Synthesis and Characterization of CoFe ₂ O ₄ –Mn ₃ O ₄ –TiO ₂ (TMC) Nanocomposite as an Efficient Adsorbent for Heavy Metal Removal

Toxic heavy metals such as lead, cadmium, chromium, and mercury pose serious environmental and health hazards due to their persistence and bioaccumulation in aquatic systems. In this study, a ternary metal oxide nanocomposite of CoFe2O4–Mn3O4–TiO2 (TMC) was synthesized by mixing individually prepared oxide precursors. The precursors were first synthesized separately via the coprecipitation method and subsequently mixed and thermally treated to obtain the final TMC nanocomposite. The synthesized nanocomposite was characterized by XRD, FTIR, TG-DSC, SEM–EDX, TEM, VSM, and BET analyses and evaluated for its effectiveness in heavy metal removal. The ternary metal oxide exhibited an average crystallite size of less than 100 nm. Magnetic characterization showed saturation magnetization (Ms) of 8.44 emu g–1, remanent magnetization (Mr) of 3.48 emu g–1, and coercivity (Hc) of 661.58 Oe, confirming its suitability for magnetic separation. With a BET surface area of 8.1 m2/g, it demonstrated remarkable heavy metal removal efficiencies following the order: Cr6+ (84%) > Pb2+ (81%) = Hg2+ (81%) > Cd2+ (72%) at a high metal concentration of 300 ppm, pH ∼6.5 and temp 26 °C, establishing it as a promising candidate for wastewater remediation applications.