Combining Highly Dispersed Amorphous MoS₃ with Pt Nanodendrites as Robust Electrocatalysts for Hydrogen Evolution Reaction

Abstract Surface modification of electrocatalysts to obtain new or improved electrocatalytic performance is currently the main strategy for designing advanced nanocatalysts. In this work, highly dispersed amorphous molybdenum trisulfide‐anchored Platinum nanodendrites (denoted as Pt‐a‐MoS₃ NDs) are developed as efficient hydrogen evolution electrocatalysts. The formation mechanism of spontaneous in situ polymerization MoS₄²⁻ into a‐MoS₃ on Pt surface is discussed in detail. It is verified that the highly dispersed a‐MoS₃ enhances the electrocatalytic activity of Pt catalysts under both acidic and alkaline conditions. The potentials at the current density of 10 mA cm⁻² (η₁₀) in 0.5 m sulfuric acid (H₂SO₄) and 1 m potassium hydroxide (KOH) electrolyte are −11.5 and −16.3 mV, respectively, which is significantly lower than that of commercial Pt/C (−20.2 mV and −30.7 mV). This study demonstrates that such high activity benefits from the interface between highly dispersed a‐MoS₃ and Pt sites, which act as the preferred adsorption sites for the efficient conversion of hydrion (H⁺) to hydrogen (H₂). Additionally, the anchoring of highly dispersed clusters to Pt substrate greatly enhances the corresponding electrocatalytic stability.