Cellulose-zeolitic imidazolate frameworks (CelloZIFs) for multifunctional environmental remediation: Adsorption and catalytic degradation

The crystal growth of zeolitic imidazolate frameworks (ZIFs) on biopolymers such as cellulose is a promising method for obtaining hybrid materials that combinenatural and synthetic materials. Cellulose derivative viz. 2,2,6,6-tetramethylpiperidine-1-oxylradical (TEMPO)-mediated oxidized nanocellulose (TOCNF) was used to modulate the crystal growth of ZIF-8 (denoted as CelloZIF-8) and ZIF-L (CelloZIF-L). The synthesis procedure occurred in water at room temperature with and without NaOH. The reaction parameters such as the sequence of the chemical's addition and reactant molar ratio were investigated. The phases formed during the crystal growth were monitored. The data analysis ensured the presence of zinc hydroxide nitrate nanosheets modified TOCNF during the crystallization of CelloZIFs. These phases were converted to pure phases ofCelloZIF-8 and CelloZIF-L. The resultant CelloZIFs materials were used for the adsorption ofcarbon dioxide (CO2), metal ions, and dyes. The materials exhibited high selectivity with reasonable efficiency (100%) toward the adsorption of anionic dyes such as methyl blue (MeB). They can also be used as a catalyst for dye degradation via hydrogenation with an efficiency of 100%. CelloZIF crystals can be loaded into a filter paper for simple, fast, and selective adsorption of MeB from a dye mixture. The materials are recyclable for five cycles without significant loss of their performance. The mechanisms of adsorption and catalysis were also investigated.

Automated summary

Crystal growth of zeolitic imidazolate frameworks (ZIFs) on biopolymers such as cellulose offers a promising method for obtaining hybrid materials combining natural and synthetic components. By using TEMPO-mediated oxidized nanocellulose (TOCNF) derived from cellulose, the crystal growth of CelloZIF-8 and CelloZIF-L was modulated. These materials demonstrated high selectivity and efficiency in adsorbing CO2, metal ions, and anionic dyes such as methyl blue (MeB), as well as serving as catalysts for dye degradation. The materials can be recycled multiple times without significant loss of performance, and their adsorption and catalysis mechanisms were investigated.