One-Step Fabrication of High-Performance Energetic Metal-Organic Framework [Cu(atrz)₃[NO₃]₂]_n Films and its Tunable Crystal Structure

Nanoenergetics-on-a-chip (NOC) have been widely used with excellent performance. Nevertheless, the development of simple, convenient, low cost, and environmentally friendly strategies for preparation of energetic metal-organic framework (E-MOF) NOC films remains a challenge. In this work, we present a one-step solvothermal method to deposit three-dimensional (3-D) E-MOF films, [MOF_film(Cu); [Cu(atrz)₃(NO₃)₂]_n (atrz=4,4’-azo-1,2,4-triazole)] on oxidized copper foil. Physicochemical properties, including morphologies, decomposition temperature, sensitivity, laser ignition characteristics, and flame height of the MOF_film(Cu) films were analysed. With thermal stability up to 243 °C, the resulting MOF_film(Cu) films exhibit low sensitivity (Impact sensitivity (IS): 16 J; Friction sensitivity (FS): 112 N, and Electrostatic sensitivity (ESD): 24.75 J), combined with laser ignition capability. After laser excitement, MOF_film(Cu) films can act as an ignition material owing to a remarkable flame height (8 mm) and a violent explosion process (180 μs). More importantly, the energetic properties for MOF_film(Cu) films are conveniently tunable via a simple anion exchange strategy, and two new energetic MOF films, MOF_film(Cu) ⋅ SO₄ and MOF_film(Cu) ⋅ BF₄, have been prepared. This work provides a simple, safe, convenient, and lower cost strategy for fabricating energetic MOF films that are applicable in NOC technologies, and opens a new field for the application of anion exchange strategy.