The escalating levels of carbon dioxide in flue gas and the resultant greenhouse effect have heightened the need for adsorbents with high CO2 sorption and separation capabilities. However, Traditional heated synthesis methods are energy-intensive and often involve toxic solvents, which are not viable for widespread industrial use. This study introduces a room-temperature, eco-friendly synthesis technique to produce UiO-66-(OH)2 with varying amounts of PVP (0/0.1/0.2 g), effectively adjusting the particle morphology. Results confirm that this method maintains robust CO2 adsorption and selectivity. Notably, the addition of 0.1 g of PVP led to a reduction in pore size and adsorption capacity of CO2, yet remarkably enhanced its CO2/N2 separation performance sixfold, outperforming traditional CO2 adsorbents. Dynamic breakthrough experiments further validated the effectiveness of UiO-66-(OH)2 in separating binary mixtures of CO2/N2 (v/v = 15/85).