Synergistic Interfacial Engineering in V2C MXene Heterostructures for Enhanced Nano-aluminum Reactivity

Nano-aluminum (nano-Al) is a high-energy-density material with exceptional reactivity, making it promising for aerospace and military applications. Reducing particle size increases the active surface area and interfacial mass diffusion, but intrinsic agglomeration and dense alumina shells hinder diffusion. Conventional additives often reduce reactivity. Here, we modulate nano-Al interfacial diffusion through synergistic interactions in a V2C MXene heterostructure. The self-assembly of nano-Al on MXene suppresses agglomeration, while fluorine-containing terminations etch the alumina shells. The heterostructure also forms metal oxide contact layers that promote solid-phase thermite reactions. These effects increase the peak heat flow in air to 107.6 W g-1, 3.5 times that of pristine nano-Al. Solid-phase reactions complete energy release before Al melting, minimizing energy loss. The composite shows larger flame areas and a lower minimum ignition concentration (≥5 wt %). Adjusting the heating temperature reduces the total combustion duration by 88.9% and increases the dynamic pressure. This versatile fabrication process enables tunable performance for diverse operational environments.