Effect of glycine on one-step solution combustion synthesis of magnetite nanoparticles

Abstract Magnetite (Fe 3 O 4 ) nanoparticles have been readily prepared via a one-step solution combustion synthesis (SCS) method by designing a simple airless device: a beaker with perforated rubber plug could not only separate the outside air but also release the gases generated during the combustion reaction, which could ensure an air free condition in the SCS process. The whole process did not involve any toxic or unavailable reagents, and could be finished in a few minutes by its self-generated energy derived from the redox reaction between glycine (fuel) and ferric nitrate (oxidizer). Innovatively, the combustion reaction mechanism, morphology and microstructure, phase composition and magnetic properties of SCS products in relation to the glycine have been systematically investigated. The results revealed that with the increasing molar ratio (ϕ) of glycine to ferric nitrate, the combustion mode varied from self-propagating combustion to smouldering combustion and the average grain size of SCS products increased in nanometer scale. On the contrary, the iron oxidation state of SCS products decreased with the increase of ϕ value, and the oxide phase changed from α-Fe 2 O 3 to Fe 3 O 4 and then to FeO sequentially. It was noteworthy that when ϕ = 0.7, we could easily obtain pure phase Fe 3 O 4 nanoparticles with the highest saturation magnetization of 89.17 emu g −1 and small average grain size of 57.3 nm, which would have great potential for various applications, such as magnetic drug delivery, magnetic data storage and novel ferrofluids.