Synthesis and Characterization of Ordered and Disordered Mesoporous Alumina as High-Performance Molybdenum-99 Adsorbents

Abstract

Molybdenum-99 (⁹⁹Mo) is the parent radioisotope of technetium-99m (^99mTc),an essential medical radioisotope for diagnostic agents in nuclear medicine.In ⁹⁹Mo/^99mTc generator, a chromatography column system with ⁹⁹Mo adsorbent as afiller is usually used to produce ^99mTc in hospitals. However, it is still challenging to find high-performance adsorbentsfor Mo adsorption.We have synthesized both ordered and disordered mesoporous alumina and compared their performance as ⁹⁹Mo adsorbents. These materials were prepared via a soft-templated method using a triblock copolymer as the template, followed by air calcination at 400°C.The amount of nitric acid (HNO₃) and the drying time were adjusted systematically to synthesize the ordered mesoporous alumina. The obtained ordered and disordered mesoporous alumina were characterized by low-and wide-angle X-ray diffractions (XRD), nitrogen adsorption-desorption, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The ⁹⁹Mo adsorption capacities of these materials were evaluated by using the batch method. The experimental results show that the ordered mesoporous alumina hasa higher ⁹⁹Mo adsorption capacity of 72.06 mg(Mo)g^-1 than the disordered mesoporous alumina (50.12 mg(Mo)g^-1). The results indicate the excellent potential of ordered mesoporous alumina as an adsorbent for the ⁹⁹Mo/^99mTc generator column.