Polyaniline as interface layers promoting the in-situ growth of zeolite imidazole skeleton on regenerated cellulose aerogel for efficient removal of tetracycline

Abstract

Antibiotics as newly emerging organic pollutants are arousing more and more serious environmental issues. Meantime, metal–organic frameworks (MOFs) are considered as promising adsorbents to remove antibiotics. To overcome the limitations of large-scale applications for MOFs in the powder form, herein, we proposed a strategy of in-situ growth ZIF-67 onto polyaniline (PANI) modified regenerated cellulose aerogel (RCA). First, RCA was obtained by chemical cross-linking and physical cross-linking method. Then, PANI played the role of metal chelated layers, which were coated on RCA by in-situ polymerization. Finally, ZIF-67 nanocrystals were in-situ growth on the surface of the PANI coated regenerated cellulose aerogel to synthesise the composite adsorbent ZIF-67/PANI/RCA. The loading mass ratios of ZIF-67 on RCA and PANI/RCA were 25.39% and 42.38%, respectively, which indicates that PANI as interface layers can effectively promote the in-situ growth of ZIF-67 compared with pure RCA. The obtained composite adsorbent (ZIF-67/PANI/RCA) was applied for the adsorption of tetracycline (TC) with high adsorption capacity (409.55 mg·g−1) and good recycling ability. After six cycles of adsorption–desorption, the removal efficiency toward TC was still over 94%. This strategy may provide an effective and versatile pathway to increase MOF loading mass on aerogel and sequentially branch out their applications in pollutant treatment fields.