Interfacial Electronic and Geometric Modulation in Pt/MoS2–rGO Nanoparticles for Enhanced Methanol Oxidation Reaction and Hydrogen Evolution Reaction

Abstract

Maximizing Pt utilization while maintaining high activity and durability remains a central challenge in designing next-generation fuel cell electrocatalysts. In this work, a Pt/MoS2-rGO nanocomposite is developed to be anchored within a preformed 3D MoS2-rGO aerogel, exploiting cooperative electronic and structural effects. During Pt deposition, mild chemical reduction with ascorbic acid simultaneously forms ultrafine Pt nanoparticles and partially reduces GO to rGO, yielding a conductive, robust, and interconnected framework that prevents nanosheet restacking and promotes efficient electron transport. The aerogelic architecture enables uniform Pt dispersion and strong interfacial bonding with MoS2 and rGO, thereby increasing active site accessibility and minimizing aggregation. Advanced techniques such as X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) reveal measurable charge redistribution at the Pt-MoS2-rGO interface, which alters Pt electronic states and accelerates catalytic kinetics. The resulting catalyst exhibits high methanol oxidation activity (forward peak current density of 39.8 mA cm–2), low HER overpotential (50 mV at 10 mA cm–2), and stable electrochemical performance during prolonged operation. This study highlights a versatile support-engineering strategy in which synergistic geometric and electronic interactions within a 3D hybrid aerogel significantly enhance the intrinsic activity, stability, and Pt utilization of nanostructured electrocatalysts.