Guowei Li
Max Planck Institute for Chemical Physics of Solids, Germany
Title: Interfacially engineering topological semimetal MoP into a superior electrocatalyst for hydrogen evolution
Biography
Biography: Guowei Li
Abstract
Materials in topological states are endowed with many exotic properties such as extremely large magnetoresistance, high conductivity, and intrinsic Hall effects. However, the effect of such appealing properties on electrocatalysis still remains elusive. Recently, the observation of exceedingly high conductivity and Weyl nodes in MoP provide us with a modeling catalyst for revealing the correlation between topological states and electrocatalytic activity and designing high-performance electrocatalyst for hydrogen evolution reaction (HER). MoP encapsulated in Mo, P co-doped carbon layer (MoP@C) was thus synthesized and exhibits outstanding electrocatalytic HER performance with an extremely low overpotential of only 49 mV at a current density of 10 mA/cm2 and a decreased Tafel slope of 54 mV/dec. in alkaline medium. Such superior HER activity of the MoP@C exceeds those of the-state-of-art non-noble metal-based HER electrocatalysts and even comparable to that of the Pt/C catalyst. As a topological semimetal, MoP manifests a very high conductivity (8.2 μΩ at 300 K) and mobility (up to 10 cm2/VS at 300 K) due to the topologically protected triple point fermions and complex Fermi surface. Meanwhile, the rich P-C and Mo-C bonds in the interfaces between the carbon layer and MoP modulates the band structure of MoP@C and eventually facilitates the fast electron transfer, accumulation, and subsequent de-localization, which are responsible for the excellent HER activity.