Hierarchical Tubular Architecture Constructed by Vertically Aligned CoS2 -MoS2 Nanosheets for Hydrogen Evolution Electrocatalysis.

ABSTRACT

Developing efficient electrocatalysts for the hydrogen evolution reaction (HER) is crucial for establishing a sustainable and environmentally friendly energy system, but it is still a challenging issue. Herein, hierarchical tubular-structured CoS2 -MoS2 /C as efficient electrocatalysts are fabricated through a unique metal-organic framework (MOF) mediated self-sacrificial templating. Core-shell structured MoO3 @ZIF-67 nanorods are used both as a precursor and a sacrificial template to form the one-dimensional tubular heterostructure where vertically aligned two-dimensional CoS2 -MoS2 nanosheets are formed on the MOF-derived carbon tube. Trace amounts of noble metals (Pd, Rh, and Ru) are successfully introduced to enhance the electrocatalytic property of the CoS2 -MoS2 /C nanocomposites. The as-synthesized hierarchical tubular heterostructures exhibit excellent HER catalytic performance owing to the merits of the hierarchical hollow architecture with abundantly exposed edges and the uniformly dispersed active sites. Impressively, the optimal Pd-CoS2 -MoS2 /C-600 catalyst delivers a current density of 10 mA cm-2 at a low overpotential of 144 mV and a small Tafel slope of 59.9 mV/dec in 0.5 m H2 SO4 . Overall, this MOF-mediated strategy can be extended to the rational design and synthesis of other hollow heterogeneous catalysts for scalable hydrogen generation.