A nanoarchitectured 2D–2D heterointerface of Pt@Ti3C2Tx–rGO aerogels via in situ γ-radiolysis induced self-assembly: interplay between strain and ligand effects in electrocatalytic interfaces

Abstract

Achieving high-performance and cost-effective Pt-based catalysts with low Pt content and thereby boosting Pt utilization remains a significant challenge in the field of oxygen and hydrogen electrocatalysis. The authentic performance of Pt is often hindered by the occupancy and poisoning of active sites, weak Pt–support interaction, and the degradation of catalysts. To address these issues, we demonstrate a rational design of a low Pt loaded 3D porous aerogel support through self-assembly and reduction of a 2D–2D heterostructure comprising MXene (Ti₃C₂T_x) and reduced graphene oxide (rGO) via a γ-radiolytic synthesis process. The aerogel heterointerface effectively prevents Ti₃C₂T_x restacking and aggregation, thereby enhancing the interaction of the electrocatalyst with the electrolyte. Through precise regulation of the heterojunction interface with a strong metal–support interaction (SMSI), the Pt@Ti₃C₂T_x–rGO catalyst demonstrates excellent electrocatalytic performance for the HER, OER, and ORR. The Pt@Ti₃C₂T_x–rGO catalyst exhibits efficient ORR activity, with a high onset potential of 0.957 V, and low overpotentials for the HER (43 mV) and OER (490 mV) at a current density of 10 mA cm⁻², as well as excellent stability against degradation under acidic conditions. Furthermore, we studied the role of the electronic effects (ligand and strain) induced by SMSI. Spectroscopic analysis confirms that the observed downward shift in the Pt d-band center, attributed to both charge transfer from the support to Pt and compressive strain exerted on the Pt lattice, is responsible for the enhanced electrocatalytic activity. This work successfully offers strategic guidance for charge transfer and strain equilibration in heterointerfaces toward the rational design of advanced electrocatalysts.