MnFe₂O₄/activated carbon composite: synthesis, molybdate adsorption, and ⁹⁹Mo/^99mTc radioisotope generator

Abstract Activated carbon (AC) derived from rice husks was synthesized via chemical activation and functionalized with manganese ferrite (MnF) nanocomposites through a one-step hydrothermal method to obtain MnF/AC. Molybdenum-99 ( 99 Mo) was produced at the Dalat Nuclear Research Reactor (Vietnam) via neutron irradiation. The synthesized materials were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, vibrating-sample magnetometry (VSM), nitrogen (N 2 ) adsorption/desorption isotherms, and energy-dispersive x-ray spectroscopy (EDX) with elemental mapping. Batch adsorption studies revealed a high 99 Mo(VI) uptake capacity of 333.23 mg·g −1 (Langmuir model), outperforming values reported in the literature. Adsorption followed pseudo-second-order kinetics, and thermodynamic parameters (ΔG°, ΔH°, ΔS°) confirmed a spontaneous process between 298–323 K. A 99 Mo/ 99m Tc (Technetium) generator was then successfully assembled using the MnF/AC-packed column. Elution with 5 ml of 0.9% NaCl at room temperature produced Na 99m TcO 4 with radiochemical purity near 100% and radionuclidic purity exceeding 99.6%, suitable for nuclear medicine applications.