Hydrothermal synthesis and characterization of an akaganeite-type iron oxide octahedral molecular sieves (FeOx-OMS) by direct dissolution and transformation of layered precursor to 2x2 tunnel structure

• Main Author: Alfornon, Pamela V.
• Format: text
• Language: English
• Published: Animo Repository 2001
• Subjects: Iron oxides > Magnetic properties; Chemistry; Physical and theoretical; Chemical structure
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/2681
• Institution: De La Salle University

Iron oxide octahedral molecular sieve with 2x2 tunnel, designated as FeOx-OMS (2x2) was successfully synthesized through hydrothermal method. FeOx-OMS (2x2) has high degree of purity and higher thermal stability than those of previously reported akaganeite-type materials. The XRD pattern shows peaks that are characteristic of pure akaganeite-system. Based on its TGA (thermogravimetric analyses) profile, its thermal stability is reported at 255 degrees Centigrade and at 402 degrees Centigrade, a new phase is formed which is hematite-magnetite based on its XRD pattern. The SEM result shows a needle-like morphology that is a characteristic feature of a tunnel structure.Another successful route in producing akaganeite-type material is via transformation of a layered, lepidocrocite-type material precursor referred to as 1-FeOx-L2. Although this tunnel material has a lower thermal stability which is at 195 degrees Centigrade, its XRD pattern shows a relatively pure akaganeite-type material. It has also a needle-like morphology based on its scanning electron microscopy (SEM).