Tuning magnetic recoverability and UV optical properties of Fe3O4/TiO2 nanocomposites through controlled TTIP loading: A trade-off study

This study investigated the structural, magnetic, and UV absorption properties of Fe 3 O 4 /TiO 2 nanocomposites. However, systematic studies correlating Fe 3 O 4 -to-TiO 2 molar ratios with their structural, morphological, magnetic, and optical properties remain limited. In this study, Fe 3 O 4 /TiO 2 nanocomposites with varying molar ratios (3:1, 1:1, 1:3, 1:5, and 1:7) were successfully synthesized using a co-precipitation method. The crystal structure, functional groups, surface morphology, elemental distribution, grain size, magnetic properties, and optical properties were comprehensively characterized. X-ray diffraction patterns showed both cubic spinel Fe 3 O 4 and anatase TiO 2 phases with crystallite sizes of 7.65–9.99 nm for Fe 3 O 4 and 7.20–8.39 nm for TiO 2 . Fourier transform infrared analysis indicated Fe-O and Ti-O stretching vibrations, and shifts in the wavenumber suggested strong interfacial interactions between the Fe 3 O 4 and TiO 2 phases. The electron microscopy images showed that increasing the TiO 2 ratio to 1:7 inhibited the formation of nanorod-like structures and gave an average particle size of 9.79 ± 0.22 nm. The magnetic measurements revealed that the saturation magnetization decreased continuously from 60.05 emu/g (Fe 3 O 4 ) to 14.73 emu/g (1:7 ratio) as the non-magnetic TiO 2 content increased. The optical absorption measurements revealed a blue shift in the absorption edge from 370 nm to 315 nm with increasing TiO 2 ratio. The band gap energy showed a similar increasing trend from 2.85 eV to 3.13 eV. Among all the variations, the 1:7 ratio showed the strongest UV optical characteristic and smallest particle size, but with a low saturation magnetization (14.73 emu/g), which suggests a trade-off between optical performance and magnetic recovery capability.