Direct Growth of Platinum Monosulfide Nanoparticles on MXene via Single‐Source Precursor for Enhanced Hydrogen Evolution Reaction

2D Ti 3 C 2 T x MXene offers high electrical conductivity and a large surface area, making it attractive for electrocatalysis. However, its intrinsic hydrogen evolution reaction (HER) activity remains poor due to the lack of active catalytic sites. To activate the otherwise inert surface, platinum monosulfide (PtS) nanoparticles are synthesized directly on Ti 3 C 2 T x nanosheets via thermal decomposition of a single‐source precursor, Pt(dmampS) 2 , in a solution‐based process. This direct growth strategy enables uniform dispersion of PtS nanoparticles and intimate interfacial contact with the MXene surface, without the need for binders or surfactants. The resulting PtS/Ti 3 C 2 T x heterostructure exhibits significantly enhanced HER performance, achieving a low overpotential of −104 mV at a current density of −10 mA cm −2 and a Tafel slope of 48.3 mV dec −1 .