Biomolecule‐Assisted Synthesis of Hierarchical Multilayered Boehmite and Alumina Nanosheets for Enhanced Molybdenum Adsorption

Abstract

The effective utilization of various biomolecules for creating a series of mesoporous boehmite (γ‐AlOOH) and gamma‐alumina (γ‐Al2O3) nanosheets with unique hierarchical multilayered structures is demonstrated. The nature and concentration of the biomolecules strongly influence the degree of the crystallinity, the morphology, and the textural properties of the resulting γ‐AlOOH and γ‐Al2O3 nanosheets, allowing for easy tuning. The hierarchical γ‐AlOOH and γ‐Al2O3 multilayered nanosheets synthesized by using biomolecules exhibit enhanced crystallinity, improved particle separation, and well‐defined multilayered structures compared to those obtained without biomolecules. More impressively, these γ‐AlOOH and γ‐Al2O3 nanosheets possess high surface areas up to 425 and 371 m2 g−1, respectively, due to their mesoporous nature and hierarchical multilayered structure. When employed for molybdenum adsorption toward medical radioisotope production, the hierarchical γ‐Al2O3 multilayered nanosheets exhibit Mo adsorption capacities of 33.1–40.8 mg g−1. The Mo adsorption performance of these materials is influenced by the synergistic combination of the crystallinity, the surface area, and the pore volume. It is expected that the proposed biomolecule‐assisted strategy may be expanded for the creation of other 3D mesoporous oxides in the future.

Development of Novel Alumina by Solid-State Reaction for 99Mo/99mTc Adsorbent Material

“…The plot of 1/[W((W(Po/P)-1)] and relative pressure can be seen in Figure 2, which is used for the surface area calculation. The calculated SBET was 237.65 m 2 /g, similar with most alumina SBET which is ranging from 200-450 m 2 /g (Chakravarty et al, 2013;Saptiama et al, 2017Saptiama et al, , 2019. Even though the surface area is an important parameter for the adsorption process, the other parameter, for instance, crystal phase and acidity, might also play an important role (Sulaiman et al, 2018).…”

“…Various synthesis method has been performed to produce many derivative alumina, for instance, mesoporous alumina (Saptiama et al, 2017), mesoporous ordered alumina, and doped alumina. Saptiama, et al had developed nanosheet alumina (Saptiama et al, 2019), nanospheres alumina and alumina embedded mesoporous silica which has adsorption capacity to molybdenum greater than conventional alumina. However, adsorption study using 99 Mo for these materials has not been performed and the synthesis route was quite sophisticated.…”

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

“…Molybdenum adsorption experiments have been conducted using MA-1 and MA-6 as representative samples via the batch method (Table 3) to examine their potential as adsorbents for 99 Mo/ 99m Tc generator columns. The Mo adsorption experiments were conducted at an optimum pH of 3 based on previous findings [4][5][6]. Ordered mesoporous alumina (MA-6) shows a higher Mo adsorption capacity of 72.06 mg (Mo) g -1 than disordered mesoporous alumina (MA-1) (50.12 mg (Mo) g -1 ), despite its slightly lower surface area (Table 2).…”

“…Microporous materials possess pore size less than 2 nm, while mesoporous materials exhibit pore size between 2 nm and 50 nm, and macroporous materials exhibit pore size greater than 50 nm [1]. Mesoporous materials have been used in a wide variety of applications, including catalysis [2], adsorption [3][4][5][6], drug delivery systems [7,8], gas sensors [9,10], energy storage [11,12], and radionuclides separation [13,14]. The ordered mesoporous material was prepared using a softtemplating method, where the templates were  Corresponding author.…”

Fabrication of γ-Al2O3 Nanoarrays on Aluminum Foam Assisted by Hydroxide for Monolith Catalysts

“…Metal substrates can be covered by a “washcoat” with in situ growth, resulting in greater adhesion between substrates and overlayer due to chemical linkages. Open-cell metal substrates, for example, have been proposed for the removal of gaseous pollutants, − water treatment, , reforming of methane, supercapacitors, fuel cells, thermal storage, and so on. Furthermore, the coefficient of thermal conductivity of metals such as Al (∼237 W m –1 K –1 ) is hundreds of times greater than that of cordierite, resulting in more uniform temperature distribution and improved heat efficiency when employed on a broad scale.…”