Novel mesoporous iron oxide synthesized from naturally occurring magnetic sand: A potential and promising catalyst for chemical processes

Abstract

This paper presents the synthesis of iron oxide from natural magnetic sand that was obtained from Michika, Adamawa State, Nigeria. Characterization of the raw magnetic sand and the synthesized iron oxide was performed to investigate the effect of the synthesis method on functional groups, morphology, composition, crystallinity, acidity and surface area/pore distribution using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy – energy dispersive X-ray (SEM – EDX), X-ray fluorescence (XRF), X-ray diffraction (XRD), BET and pyridine FTIR, respectively. The XRF analysis of the two samples revealed a significant variation in oxide composition. The raw magnetic sand had an iron oxide content of 64.69 wt%, which increased to 85.20 wt% after synthesis. Furthermore, the SEM-EDX analysis indicated a decrease in average particle size from 114.6 and 36.8 µm for the respective samples. The XRD patterns revealed that the crystallinity increased after synthesis. FTIR showed the associations of functional groups present in the sample. The wavebands in the range 550 – 630 cm−1, which correspond to the Fe – O bond, improved clearly in the synthesized iron oxide sample, particularly at 582 cm−1. The pyridine FTIR depicts that the overall acidic site is higher in the synthesized sample. The N2 adsorption–desorption procedure shows an increased BET surface area from 9.394 m2/g (raw) to 24.851 m2/g (synthesized). Overall, the results showed that the synthesized mesoporous iron oxide exhibits properties similar to materials that have a high potential for application as catalysts in chemical processes.