Atmospheric Plasma Jet Oxidation of Solution Based Precursors for Enabling Material Discovery

Abstract

Paramount to the global action plan on climate change is the renewable energy technology that drives carbon neutrality goal, and vital in this pursuit is the addressing of material challenges currently facing this technology. To properly address this issue, a synthesis technique capable of accelerating the discovery of materials for various energy conversion and storage applications needs to be developed. Here we present a technique that allows rapid and controlled synthesis of mixed metal oxide particles using plasma oxidation of liquid droplets containing mixed metal precursors1. The conventional wet chemical methods for synthesis of multimetal oxide solid solutions often require time-consuming high pressure and temperature processes, and so the challenge is to develop rapid and scalable techniques with precise compositional control. The concept is demonstrated by synthesizing binary and ternary transition metal oxide solid solutions with control over entire composition range using metal precursor solution droplets oxidized using atmospheric oxygen plasma. The results show the selective formation of metastable spinel and the rocksalt solid solution phases with compositions over the entire range by tuning the metal precursor composition. The synthesized manganese doped nickel ferrite nanoparticles, NiMnzFe2−zO4 (0 ≤ z ≤ 1), exhibits considerable electrocatalytic activity toward oxygen evolution reaction, achieving an overpotential of 0.39 V at a benchmarking current density of 10 mA/cm2 for a low manganese content of z = 0.20.