This paper reports the synthesis of dual-amine-functionalized MCM-41 nanoparticles via a silane condensation approach for enhanced CO₂ capture applications. Mesoporous MCM-41 was prepared using a surfactant-templated sol–gel method and subsequently functionalized with a 1:1 mixture of Hydrosil 2775 and Hydrosil 2999 to introduce cooperative amine functionalities onto the silica surface. Formation of the target structure and successful surface modification were confirmed by Fourier-transform infrared spectroscopy, while Brunauer–Emmett–Teller analysis revealed a decrease in surface area and pore volume after functionalization, consistent with amine grafting within the mesoporous framework. Thermogravimetric analysis performed under pure CO₂ at 30 °C demonstrated an adsorption capacity of 1.7 wt%, calculated from total mass uptake during CO₂ exposure. The observed performance reflects the balance between amine loading and pore accessibility, which is inherent to grafted systems and provides insight into the design of dual-amine-functionalized mesoporous silica materials for post-combustion carbon capture applications.