Synthesis, stability tests and irradiation evaluation of hollow MoS₂ nanomaterials

Abstract

Technetium-99m (^99mTc) is a critical isotope in nuclear medicine, used for diagnostic imaging. It is conventionally produced in a aluminum oxide ⁹⁹Mo/^99mTc generator that runs on molybdenum-99 (⁹⁹Mo) produced by fission of uranium-235. This fission-based production method faces several challenges. To address these challenges, alternative production pathways are being explored. Neutron irradiation of enriched ⁹⁸Mo nanomaterials and proton bombardement of enriched ¹⁰⁰Mo nanomaterials are two of the possible options. Within this research, the pathway of ⁹⁸Mo neutron capture will be the focus.
Developing a novel circular low specific activity 99Mo/99mTc generator that can run on these materials requires research to be done into the potential materials. The materials must meet two qualifying conditions: they should have a high surface-to-volume ratio, and show high radionuclide extraction potentials. This is an exploratory study to determine if molybdenum disulfides can be synthesized to meet those conditions.
Multiple synthesis methods of MoS₂ nanostructures were explored, and insights were given on their morphological and compositional characteristics. Of the six synthesized materials, four were MoS₂ nanospheres, one was MoS₂ microcubes and one was unable to be characterized
due to unsuccessful separation of the product. Two of the products were further evaluated on their stability and surface area. Stability tests in milliQ were done under two conditions: five consecutive cycle washes and five time-based washing cycles. Both materials exhibited lower Mo breakthrough during the consecutive washes than during the time-based wash cycles. The most compelling results were the downward trend that the Mo breakthrough data shows for the consecutive washes and the high breakthrough percentage in the 24 h soak for one of the samples (namely, 1.2 ± 0.28%) . Furthermore, the same two materials were tested on irradiation performance. Radionuclide extractions were made in milliQ, and extraction yields were calculated for ⁹⁹Mo.