Metastable energetic nanocomposites of MOF-activated aluminum featured with multi-level energy releases.

• An energetic MOF was firstly in-situ synthesized on the Al surfaces (n-Al@EMOFs). • n-Al@EMOFs is featured by multi-level energy releases. • The total heat release of n-Al@EMOFs is as highly as 4142 J g−1. Development of the high energy storage with controlled way of releases is always desirable but challenging. Herein, a novel design of energy-storage system based on aluminum has been demonstrated with improved energy content. This group of hybrid materials uses energetic metal–organic frameworks (EMOFs) as the precursors of the metal oxides as the oxidizers in conventional nanothermites. These metastable nanocomposites of energetic MOF-activated Al (n-Al@EMOFs) are able to undergo self-sustainable combustion with multi-level energy releases. The resulted n-Al@EMOFs show unique two-step exothermic processes with a total heat release of as highly as 4142 J g−1, which is much higher than that of conventional Al/CuO system. In addition, the strategy could also help to reduce the high susceptibility of n-Al to surface oxidation and lower the ignition temperature of the composites (301.5 °C). [ABSTRACT FROM AUTHOR]