Amine-functionalized mesoporous silica nanoparticles (MSNs) have emerged as promising materials for efficient CO₂ capture, offering high adsorption capacities, reusability, and environmental benefits. These materials exhibit significant potential in addressing global challenges related to sustainable energy transitions and carbon management. However, their widespread industrial application is hindered by challenges such as amine leaching, thermal degradation, and scalability. To enhance the stability and efficiency of amine-functionalized MSNs, strategies such as chemical grafting, polymer hybridization, and pore structure optimization have been explored. Additionally, efforts to improve thermal stability through the development of thermally stable amines, protective coatings, and stabilizing additives have shown promise in mitigating degradation during regeneration cycles. Future research must focus on the development of cost-effective, scalable, and environmentally sustainable synthesis methods, as well as strategies for enhancing adsorption efficiency and selectivity. Furthermore, the integration of CO₂ conversion technologies, such as catalytic transformation into value-added chemicals, represents a crucial advancement toward holistic carbon management. This review highlights the recent progress in amine-functionalized MSNs for CO₂ capture, discusses key challenges, and outlines future research directions to facilitate their large-scale industrial implementation.

Mesoporous fluorinated organosilicate films were synthesized from tetramethoxysilane and perfluoroalkylsilanes (RO)₃Si-R′ [R = Me, Et; R′ = (CH₂)₂CF₃, (CH₂)₂(CF₂)₅CF₃, or (CH₂)₂(CF₂)₇CF₃] under acidic conditions in the presence of cetyltrimethylammonium chloride (CTACl) by sol–gel spin-coating. Calcination at 350 °C allowed the removal of surfactants without destroying the other organic contents. X-Ray diffraction patterns of the fluorinated films with short perfluoroalkyl chains indicated that both hexagonal and cubic mesoporous fluorinated organosilicate films can be formed by varying the surfactant to silane mole ratio. On the other hand, the mesoporous fluorinated organosilicate films made from perfluoroalkylsilane with longer perfluoroalkyl chains, which acted as a surfactant, displayed a hexagonal mesostructure across a broad range of surfactant concentrations. Mesoporous fluorinated organosilicate films had higher hydrophobicity and lower refractive indices than mesoporous silica films.

Formaldehyde emitted from household products is classified as a hazardous substance that can adversely affect human health. Recently, various studies related to adsorption materials for reducing formaldehyde have been widely reported. In this study, mesoporous and mesoporous hollow silicas with amine functional groups introduced were utilized as adsorption materials for formaldehyde. Formaldehyde adsorption characteristics of mesoporous and mesoporous hollow silicas having well-developed pores were compared based on their synthesis methods—with or without a calcination process. Mesoporous hollow silica synthesized through a non-calcination process had the best formaldehyde adsorption characteristics, followed by mesoporous hollow silica synthesized through a calcination process and mesoporous silica. This is because a hollow structure has better adsorption properties than mesoporous silica due to large internal pores. The specific surface area of mesoporous hollow silica synthesized without a calcination process was also higher than that synthesized with a calcination process, leading to a better adsorption performance. This research suggests a facile synthetic method of mesoporous hollow silica and confirms its noticeable potential as a support for the adsorption of harmful gases.

This report describes strategies to increase the reactive surfaces of integrated gold nanoparticles (AuNPs) by employing two different types of host materials that do not possess strong electrostatic and/or covalent interactive forces. These composite particles are then utilized as highly reactive and recyclable quasi-homogeneous catalysts in a C-C bond forming reaction. The use of mesoporous TiO₂ and poly(N-isopropylacrylamide), PNIPAM, particles allows for the formation of relatively small and large guest AuNPs and provides the greatly improved stability of the resulting composite particles. As these AuNPs are physically incorporated into the mesoporous TiO₂ (i.e., supported AuNPs) and PNIPAM particles (i.e., encapsulated AuNPs), their surfaces are maximized to serve as highly reactive catalytic sites. Given their increased physicochemical properties (e.g., stability, dispersity, and surface area), these composite particles exhibit notably high catalytic activity, selectivity, and recyclability in the homocoupling of phenylboronic acid in water and EtOH. Although the small supported AuNPs display slightly faster reaction rates than the large encapsulated AuNPs, the apparent activation energies (E_a) of both composite particles are comparable, implying no obvious correlation with the size of guest AuNPs under the reaction conditions. Investigating the overall physical properties of various composite particles and their catalytic functions, including the reactivity, selectivity, and E_a, can lead to the development of highly practical quasi-homogeneous catalysts in green reaction conditions.

To adsorb and remove formaldehyde, which is a harmful volatile organic chemical (VOC) detected indoors, an alkylamine was introduced into the substrate as a formaldehyde adsorbent. In this study, Tetraethylenepentaamine (TEPA) was introduced into the mesoporous silica using the amine impregnation method. Since the impregnated alkylamine can block the pores of the silica substrate, the pore size and pore volume are very important factors for its use as a substrate for an adsorbent. Focusing on the substrate’s pore properties, Santa Barbara Amorphous-15 (SBA-15) was chosen as a conventional one-dimensional pore-structured mesoporous silica, and dendritic mesoporous silica (DMS) as a three-dimensional pore-structured mesoporous silica. To 1 g each of silica substrate DMS and SBA-15, 0, 0.5, 1.5, and 2.5 g of TEPA were introduced. A fixed concentration and amount of formaldehyde gas was flowed through the adsorbent and then the adsorbent was changed to the 2,4-Dinitrophenylhydrazine (2,4-DNPH) cartridge to adsorb the remaining formaldehyde. According to the methods recommended by the World Health Organization (WHO) and National Institute for Occupational Safety & Health (NIOSH), the formaldehyde captured by 2,4-DNPH was analyzed using high-performance liquid chromatography (HPLC). A comparison of DMS and SBA-15 in the amine impregnation method shows that not only surface area, but also large pore size and high pore volume, contribute to the formaldehyde adsorption ability.

Although mesoporous silica materials have been widely investigated for many applications, most silica materials are made by calcination processes. We successfully developed a convenient method to synthesize mesoporous materials at room temperature. Although the silica materials made by the two different methods, which are the calcination process and the room-temperature process, have similar specific surface areas, the silica materials produced with the room-temperature process have a significantly larger pore volume. This larger pore volume has the potential to attach to functional groups that can be applied to various industrial fields such as CO₂ adsorption. This mesoporous silica with a larger pore volume was analyzed by TEM, FT-IR, low angle X-ray diffraction, N₂-adsorption analysis, and CO₂ adsorption experiments in comparison with the mesoporous silica synthesized with the traditional calcination method.