  Molybdenum Disulfide (MoS$_2$) has been recognized as a potential
substitution of Platinum (Pt) for electrochemical hydrogen evolution reaction
(HER). However, the broad adoption of MoS$_2$ is hindered by its limited number
of active sites and relatively low inherent electrical conductivity. In this
work, we demonstrated a synergistic enhancement of both active site exposure
and electrical conductivity by a one-step solvothermal synthesis technique. The
1T-phase enriched MoS$_2$ was directly formed on the titanium carbide
(Ti$_3$C$_2$Tx, MXene) with carbon nanotubes (CNTs) acting as crosslinks. The
existence of edge-enriched metallic phase MoS$_2$, the conductive backbone of
MXene along with the crosslinking function of CNTs clearly improved the overall
electrical conductivity of the catalyst. Moreover, the integration of
two-dimensional (2D) MoS$_2$ with MXene effectively suppressed the MXene
oxidation and 2D layer restacking, leading to good catalytic stability. As a
result, an overpotential of 169 mV and a low Tafel slope of 51 mV/dec was
successfully achieved. This work provides a new route for 2D-based
electrocatalyst engineering and sheds light on the development of the
next-generation PGM-free HER electrocatalysts.
