Synthesis of Porous Carbon Spheres Embedded with Iron Oxide Nanoparticles for Sensing Devices and Methylene Blue Adsorption

Nanostructured materials containing iron oxide and carbon were synthesised using chitosan and iron chloride as chemical precursors in different proportions. These materials were applied as adsorbents and methanol sensors. The sample's characterisation used thermal analysis, temperature-programmed oxidation, infrared spectroscopy, X-ray diffraction, temperature-programmed reduction, Raman spectroscopy, and scanning electron microscopy. The characterisations confirmed the formation of a sp2 carbon matrix with iron embedded within it. The presence of functional groups on the carbon structure was also confirmed, and they were introduced through treatment with an acidic solution to produce the sensor. The sensor’s response to methanol was measured at different temperatures and concentrations. The results suggest good response and reproducibility of the sensor, which was synthesised using a straightforward method. The adsorption of methylene blue from an aqueous solution indicated a strong affinity between the adsorbent and the adsorbate, and the material's magnetic properties facilitate the extraction of the adsorbent.