Aerosol growth and photothermal ignition of multilayer graphene-encapsulated nickel nanoparticles

Abstract

In this report, we propose an easy and viable fabrication method for growing multilayer graphene (MLG)-encapsulated nickel nanoparticles (Ni NPs) via a one-step continuous aerosol process comprising combined spray pyrolysis (SP) and thermal chemical vapor deposition (CVD). A bimodal size distribution was observed for the Ni NPs owing to droplet-to-particle and gas-to-particle conversions undergone in the SP at ~1000 °C. The number of graphene layers grown on the surface of Ni NPs in the thermal CVD was controlled by varying the reaction temperature of 300–700 °C, which perturbed the solubility and diffusion rates of carbon in Ni NPs. Finally, we demonstrated that the MLG-encapsulated Ni NP-added nanoenergetic materials were stably ignited by flash irradiation in a short ignition delay time (~267 μs) with fast burn rate (~200 m·s−1). This suggests that the MLG-encapsulated Ni NPs could play an important role as potential optical igniters for practical thermal engineering applications.