Influence of cobalt/manganese ratio on structural, magnetic, and antibacterial properties of spinel ferrite nanocomposites synthesized by novel henna-green/microwave-assisted hydrothermal method
Year: 2026
Type: article
Abstract: Spinel ferrite nanoparticles offer a unique combination of magnetic functionality and antimicrobial activity, motivating the development of sustainable synthesis routes and compositional tuning strategies for biomedical and environmental applications. This study aimed to elucidate how the cobalt/manganese ratio modulates the structural, magnetic, and antibacterial properties of Co x Mn (1−x) Fe 2 O 4 nanocomposites prepared via a novel henna-green/microwave-assisted hydrothermal method that leverages henna extract as an eco-friendly capping agent. Thermal analysis of Co 0.5 Mn 0.5 Fe 2 O 4 showed multistep mass losses associated with dehydration and precursor/henna decomposition. FTIR bands near ~ 520 and ~ 420 cm − 1 confirmed spinel M–O vibrations in tetrahedral and octahedral sites with composition-dependent shifts. XRD verified a cubic spinel phase of MnFe 2 O 4 with minor phases of α-Fe 2 O 3 and Mn 2 O 3 while Co incorporation promoted notably pure CoFe 2 O 4 ; crystallite sizes ranged from 37.5 nm (CoFe 2 O 4 ) to 43.6 nm (MnFe 2 O 4 ). SEM revealed Co/Mn-dependent morphologies (flower-like plates, elongated plates, segmented cubes, round disks, polygonal structures). XPS confirmed mixed valence states (Co 2+ /Co 3+ , Mn 2+ /Mn 3+ , Fe 2+ /Fe 3+ ) and lattice/defect oxygen components. All compositions were ferromagnetic, with the highest coercivity for Mn 0.25 Co 0.75 Fe 2 O 4 (772 G) and composition-driven increases in magnetization (M s up to 92 emu/g; M r up to 22 emu/g). Antimicrobial testing showed strongest overall activity against S. aureus, with maximal reduction for CoFe 2 O 4 (94%); E. coli reduction peaked at 54% (CoFe 2 O 4 ), while C. albicans reduction was highest for MnFe 2 O 4 (37%). Collectively, the henna-assisted microwave-hydrothermal route enables composition-controlled Co–Mn ferrite nanocomposites whose phase assemblage, morphology, magnetic hardness, and antimicrobial performance can be tailored by the Co/Mn ratio, supporting application-specific design of multifunctional ferrite materials.
Source: Scientific Reports
Authors: Basmah Ghalib, Manal Hessien
Institution: King Faisal University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,690
Funder: King Faisal University
Award: G6467830277
OpenAlex ID: W7155016433