Engineering the surface structure of MoS2 to preferentially expose active edge sites for electrocatalysis

Abstract

Controlling surface structure at the atomic scale is paramount to developing effective catalysts. For example, the edge sites of MoS(2) are highly catalytically active and are thus preferred at the catalyst surface over MoS(2) basal planes, which are inert. However, thermodynamics favours the presence of the basal plane, limiting the number of active sites at the surface. Herein, we engineer the surface structure of MoS(2) to preferentially expose edge sites to effect improved catalysis by successfully synthesizing contiguous large-area thin films of a highly ordered double-gyroid MoS(2) bicontinuous network with nanoscaled pores. The high surface curvature of this catalyst mesostructure exposes a large fraction of edge sites, which, along with its high surface area, leads to excellent activity for electrocatalytic hydrogen evolution. This work elucidates how morphological control of materials at the nanoscale can significantly impact the surface structure at the atomic scale, enabling new opportunities for enhancing surface properties for catalysis and other important technological applications.

One‐Dimensional Earth‐Abundant Nanomaterials for Water‐Splitting Electrocatalysts

“…The effect of different morphologies on their catalytic activities has also been studied for a variety of earth‐abundant HER electrocatalysts, such as MoS 2 ,41, 42, 43 amorphous MoS 2 ,44 WS 2 ,45, 46 Ni 2 P,47 CoP48 and Ni‐Mo alloys 49, 50. In 2014, Jin and coworkers reported the synthesis of metallic cobalt pyrite (cobalt disulfide, CoS 2 ) with different morphologies including films, microwires and nanowires, and showed their capabilities as a high‐activity candidate for HER 27.…”

Face the Edges: Catalytic Active Sites of Nanomaterials

“…This alternative strategy may open new gate for catalyst design. The second rule seems easier to achieve: Jaramillo group synthesized a highly ordered double‐gyroid MoS 2 bicontinuous network with nanoscale pores, the high surface curvature exposes abundant edges47; Xie group prepared defect‐rich MoS 2 nanosheets which force the formation of edges (Figure 2b) 48. As for enhancing the conductivity, Dai group fabricated a strong coupling MoS 2 –graphene sheets, and the conducting network facilitate the catalytic reaction (Figure 2a) 49…”

Nickel Hydr(oxy)oxide Nanoparticles on Metallic MoS2 Nanosheets: A Synergistic Electrocatalyst for Hydrogen Evolution Reaction

“…Extensive efforts have been made to improve the HER activities of MoS 2 ‐based catalysts in acidic media by strategies such as nanostructure engineering,35, 36, 37, 38 defect engineering,39, 40, 41, 42, 43 phase engineering,44, 45, 46, 47, 48 and heteroatom doping49, 50, 51 to increase the number or enhance the intrinsic activity of active sites. However, little work has been reported to improve the HER activities of MoS 2 ‐based materials in alkaline media 31, 52.…”