Controlled fabrication of the biomass cellulose aerogel@ZIF-8 nanocomposite as efficient and recyclable adsorbents for methylene blue removal

Design and fabrication of outstanding adsorbents for treating organic pollutants in wastewater following green chemistry principles remain huge challenging. In this paper, a biomass cellulose aerogel@ZIF-8 (CA@ZIF-8) based on bamboo leaves cellulose aerogel (CA) was controllable synthesized and used for the removal of methylene blue (MB) from aqueous solution. CA was prepared from bamboo leaves by NaOH/ urea low temperature dissolution method and freeze-drying method, and then ZIF-8 was grown in situ on its surface, successfully preparing CA@ZIF-8 composite with three-dimensional porous structure. The tests of X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to characterize the structures of materials, and the related results showed that arsenic was successfully adsorbed by the prepared CA@ZIF-8. The influences of pH (2-12), contact time (5-180 min), temperature (298 K, 308 K, 318 K) and other factors on MB adsorption quantity were studied in the adsorption experiments, and the maximum adsorption capacity was about 90.18 mg/g at 298 K. The adsorption thermodynamics showed that the adsorption process of CA@ZIF-8 to MB was spontaneous and decreased with the increase of temperature. The possible adsorption mechanism was also suggested. The CA@ZIF-8 exhibited good reusability that the removal of MB remained above 77.25 % after 5 cycles. The above results show that CA@ZIF-8 is a economically and proficient suitable material for removing MB from wastewater.