Surface extension of MeS2 (Me=Mo or W) nanosheets by embedding MeSx for hydrogen evolution reaction

초록

Two-dimensional transition metal dichalcogenides (2D-TMDs), such as MoS2 and WS2 nanosheets (MeS2-NS), are reported as efficient catalysts for hydrogen evolution reaction (HER), which can potentially replace the expensive platinum catalyst. In this report, IT phase MeS2 (1T-MeS2) NS are synthesized by lithium-intercalation exfoliation method, subsequently being modified by amorphous MoSx and WSx (MeSx@MeS2-NS) through a solvothermal method. Interestingly, MeSx@MeS2-NS significantly improves the HER performance compared with bare MeS2-NS as catalysts. Among these, MoSx@MoS2 is observed to be the best combination for HER, with an onset potential and Tafel slope of 114 mV and 45.1 mV decade(-1), respectively. The enhancement in the HER device using MeSx@MeS2-NS as the catalyst originates from vertically grown MeSx, which provides additional active sulfur sites for the reaction, while inhibiting the restacking of MeS2-NS. Furthermore, MoSx@MoS2-NS shows stable catalytic properties for HER after the 1000 cyclic test, without any observable changes. Thus, this study presents a facile method for the synthesis of 2D-TMD catalyst for HER towards large-scale and long-term stability for practical application. (C) 2018 Elsevier Ltd. All rights reserved.

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