Pressure And Solvent Induced Low-temperature Synthesis Of Monodisperse Superparamagnetic Nanocrystals: The Case Of Fe_3o_4 In Alkanols

摘要

The synthesis of nanoparticles via the decomposition of organometallic compounds has been studied extensively, but the effect of pressure lias received little attention. Here we firstly focus on the pressure effect, and utilize it as well as the solvent and temperature effects to develop a "green" cheap low-temperature (140-200 ℃) strategy via the decomposition of iron oleate in alcohol (or other alkanols) using oleic acid as the protecting reagent. The obtained monodisperse Fe_3O_4 nanocrystals (NCs) exhibit satisfying superparamagnetism. The mechanism of the process has been investigated and it was shown both high pressure and alkanol as the solvent can facilitate the formation of magnetite NCs. Furthermore, the solvent used in the preparation can control the shape, size and dispersion of NCs. In addition, the effects of reactant concentration, reaction time, temperature, and the mol ratio of oleic acid on the Fe_3O_4 NCs have also been discussed.