Urea-assisted synthesis of amorphous molybdenum sulfide on P-doped carbon nanotubes for enhanced hydrogen evolution

Abstract

Amorphous molybdenum sulfide on P-doped carbon nanotubes (MoS x /P-CNTs) composite with an original leaves–branch architecture for hydrogen evolution reaction (HER) is successfully fabricated by urea-assisted synthesis via a facile hydrothermal process. It is found that urea used in the process of preparation played a crucial role in the establishment of this unique structure, where leaves-like MoS x nanosheets are uniformly anchored on P-CNTs substrate. Besides, the optimal amount of MoS x on P-CNTs bundles is investigated in this paper. Due to the synergistic coupling effects of MoS x nanosheets and P-CNTs bundles, as a result, the unique structure maintains abundant active sites, a high electrical conductivity as well as distinctive electrons transport mechanism, which gives the optimum MoS x /P-CNTs composite, a higher activity for HER with an overpotential of 151 mV (vs. RHE) to reach a current density of 10 mA cm−2 and a smaller Tafel slope of 49 mV dec−1. Stability tests indicate that the catalyst exhibits excellent electrochemical durability in 0.5 M H2SO4 solution. We envision that this work could provide new insights into the rational design of MoS x -based electrocatalysts for energy conversion and storage.