A system and methods for additively manufacturing energetic particles such as polymer-free nanothermite aerogels are provided. An ink containing graphene oxide (GO), Al, and Bi.sub.2O.sub.3 nanoparticles in propylene carbonate is prepared. The method includes in-situ reduction of graphene oxide (GO), by ethylenediamine, during extrusion and printing of the ink onto a substrate with a simple printing system. The printed aerogels include reduced GO as a porous scaffold for the aerogel with Al and Bi.sub.2O.sub.3 clusters embedded therein. The linear burning rate of the printed aerogels reached a higher rate (10 m/s) that reported for typical polymer-assisted 3D printed nanothermite products. Also provided is a framework for optimizing a nanothermite fuel grain structure to match a desired combustion profile. The framework was used to model optimal fuel layer thicknesses, radii and bum rates for simple thrust, complex thrust and pressure matching cases.

The invention relates to an energy-releasing composite material comprising at least one nanoporous material and at least one inorganic oxidant, characterised in that said nanoporous material is a nanoporous carbon material.

The invention relates to an energy-releasing composite material comprising at least one nanoporous material and at least one inorganic oxidant, characterised in that said nanoporous material is a nanoporous carbon material.