Facile surfactant-free synthesis of monodisperse Ni particles via a simple solvothermal method and their superior catalytic effect on thermal decomposition of ammonium perchlorate

Successful synthesis of monodisperse nickel particles with narrow particle size distributions is reported for the first time via a simple solvothermal method with ultrasonic treatment using no surfactants. The Ni products are characterized by X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy. The as-synthesized monodisperse Ni particles show a spherical morphology with the mean particle size of 46.2, 60.1 and 113.7 nm for the reaction time of 0.5, 1 and 3 h, respectively at a low temperature of 100 degrees C. The catalytic effect is investigated for the Ni particles on the thermal decomposition of ammonium perchlorate (AP) using differential thermal analysis and thermogravimetry. For the purpose of comparison, as-prepared and commercial non-monodisperse Ni particles are used for examining the catalytic effect. The monodisperse Ni particles show a superior catalytic effect over the non-monodisperse Ni counterparts with a similar mean particle size. The surface areas of Ni particles are measured by Brunauer-Emmett-Teller (BET) technique. A theoretical consideration is also presented for analysis of the surface areas of monodisperse and non-monodisperse particles. Both the BET and theoretical results show that the surface area of monodisperse particles is higher than that of non-monodisperse counterparts. Consequently, the catalytic effect of Ni particles on thermal decomposition of AP is explained in terms of the surface areas.