Core-Shell Hetero-Framework derived Copper Azide Composites as Excellent Laser-Ignitable Primary Explosives

Laser initiation has attracted increasing interest owing to its extraordinary safety and high reliability. However, traditional metal complex-based laser-ignitable primary explosives are limited by high input laser energy and low detonation ability. In this study, an efficient laser-ignitable primary explosive-based copper azide is prepared by constructing core-shell hetero-framework Cu-MOF@COF as the precursor. The pyrolysis of Cu-MOF@COF hybrid material affords copper azide (CA) nanoparticle confined in a porous carbon shell, referred to CA@C Shell. The evenly coated porous carbon shell functions as light-to-heat conversion layer efficiently promoting the laser initiation process of inside CA. Consequently, CA@C Shell can be initiated at lower laser energy thresholds (0.80 mJ at 1064 nm). This value is significantly lower than typical laser ignitable metal complex tetraamine-cis-bis(5-nitro-2H-tetrazolato-N₂)cobalt(III)perchlorate (726 mJ at 808 nm). Moreover, the CA@C Shell successfully detonates the secondary explosives CL-20 by laser energy when it is assembled in a micro-detonator system. This study offers a unique method for constructing high performance laser-ignitable primary explosives for micro-detonator applications.