3-Nitro-1,2,4-triazol-5-one (NTO): High Explosive Insensitive Energetic Material

5-Nitro-3H-1,2,4-triazol-3-one (NTO) also known as nitrotriazolone is a low sensitive and thermally stable high energetic material containing a heterocyclic ring. NTO can be used to substitute highly sensitive high energetic materials that are thermally and photochemically less stable. This review provides a survey of various routes utilized for the synthesis of NTO, changes in its morphology by varying solvent systems, characterization, decomposition mechanisms, and use of metal oxides and other catalysts to enhance or diminish the thermal decomposition temperature of NTO. The review covers research on the synthesis, thermal decomposition mechanism, and catalytic effect of NTO additives from past four decades (1987–2021).