Solid-State Thermal Reaction of a Molecular Material and Solventless Synthesis of Iron Oxide

Abstract

Solid-state thermal decomposition reaction of a molecular material $$\{\hbox {As}(\hbox {C}_{6}\hbox {H}_{5})_{4}[\hbox {Fe}^{\mathrm{II}}\hbox {Fe}^{\mathrm{III}} (\hbox {C}_{2}\hbox {O}_{4})_{3}]\}_{\mathrm{n}}$$ has been studied using non-isothermal thermogravimetry (TG) in an inert atmosphere. By analyzing the TG data collected at multiple heating rates in 300 K–1300 K range, the kinetic parameters (activation energy, most probable reaction mechanism function and frequency factor) are determined using different multi-heating rate analysis programs. Activation energy and the frequency factor are found to be strongly dependent on the extent of decomposition. The decomposed material has been characterized to be hematite using physical techniques (FT-IR and powder XRD). Particle morphology has been checked by TEM. A solid-state reaction pathway leading the molecular precursor to hematite has been proposed illustrating an example of solventless synthesis of iron oxides utilizing thermal decomposition as a technique using innocuous materials.