Sustainable Electrosynthesis of Porous CuN₃ Films for Functional Energetic Chips

A porous CuN₃ film has been facilely synthesized by a sustainable electroassisted azidation methodology using the template of porous Cu as a precursor. Such porous CuN₃ films show excellent performances of both superior energy release and tremendous brisance, which can be tuned by changes of the current density and azidation time. Energy release reaches a maximum of 1200 J·g^–1 at a current density of 3.0 mA·cm^–2 with a reaction time of 450 s. Meanwhile, the conversion ratio of Cu can reach ca. 31% with ca. 43 wt % of CuN₃ in the prepared CuN₃ film. In addition, the growth mechanism of the CuN₃ film is justified by not only experimental observations but also density functional theory calculations. Compared with the common gas–solid azidation method, this electrosynthesis strategy can lead to great reduction in the reaction time (from >12 h to <10 min) even without the use of dangerous HN₃ gas. Moreover, the preparation method here is fully compatible with microelectromechanical system (MEMS) technology, which is of great significance in promising applications for functional energetic chips.