FeCO₃ as a novel precursor for controllable synthesis of monodisperse iron oxide nanoparticles via solution thermal decomposition

Thermal decomposition in solution is the most effective approach for achieving highly monodisperse iron oxide nanoparticles (IONPs). However, a simple, economical, and environment-friendly iron precursor with high iron content remains in great demand. Although siderite (FeCO₃) has been reported to produce iron oxide particles via calcination, it is difficult to control the shapes of the obtained particles compared to those obtained by solution methods. Herein, FeCO₃ was employed as a precursor in solution thermal decomposition to prepare monodisperse IONPs and investigated the influence of reaction conditions on the particle size, including the concentration of oleic acid, concentration of the precursor, and the reaction temperature. The seed-mediated growth method with FeCO₃ as a precursor was also studied to extend the scope of particle size. The experimental results demonstrate that high-quality IONPs can be synthesized in solution via FeCO₃ thermal decomposition. The particle diameter was tuned between 3 and 20 nm by varying the reaction conditions, and by seed-mediated growth. FeCO₃ is thus a readily available, economical, environment-friendly precursor with high iron content, which is a novel candidate for the synthesis of IONPs.