The primary goal of this study is to develop an environmentally friendly carbon-adsorptive film using polyvinyl alcohol (PVA), a nontoxic and eco-friendly material, as the base for the polymer gas adsorption film. By employing tetraethylenepentamine (TEPA) as a functionalizing agent, the PVA polymer film is immersed in a TEPA solution to introduce functional groups capable of adsorbing carbon dioxide (CO2) onto its surface. Fourier-transform infrared spectroscopy is used to analyze whether the TEPA successfully binds to the PVA film and to confirm the CO2 adsorption capability of the polymer gas adsorption film. The polymer gas adsorption film is placed in a CO2 chamber, and the changes in film resistance over different adsorption times are recorded. It is observed that for the first 30 min of adsorption, the relationship between adsorption time and resistance change is described by the equation y = −0.038x + 4.02, whereas after 30 min, the relationship follows y = −0.0023x + 2.52. The results show that CO2 adsorption reduces the resistance of the polymer gas adsorption film, with the most significant rate of decrease occurring within the first 30 min.