Incorporation of tungsten nanoparticles on WS2 film for the enhanced hydrogen evolution
Ruijing Wang, De Zhang, Sijia Luo, Qunlong Wang, Lijuan Jiang, Guangfeng Wei, Xuefeng Wang
Abstract
As a promising catalyst for electrochemical hydrogen evolution reaction (HER), WS 2 is currently focused due to its low cost and highly intrinsic activity. In this work, a 2H WS 2 film with metal W nanoparticles (W-WS 2 ) on the carbon cloth is constructed by the high-vacuum pulsed laser deposition under the in-situ heating condition. The uniform distribution of WS 2 provides abundant active sites, and a higher crystallinity with the incorporation of metal W nanoparticles on the W-WS 2 film effectively provides abundant electron on the S-edge. By combining the experiment and density functional theory calculations, it is found that the formation of a primary redox pair between metal W and S-edge on WS 2 makes the oxidation happen on the W nanoparticles , thus protecting the active S-edge sites. Finally, this typical W-WS 2 film shows an overpotential of 210 mV at the current density of 10 A cm −2 in 0.5 M H 2 SO 4 , which is superior to the commercial WS 2 powder (526 mV) or pure WS 2 film (341 mV).