source