MOFs-derived hybrid nanosheet arrays of nitrogen-rich CoS2 and nitrogen-doped carbon for efficient hydrogen evolution in both alkaline and acidic media.

Abstract Rational design of highly active, economical and stable electrocatalysts for hydrogen evolution reaction (HER) is still a great challenge for future applications. Herein, we use a 2D metal-organic framework array as the reactive template and precursor, to fabricate a hybrid nanosheet array of nitrogen-rich CoS 2 @nitrogen-doped carbon on Ti foil substrate (N–CoS 2 @NC/Ti) through a simple thermal treatment in the presence of thiourea. Owing to the prominent synergistic effect of the coupling between CoS 2 and NC, a high content of Co-N x species as well as unique nanoarray architectures, the as-synthesized N–CoS 2 @NC/Ti electrode exhibits remarkable activity and robust durability for HER under both acidic and alkaline conditions, which is obviously superior to the CoS 2 @NC/Ti. Graphical abstract Image 1 Highlights • A novel 2D Co-MOFs was used to fabricate N–CoS 2 @NC flake arrays. • The N–CoS 2 @NC/Ti has a high content of Co-Nx species. • Outstanding HER performance was achieved in acidic and alkaline medium. [ABSTRACT FROM AUTHOR]