Synthesis and Characterization of Magnetically Modified Composites (TiNT/CNT/Fe₃O₄)

In this study, Titania nanotube (TiNT) had been modified by combining it with carbon nanotube (CNT) and magnetic material, Fe₃O₄, forming magnetically modified composite (TiNT/CNT/Fe₃O₄). Magnetic properties were added to the composite to overcome photocatalytic application problem for waste water treatment case, especially the catalyst recovery issue. Prior to the modifications, TiNT was synthesized from TiO₂ P25 using hydrothermal process at 130 °C for 6 h. TiNT and CNT were then combined using hetero agglomeration process in acid condition to obtain TiNT/CNT composite. Various amount of Fe₃O₄ nanoparticles were then composed on the surface of TiNT/CNT using ultrasonic assisted in-situ process, producing TiNT/CNT/Fe₃O₄ magnetic composites. The samples were analyzed with various characterizations: zeta potential, FT-IR, FE-SEM/EDX, XRD, and VSM. Experimental results show that TiNT/CNT/Fe₃O₄ composite with good crystallinity and morphology had been successfully synthesized. The optimal amount of Fe₃O₄ in TiNT/CNT/Fe₃O₄ magnetic composite was 0.3 times the amount of TiNT to minimize the photodissolution effect, while the composite was still categorized as superparamagnetic materials (with the saturation magnetization value of 21.1 emu/g and coercivity of 84.4 oe). The magnetic separation test also confirmed that prepared magnetic composites could be effectively separated from the test solution. (paper)