Photocatalytic oxidative-coupling of 5-amino-1H-tetrazole for the synthesis of 5,5′-azotetrazolate energetic salts at mild conditions

The conventional approach of 5-amino-1H-tetrazole (5AT) oxidative-coupling into 5,5'-azotetrazolate salts are confronted with several issues, including high energy consumption, insufficient security and inconvenient purification. A green photocatalytic method was demonstrated for the first time to achieve the selective oxidative-coupling of 5AT into 5,5'-azotetrazolate at mild conditions using g-C3N4. The oxidative-coupling of 5AT into 5,5'-azotetrazolate was mainly initiated by the photogenerated holes of g-C3N4, but center dot O-2(-) and center dot OH played important role in the activation of 5AT through capturing single hydrogen from the its amino. Under natural solar irradiation, the scaling-up photocatalytic synthesis of 5,5'-azotetrazolate energetic salt can be conveniently conducted.