Elastic 2D graphene/ZIF-8 nanosheets aerogels for efficient and sustainable As(III) removal from water

Elastic two-dimensional (2D) metal-organic framework (MOF) nanosheet-based aerogels present a promising architecture for water remediation, yet often suffer from structural fragility and reduced porosity. Herein, we report an elastic 2D ZIF-8/graphene nanosheet aerogel (E-GZNA) synthesized via a facile cross-linking strategy using carboxymethyl cellulose (CMC) as a binder, overcoming the aggregation and recyclability bottlenecks of conventional MOF adsorbents. The resulting hierarchical porous structure of E-GZNA enabled rapid As(III) mass transfer, while CMC enhanced mechanical elasticity, allowing 50% compression for 50 cycles with 80% stress retention. E-GZNA exhibited a maximum As(III) adsorption capacity of 73.6 mg/g, significantly outperforming most macroscopic adsorbents. XPS and FTIR analyses revealed adsorption mechanisms involving Zn-O-As and N-O-As bond formation. DFT further confirmed As(III) adsorption on both sites with comparable adsorption energies. Fixed-bed column experiments further demonstrated effective arsenic removal to below the WHO standard, highlighting its potential for practical water treatment applications. This work advances MOF-based aerogels by integrating elasticity, high adsorption efficiency, and recyclability for sustainable As(III) removal.