Rapid Microwave Method for Synthesis of Iron Oxide Particles under Specific Conditions

The advantages of microwave technology over conventionally conducted experiments are numerous. Some of them are reduction in reaction time, a higher degree of process control, repeatability, and work safety. Microwave synthesis routes require a complete description of the experimental details, instrumentation, and design program of a microwave oven used in the experiments. In this work, microwave-assisted hydrothermal synthesis of hematite (alpha-Fe2O3) particles from 0.1 M FeCl3 solution in highly alkaline media with heating in a microwave oven at continuous microwave emission of 800 W at 150 degrees C, 200 degrees C, and 250 degrees C for 20 min are presented. Also, the influence of the percentage of the addition of a cationic surfactant, cetyltrimethylammonium bromide (CTAB) on the composition, size, and shape of the final product was investigated. The samples precipitated at 150 degrees C formed a final product consisting of goethite (alpha-FeOOH) and hematite particles in contrast to the those precipitated at 200 degrees C and 250 degrees C where pure hematite phase was obtained. In these synthesis routes, the CTAB caused to slow down the rate of the goethite-to-hematite transformation process at temperatures at 200 degrees C but did not affect the transformation at 250 degrees C.

Automated summary

Microwave technology offers numerous advantages over traditional experiments, including reduced reaction time, improved process control, and higher level of repeatability. This study focuses on microwave-assisted hydrothermal synthesis of hematite particles and investigates the impact of cationic surfactant CTAB on the composition, size, and shape of the final product. The presence of CTAB was found to affect the transformation process of goethite to hematite at 200 degrees C but not at 250 degrees C.