Constructing CoS nanosheets on Ti3C2 MXenes for boosting hydrogen evolution reactoion

Hydrogen production via electrocatalytic water-splitting requires highly-active and less-expensive catalyst for the hydrogen evolution reaction (HER). Herein, a novel nanohybrid by upright growing CoS nanosheets on the surface of the Ti3C2 MXenes (CoS@Ti3C2) are prepared through hydrothermal process. The optimal CoS@Ti3C2 nanohybrid exhibits typical nanoflower shape, in which the Ti3C2 MXene not only effectively prevents the CoS nanoparticles from aggregation, but also improves the conductivity and the charge transfer. Furthermore, the heterogeneous interfaces formed between CoS and Ti3C2 and the synergistic effects between the individual components ultimately boost the formation of Hads intermediates in the Volmer step. Beneficially, the CoS@Ti3C2 nanohybrid exhibits an optimal overpotential of 121 mV at 10 mA·cm−2, low Tafel slope of 100 mV dec−1, and a steady catalytic behavior over 12 h in 0.5 M H2SO4.