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 c...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.展开更多
基金We thank Ann F. Marshall and Ai Leen Koh for TEM expertise and support. TEM imaging was performed at the Stanford Nanocharacterization Laboratory. This work was partially supported by the Stanford Precourt Institute of Energy. C. L. C. was supported by the National Science Foundation （Award No. CHE-1137395）. R. T. acknowledges the support of the EU-ITN project MoWSeS （317451）. He holds the Drake family chair in Nanotechnology and is the director of the Helen and Martin Kimmel Center for Nanoscale Science.
文摘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.
