High-performance energetic materials with rapid ignition, efficient heat release, and enhanced safety are urgently needed in propulsion and precision strike systems. Herein, a Mg 0.5 Al 0.5 B 2 -based core-shell-shell composite energetic material (denoted as MCAF) is fabricated using CL-20, AP, and a fluoropolymer via a two-step coating process. The hierarchical architecture enables effective spatial separation of components, improved compatibility, and regulated combustion behavior. Thermal analysis revealed a dual-stage energy release with an activation energy of 429 kJ·mol −1 , about 32% lower than raw Mg 0.5 Al 0.5 B 2 . Oxygen bomb calorimetry showed a combustion heat of 18.6 MJ·kg −1 , reaching 93.5% of its theoretical value and improving by 21% over the physical mixture. Pressure–time tests demonstrated a peak pressure of 7.9 kPa and a pressurization rate of 24.1 kPa·s −1 , which are 58% and 105% higher, respectively, than those of the mixture. Laser ignition experiments revealed a short delay of 13 ms (nearly 60% shorter), with stronger emission intensity and more complete combustion. In addition, MCAF exhibited low mechanical sensitivity (impact energy >20 J). Overall, these results demonstrate that the MCAF composite achieves faster ignition, more concentrated energy release, and higher combustion efficiency, while maintaining excellent safety. This work highlights a scalable strategy for designing next-generation energetic materials with high energy density and improved stability.
The green synthesis of energetic materials (EMs) is a challenging and critical research direction. Herein, we develop a Co 3 O 4 @ NiMoO 4 heterojunction photoanode for the photoelectrocatalytic (PEC) oxidation of 5-amino-1 H -tetrazole (5AT) to the 5,5′-azotetrazole disodium salt (SZT). The heterojunction, featuring NiMoO 4 nanosheets uniformly coated on Co 3 O 4 nanowire arrays, significantly enhances active site exposure and interfacial charge transfer. Mechanistic studies reveal that the heterostructure follows a direct Z-scheme charge transfer pathway, which not only promotes the separation of electron-hole pairs but also facilitates the efficient generation of ·OH radicals, thereby markedly enhancing the oxidation kinetics. Therefore, under PEC tests, the heterostructure achieves an oxidation potential of only 1.22 V vs. RHE at 10 mA·cm −2 in 0.2 M 5AT, which is 300 mV lower than that of pure Co 3 O 4 . Moreover, under the same PEC conditions, the electrode demonstrates excellent stability over 15 h of continuous operation. Successful SZT formation is confirmed by UV-vis and NMR spectroscopy. This work provides an efficient and sustainable strategy for EMs synthesis via heterojunction-engineered PEC catalysis, highlighting its potential for safe and energy-efficient organic synthesis.
In this work, the application of poly( p -phenylenediamine) (PpPD) as a potential propellant stabilizer is reported for the first time, and establish a solvent-free, continuous, and efficient mechanochemical synthesis method based on spiral gas-solid two-phase flow (S-GSF). Structural and morphological characterization results show that PpPD prepared by this method boasts advantages including high purity, high yield, mild reaction conditions, and easy scalability, with a space-time yield reaching 46.25 kg m −3 h −1 . In addition, the product is characterized by smaller particle size and more uniform distribution, which enhances the compatibility of the composites. After adding 3% (mass fraction) of PpPD to nitrocellulose, the nitrogen oxides produced by the decomposition, could be effectively reduced by 37.4%, and its stabilizing effect was better than that of DPA and C2. The thermal stability TGA loss was reduced by 52.5%. Electrostatic potential analysis and aromatic nitration theory indicated that the secondary amine sites of PpPD had high electron density and exhibited an obvious scavenging effect on NO x .
