Synthesis of Ni nanopowders with cauliflower-like shapes and their catalytic property on the thermal decomposition of ammonium perchlorate

The study aims to synthesize Ni nanopowders by a facile method and understand the influence of Ni nanopowders on ammonium perchlorate (AP) thermal decomposition. Ni nanopowders with cauliflower-like shapes were prepared by simple reduction method at 80 & DEG;C with sodium hypophosphite as the reduction reagent. The morphologies, structure, composition and surface area of these nanopowders were analyzed by means of FESEM, XRD, EDS and BET. The results showed that the synthesized samples were evenly distributed and nanosized Ni with cauliflower-like shapes, with specific surface area of 9.7 m(2)/g. The catalytic property of Ni nanopowders on the thermal decomposition of AP was investigated by DSC tests. The results indicated that Ni nanopowders with cauliflower-like shapes had significant catalytic properties on AP thermal decomposition. Especially, Ni nanopowders with 8% addition in AP exhibited relatively higher catalytic activity, reducing decomposition temperature by about 144 & DEG;C and increasing apparent decomposition heat by 674 J/g. Kinetic analysis was carried out according to Kissinger method. The results showed that, after Ni nanopowders with cauliflower-like shapes were introduced, the activation energy of AP thermal decomposition decreased by 47% and the reaction rate constant grew by more than 115 times. In addition, the possible mechanism of AP thermal decomposition catalyzed by Ni nanopowders was briefly discussed. This study has certain theoretical and practical value for the synthesis of metal nanopowders and their catalytic application on the combustion behavior of AP-based solid propellants.