posted on 2020-07-07, 14:47authored byKyungju Nam, Hoje Chun, Jeemin Hwang, Kyung-Ah Min, Byungchan Han
We screen optimum
bilayer pairs of transition metal dichalcogenides
(TMDs) and doped graphene (G) for highly active and stable catalysts
of the hydrogen evolution reaction (HER). Based on first-principles
density functional theory (DFT) calculations and ab initio thermodynamic
formalisms, we propose a new design concept for active and durable
HER catalysis with cost-effective materials. Specifically, we discover
that the dual interfaces of the bilayer in NbS2 and supported
6% B-doped G systems can be highly activated. The design is especially
useful for HER catalysis in a vertically oriented architecture of
the material. The Gibbs free energy landscape of the TMD/G pairs for
the HER demonstrates that the thermodynamic performance is comparable
or superior to conventional platinum on carbon (Pt/C). The stability
of the catalyst is evaluated by two descriptors: interface adhesion
energy of the pair and defect formation energy of sulfur (S) in the
TMD surface. Our results provide new concepts for how to enhance catalytic
activity and durability via hybrid interfacing of cost-effective materials,
essentially leading to overcoming conventional challenges for Pt-based
catalysts.