Synthesis of Fe3O4 polyhedra by hydrothermal method: using l-arginine as precipitator

Unusual polyhedral structures of cubic Fe3O4 were fabricated in high yield via a facile hydrothermal method in the presence of a surfactant cetyltrimethyammonium bromide (CTAB). Hexagonal, dodecahedral, truncated octahedral, and octahedral shapes can be prepared by changing the concentration of the CTAB in l-arginine solutions. In the solution-phase synthesis, both the l-arginine and CTAB were found to be the prime factors for the formation of the polyhedral structures. In addition, room-temperature vibrating sample magnetometer (VSM) testing results indicated that the magnetite synthesized without the addition of CTAB had the highest Ms value and the lowest Hc value. This synthesis method is also suitable for the preparation of other ferrites with spinel structure.