© 2021 by the authors. Licensee MDPI, Basel, SwitzerlandCueto Díaz, Eduardo J.Valles González, M. P.Torquemada, M. C.Gálvez Martínez, SantosSuárez García, FabiánCastro Muñiz, AlbertoMateo Martí, Eva2022-12-152022-12-152021-10-10Nanomaterials 11(11): 2893 (2021)2079-4991https://doi.org/10.3390/nano11112893http://hdl.handle.net/20.500.12666/818In this work, we have described the characterization of hybrid silica nanoparticles of 50 nm size, showing outstanding size homogeneity, a large surface area, and remarkable CO2 sorption/desorption capabilities. A wide battery of techniques was conducted ranging from spectroscopies such as: UV-Vis and IR, to microscopies (SEM, AFM) and CO2 sorption/desorption isotherms, thus with the purpose of the full characterization of the material. The bare SiO2 (50 nm) nanoparticles modified with 3-aminopropyl (triethoxysilane), APTES@SiO2 (50 nm), show a remarkable CO2 sequestration enhancement compared to the pristine material (0.57 vs. 0.80 mmol/g respectively at 50 °C). Furthermore, when comparing them to their 200 nm size counterparts (SiO2 (200 nm) and APTES@SiO2 (200 nm)), there is a marked CO2 capture increment as a consequence of their significantly larger micropore volume (0.25 cm3/g). Additionally, ideal absorbed solution theory (IAST) was conducted to determine the CO2/N2 selectivity at 25 and 50 °C of the four materials of study, which turned out to be >70, being in the range of performance of the most efficient microporous materials reported to date, even surpassing those based on silica.engAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttps://creativecommons.org/licenses/by-nc-nd/4.0/CO2/N2 selectivityCO2 adsorptionfunctional silica nanoparticlessurface spectroscopieshybrid nanomaterialsinfo:eu-repo/semantics/article10.3390/nano11112893info:eu-repo/semantics/openAccess34835658