Growth of Semi-metallic Transition Metal Dichalcogenides on Amorphous Materials for Highly Efficient Hydrogen Evolution

Water electrolysis using highly efficient electrocatalysts has been considered a promising strategy for producing green H2. Two-dimensional (2D) transition metal dichalcogenides (TMDs) are promising electrocatalysts for hydrogen evolution reaction (HER) due to their large surface area, and abundant active sites. As a newly emerging strategy, phase engineering of nanomaterials (PEN) enables the precise control of the atomic arrangements of TMDs to tune their catalytic activities. Importantly, semi-metallic 1T′-MoS2 exhibits superior HER performance compared to the semiconducting 2H-MoS2 due to its higher basal-plane activity and greater intrinsic electrical conductivity. Hence, synthesis of semi-metallic TMDs for electrocatalytic HER is of great significance. Crystalline metal substrates/templates have been used for synthesizing high-quality TMDs. Unfortunately, the as-synthesized TMDs normally possess 2H phase, or mixed 2H and 1T′ phases. Additionally, the metastable 1T′ phase could gradually transform into the thermodynamically stable 2H phase, severely hindering the study of intrinsic catalytic activities and phase-dependent HER performances of the semi-metallic TMDs. Recently, our group has published a work in Nature Materials, proposing a facile and general wetchemical method to grow a series of semi-metallic 1T′-TMD monolayers with high phase purity and stability on 4H-Au nanowires, in which the key role of the crystal phase of metal substrates/templates in the controlled synthesis of TMDs with unconventional phases was emphasized. Besides the crystalline metal substrates/templates, amorphous nanostructures could also be used as ideal substrates/templates to grow secondary materials. In addition, amorphous nanostructures are highly efficient catalysts for HER due to the abundant unsaturated coordination sites compared to their crystalline counterparts. Therefore, it is believed that synthesis of semi-metallic 1T′-TMDs on amorphous templates to construct hybrid nanomaterials could exhibit superior HER performance by virtue of the intrinsic catalytic HER activity of amorphous nanostructures and semi-metallic 1T′-TMDs. In this proposal, we aim to develop facile and general synthetic strategies to grow various semi-metallic 1T′-TMDs on amorphous templates to construct novel amorphous metal/semi-metallic TMD hybrid nanomaterials (denoted as a-M/sm-TMDs). Some key fundamental issues will be addressed in this proposal, including the growth and stabilization mechanism of semi-metallic TMDs on amorphous templates, the synergistic effect between amorphous metal and semi-metallic TMDs on the HER performance, and the structure-performance relationship in a-M/sm-TMD hybrid nanomaterials towards HER.