One-step solution combustion synthesis of nanostructured transition metal antiperovskite nitride and alloy

Abstract

Multicomponent transition metal-based nanomaterials (MTMAs) are of interest to the materials science community because of their structure-tunable properties. However, it is challenging to support the phase stabilization and homogeneous distribution of the constituent elements within a single phase. Herein, we report the successful one-step combustion syntheses of a novel quaternary antiperovskite nitride, (Co0.33Cu0.33Ni0.33)4N, and a ternary CoCuNi alloy as examples of MTMAs. The synthesized nanomaterials have hollow spherical and sponge-like morphologies. We also share the results of a study of the parameters that influence the alloy and nitride phase formation and discuss possible mechanisms for the combustion synthesis of the MTMAs. It was established that the synthesis approach as well as adjusting the environment conditions created through the main synthesis parameters, including molar φ ratio, furnace temperature (Tfurn) and carrier gas flow rate, are the key characteristics responsible for the formation and stabilization of specific phase composition and morphology of the final product. The optimal parameters for the ternary CoCuNi alloy synthesis by sol–gel combustion were φ in the range of 1.25–1.5. The stoichiometric (Co0.33Cu0.33Ni0.33)4N phase stabilizes during a spray combustion synthesis with φ = 3, Tfurn = 900 °C and a flow rate of 4 L/min. The produced alloy possesses a high saturation magnetization of 74 emu/g, while the nitride retains only 11 emu/g. The study of the nitride phase’s hydrogenation reaction showed ∼96 % efficiency of NH3 evolution (3.797 mmol/g).