Preparation and enhanced CO2 adsorption capacity of UiO-66/graphene oxide composites

New composites of UiO-66 and graphene oxide (GO) were synthesized and tested as CO 2 adsorbents at room temperature. The materials and the parent composite components were characterized using X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), nitrogen adsorption–desorption isotherm analysis, scanning electron microscopy (SEM), and FT-IR spectroscopy. The CO 2 isotherms on the UiO-66/GO composites and the UiO-66 were measured by a static volumetric method separately. Experiments of multiple adsorption/desorption cycles were conducted to estimate reversibility of CO 2 on the UiO-66/GO. The results showed that the BET surface area of the composites was higher than that of the parent UiO-66, and the adsorption capacities of CO 2 on the composites were greatly higher than that on the UiO-66 sample. The composite UiO-66/GO-5 exhibited the maximum CO 2 uptake of 3.37   mmol/g at 298   K and 1   bar, which increased by 48% in comparison with that of the UiO-66, and was much higher than those of the conventional activated carbons and the zeolites. The CO 2 adsorption capacity was dependent on the BET surface area and the micropore volume of the composites. Finally, the adsorption/desorption cycle experiment revealed that the adsorption performance of UiO-66/GO-5 was fairly stable, without noticeable degradation in the adsorption capacity of CO 2 after 6 cycles. Therefore, this kind of composites has a potential application on CO 2 capture technologies to mitigate global warming.