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.

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.

To improve the adsorption performance of carbon dioxide, which is considered the main culprit of greenhouse gases, the specific surface area and high pore volume of the adsorbing material should be considered. For a porous material, the performance of carbon dioxide adsorption is determined by the amine groups supporting capacity; the larger the pore volume, the greater the capacity to support the amine groups. In this study, a double-shell mesoporous hollow silica nanomaterial with excellent pore volume and therefore increased amine support capacity was synthesized. A core–shell structure capable of having a hollow shape was synthesized using polystyrene as a core material, and a double-shell mesoporous shape was synthesized by sequentially using two types of surfactants. The synthesized material was subjected to a sintering process of 600 degrees, and the N2 sorption analysis confirmed a specific surface area of 690 m2/g and a pore volume of 1.012 cm3/g. Thereafter, the amine compound was impregnated into the silica nanomaterial, and then, a carbon dioxide adsorption experiment was conducted, which confirmed that compared to the mesoporous hollow silica nanomaterial synthesized as a single shell, the adsorption performance was improved by about 1.36 times.