Enhanced hydrogen evolution reaction on few–layer MoS2 nanosheets–coated functionalized carbon nanotubes

Abstract

The oxygen– or nitrogen–functionalized multiwalled carbon nanotubes (O– or N–MWCNT) coated with few–layer MoS2 nanosheets (MoS2/MWCNTs) were successfully synthesized by a facile hydrothermal method. The results suggest that the N–MWCNT is favorable for the dispersion of few–layer MoS2 nanosheets due to the strong interaction between the N-containing groups and Mo precursor. The N–MWCNT coated with few–layer MoS2 (MoS2/N–MWCNT) exhibits the highest HER activity: onset potential of 90 mV vs. reversible hydrogen electrode, Tafel slope of 40 mV dec−1, high current density of 80.3 mA cm−2 at overpotential 0.2 V, together with excellent stability during 10,000 cycles. Such high HER activity is superior to most of MoS2–based catalysts reported so far, and attributed to the intimate contacts between highly conductive network of N–MWCNT and thin MoS2 nanosheets, the high quantity of unsaturated sulfur atoms or the bridging S22−, and high pyridinic and graphitic N concentrations. This work shows that the few–layer MoS2 nanosheets coated on conductive N–doped MWCNT has a great potential for electrocatalytic hydrogen evolution.