| Popis: |
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 (α-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 °C, 200 °C, and 250 °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 °C formed a final product consisting of goethite (α-FeOOH) and hematite particles in contrast to the those precipitated at 200 °C and 250 °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 °C but did not affect the transformation at 250 °C. |
