Unlocking F-O synergistic effects in TiOF₂-based nano-thermites: Enhanced combustion performance and reaction kinetics

Developing efficient oxidizers is critical for advancing nano thermites. Titanium oxyfluoride (TiOF₂) with oxygen/fluorine dual-active centers is innovatively employed as an oxidizer in Al/TiOF₂ composites prepared via physical mixing. Structural and morphology characterization confirms uniform interfacial contact while preserving component stability. The system demonstrates exceptional reactivity: onset and peak reaction temperatures (409.4°C, 470.0°C) are reduced by 139.1°C and 130.7°C, respectively, versus Al/TiO₂, with activation energy lowered to 84.35 kJ·mol⁻¹. Synergistic F–O interactions impair reaction barriers, yielding 3692.2J·g⁻¹ heat release (120 % increase over Al/TiO₂). Combustion tests reveal vigorous ignition under low energy input, rapid flame propagation, and two-stage spark ejection. This work reveals the activation mechanism of oxyfluoride as an oxidizer for thermites: fluorine enhances the reaction kinetics through an interfacial modification effect, while oxygen guarantees the energy density of the system. The synergy of the two elements realizes the optimization and regulation of combustion performance.