An awareness of the seriousness and symptoms of global warming is encouraging the development of technologies designed to reduce the emissions of CO2, a representative greenhouse gas, which contributes to global warming. The reduction of CO2 emissions has become a major environmental concern, and various methods such as absorption, adsorption, and membrane separation have been employed in CO2 capture. In recent times, technology designed to capture CO2 by adsorption has received considerable attention due to its low energy consumption and easy regenerability. In this study, 3-aminopropyl-triethoxysilane modified graphite oxide (Gr-APTS) was synthesized via the functionalization of graphite oxide (GO) with amine molecules for the development of a new CO2 adsorbent. GO was prepared to hold extensive oxygen-containing functionalities through oxidizing graphite with highly concentrated acid. Then, the amine molecules were grafted onto the surface of the GO, which provided an enhancement of the CO2 affinity and increased the CO2 adsorption uptake at a temperature of 30 degrees C and a pressure of similar to 1 atm. Gr-APTS also showed a highly stable CO2 adsorption uptake in the adsorption/desorption cycles.