Facile synthesis strategy to create mesoporous magnetic iron oxides using pectin-based precursors

Abstract

Magnetic iron oxides are of great scientific and technological relevance. Therefore, herein, we report the research on developing methodologies for their sustainable and reproducible preparation. We discuss the synthesis of iron oxides involving citrus pectin as a source of energy (42 MJ kg-1) to promote the formation of the magnetic phases. The method involved two simple steps: gelation of the pectin (80 °C, 4 h) with iron nitrate nonahydrate [Fe(NO3)3.9H2O], and calcination (600 °C, 1 h). X-ray diffraction indicated the major formation of hematite (α-Fe2O3) and ferrite phases. Microscopy images show materials with an average size below 50 nm. Textural properties indicated pore sizes of 7-30 nm while magnetic measurements indicated the formation of soft and hard oxides (coercivity between 90 and 400 Oe) and high magnetization saturation (50 emu g-1).