Facile synthesis of iron oxides-silica by direct combustion of Mohr’s salt and oil palm leaves powder

Abstract

Iron oxide-silica is synthesized easily by direct decomposition at high temperature (500 °C for 5 h) of oil palm leaf powders in the presence of Mohr's salts under solid-solid state reaction. After the reaction mixture was cooled, a red powder was obtained and subjected to morphology, elemental, functional group and phase analysis using several instruments. The current product contains a mixture of metal-oxides, Fe2O3 and Fe3O4, as a result of iron oxidation, as well as amorphous silica derived from the decomposition of oil palm leaves (OPL), according to X-ray diffraction (XRD) analysis. Scanning Electron microscopy (SEM) shows that current techniques produce irregular particle shape products. Furthermore, the main elements which appear in the sample are silicon and iron along with other minor elements, as demonstrated by Energy-Dispersive X-Ray (EDX) analysis. The sample was also analyzed using Fourier Transform Infra-Red (FTIR) and the results showed that the current mix of metal-oxides gave specific peaks at 1112 cm−1 (Si-O-Si stretching vibration overlapped with Fe-O-Si stretching vibration), and 596 cm−1 (Fe-O stretching). Based on the results of this study, a new synthetic approach was obtained for the synthesis of mixed iron oxide-silica using sustainable precursors, oil palm leaves (OPL) with a simple combustion technique.