Tuning the optical absorption and band gab of hydrogel methylcellulose loaded using hybrid Fe₃O₄@GO nanomaterials for optoelectronic and antibacterial activity

Hydrogel polymer nanocomposites are exciting materials with specific structural characteristics that absorb and maintain a large amount of biological fluid or water. This investigation focused on comparing reinforced methylcellulose (MC) polymer with individual synthesis of graphene oxide (GO) nanosheets or iron oxide (Fe₃O₄) nanoparticles or combined between them as hybrid nanomaterials. An advanced solution-acoustic-sonication procedure was applied with several characteristics to examine the hydrogel-nanocomposites. Remarkable strong physical interfacial interaction between the nanomaterials with MC resulted in shifting in infrared Fourier transform spectroscopy spectra without effect on the MC semicrystalline behavior. Delicate homogeneous, rough surfaces and nanoclusters were revealed using optical and field emission electron microscopy. The absorption of electron transition at 200 nm was improved by up to 21% after incorporating hybrid nanomaterials. The optical energy gap notably enhanced the semiconductor area from 4.79 to 4.0 eV for the allowed indirect transitions and 4.05–3.05 eV for forbidden indirect transitions. GO@Fe₃O₄ hybrid nanomaterials revealed an interesting inhibition zone of the antibiotic, remarkably improving from 6 mm up to 26 and 25 mm for Staphylococcus aureus and Escherichia coli, respectively, mm compared to reinforced with one nanocomposite. These results of a combination of magnetic, electrical, and surface properties make them ideal for various applications ranging from optoelectronic devices and environmental remediation to advanced biomedical technologies.