ZIF-8 and polyaniline modified coconut gel to fabricate composite aerogel for efficient removal of tetracycline

Abstract

To overcome the limitations of large-scale applications for MOFs in the powder form, herein, we proposed a strategy of in-situ growth ZIF-8 onto polyaniline (PANI) modified coconut hydrogel (CCH). Firstly, PANI played the role of metal chelated layers, which were coated on CCH by in-situ polymerization. Then, ZIF-8 nanocrystals were in-situ growth on the surface of the PANI coated CCH to synthesise the composite adsorbent ZIF-8/PANI/CCH. Finally, after vacuum freeze-dried, a white and well structured ZIF-8/PANI/CCA(ZIF-8/polyaniline/coconut aerogel) was obtained. The loading mass ratios of ZIF-8 on CCA and PANI/CCA were 11.3% and 37.5%, respectively, which indicates that PANI as interface layers can effectively promote the in-situ growth of ZIF-8. The obtained composite adsorbent (ZIF-8/PANI/CCA) was applied for the adsorption of tetracycline (TC)，and the removal efficiency reaches over 91.6%. This strategy may provide an effective and versatile pathway to increase MOF loading mass on natural polysaccharide aerogel and sequentially branch out their applications in pollutant treatment fields.