Enhancing Broad-pH Hydrogen Evolution via Synergistic Interface and Proton Dynamics Engineering in Pt-MoS2/NHMCS Heterostructure

Developing broad-pH hydrogen evolution reaction (HER) catalysts is crucial for green hydrogen production. Herein, Pt-MoS 2 heterostructure catalysts supported on nitrogen-doped hollow mesoporous carbon spheres (NHMCS) were synthesized via a two-step microwave-assisted solvothermal strategy. The catalyst exhibits outstanding HER activity in acidic, alkaline, and neutral electrolytes, especially in neutral conditions. Pt-MoS 2 /NHMCS-15 mg delivers a current density of 10 mA cm −2 at an ultralow overpotential of only 5.5 mV in 1.0 m PBS. Negligible performance degradation occurs after 100,000 cyclic voltammetry (CV) cycles and 120 h chronoamperometric operation, showing outstanding stability. X-ray absorption fine structures (XAFS), in situ Raman spectroscopy combined with density functional theory (DFT) calculation, elucidate the origin of the enhanced HER activity in neutral media. Strong metal-support interactions (SMSI) at the Pt-MoS 2 interface significantly lower the dissociation energy barrier of the P─OH bond in H 2 PO 4 – , thereby facilitating proton release. Simultaneously, neutral conditions yield higher hydrogen coverage on Pt sites than acidic or alkaline media. These findings provide fundamental insights into the intrinsic mechanism governing the broad-pH HER performance of Pt-MoS 2 /NHMCS-15 mg, particularly in neutral electrolytes, and offer valuable theoretical and experimental guidance for the rational design of efficient and cost-effective HER catalysts, advancing the practical implementation of electrocatalytic hydrogen evolution technologies.