WS2 nanoflakes from nanotubes for electrocatalysis
tungsten disulfide, nanotubes, nanostructuring, hydrogen evolution
ABSTRACT Next-generation catalysts for water splitting are crucial towards a renewable hydrogen economy. MoS2 and WS2 represent earth-abundant, noble metal cathode alternatives with high catalytic activity at edge sites. One challenge in their development is to nanostructure these materials in order to achieve increased performance through the creation of additional edge sites. In this work, we demonstrate a simple route to form nanostructured-WS2 using sonochemical exfoliation to break interlayer and intralayer bonds in WS2 nanotubes. The resulting few-layer nanoflakes are ~100 nm wide with a high density of edge sites. WS2 nanoflakes are utilized as cathodes for the hydrogen evolution reaction (HER) and exhibit superior performance to WS2 nanotubes and bulk particles, with a lower onset potential, shallower Tafel slope and increased current density. Future work may employ ultra-small nanoflakes, dopant atoms, or graphene hybrids to further improve electrocatalytic activity.
Tsinghua University Press
Charina L. Choi,Ju Feng,Yanguang Li,Justin Wu,Alla Zak,Reshef Tenne,Hongjie Dai, WS2 nanoflakes from nanotubes for electrocatalysis. NanoRes.2013, 6(12): 921–928