中空碳纳米球与UiO-66复合材料的制备及其VOCs吸附性能OA

Volatile organic compounds(VOCs)significantly threaten both environmental sustainability and public health.However,it remains challenging to combine high capacity and stability in most existing adsorbents.In this work,hollow carbon nanospheres(HCNS)were synthesized under alkaline conditions using tetrapropyl orthosilicate as the silicon source,followed by modulation of their surface hydroxyl content through variations in alkali concentration or temperature to yield a series of HCNS-x.These HCNS-x were then composited with UiO-66,which possesses a high specific surface area and excellent thermal stability,to prepare HCNS-x/UiO-66 composites.Their surface properties and structures were investigated through various characterization techniques.The results indicated that HCNS-2,activated with 3 mol/L NaOH at 60℃,exhibited the highest surface hydroxyl content.Furthermore,its corresponding composite,HCNS-2/UiO-66,demonstrated the most optimal pore structure parameters(a specific surface area as high as 3694 m2·g-1,a total pore volume of 2.53 cm3·g-1,and an average pore size of 6.9 nm).Static toluene adsorption tests revealed that the toluene adsorption capacity of HCNS-2/UiO-66 was 2.305 g·g-1,which was 10.5 times that of pure UiO-66(0.220 g·g-1)and 1.6 times that of pristine HCNS(1.436 g·g-1).Dynamic toluene adsorption breakthrough curve analysis confirmed that HCNS-2/UiO-66 possessed the most excellent toluene adsorption performance with an equilibrium adsorption capacity of 2.140 g·g-1,which was attributed to its large specific surface area and optimized pore structure.Additionally,cycling tests demonstrated that HCNS-2/UiO-66 maintained stable performance over multiple dynamic adsorption-desorption cycles,demonstrating that its saturated adsorption capacity consistently remained around 2.15 g·g-1.This study constructed a VOCs adsorbent with high adsorption capacity and stability by modifying the HCNS surface to optimize its interfacial integration with UiO-66.