Efficient and scalable preparation of MoS2 nanosheet/carbon nanotube composites for hydrogen evolution reaction

An efficient and scalable method combining ball-milling and liquid-phase exfoliation was used to prepare MoS 2 nanosheets . Ammonium bicarbonate as an exfoliation aid could accelerate the delamination and pulverization of bulk MoS 2 during preparation. The ball-milled MoS 2 was further exfoliated by sonication (S–MoS 2 NS) or high-speed shear-exfoliation (H–MoS 2 NS) to obtain MoS 2 nanosheets dispersion with high concentration. Moreover, MoS 2 quantum dots were also obtained by prolonging sonication time (S–MoS 2 QS). Most of S–MoS 2 NS and H–MoS 2 NS have lateral dimensions less than 150 nm. The S–MoS 2 QS size concentrates at around 5 nm. The H–MoS 2 NS mixed with aminated multi-walled carbon nanotubes (MWCNT) could form H–MoS 2 NS/MWCNT composites with a good conductive network, and was used as a hydrogen evolution reaction (HER) catalyst. The H–MoS 2 NS/MWCNT composites containing 56 wt% H–MoS 2 NS exhibited a favorable HER activity with a low overpotential of 284 mV at 10 mA/cm 2 , a Tafel slope of 97 mV/dec and good stability in acid medium.