Carbon nanotubes encapsulating Pt/MoN heterostructures for superior hydrogen evolution.

ABSTRACT

Achieving efficient hydrogen evolution reaction (HER) catalysts to scale up electrochemical water splitting is desirable but remains a major challenge. Here, nitrogen-doped carbon nanotubes (NCNTs) loaded with PtNi/MoN electrocatalyst (PtNi/MoN@C) is synthesized by a simple strategy to obtain stronger interphase effects and significantly improve HER activity. The surface morphology of the materials is altered by Pt doping and the electronic structure of MoN is changed, which optimizing the electronic environment of the materials, shifting the binding energy and giving the materials a higher electrical conductivity, this ultimately leads to faster proton and electron transfer processes. The synergistic effect of Pt nanoparticles, MoN and the good combination with carbon leads to a high HER activity of 18 mV to reach 10 mA cm-2 in alkaline solution, outperforming that of the commercial Pt/C. Theoretical studies show that the heterostructures can efficiently enhance the electron transport and reduce the △GH*.