Enhanced interfacial interactions and enriched active sites in self-assembly amino-functionalized bacterial cellulose/MXene composite for wastewater treatment

With rapid industrialization and economic growth, the serious environmental pollution caused by heavy metals and dyes is a pressing issue to be solved. The efficient construction of enriched active sites and porous structures is the key to obtain water purification material for pollution removal. In this study, an efficient electrostatic self-assembly strategy to achieve amino-functionalized bacterial cellulose/Ti3C2Tx MXene (ABC/MX) composite with a 3D cross-linked porous structure has been proposed. Experimental characterization and theoretical calculations reveal that the successful incorporation of amino groups not only enhances the interfacial interactions between BC nanofibers and Ti3C2Tx nanosheets, but also increases the active sites available for adsorption. The results highlight that the ABC/MX composite exhibits exceptional removal efficiency, with maximum adsorption capacities of 200.7 mg/g for Cr(VI) and 1103.7 mg/g for Congo red (CR). In particular, it reveals that the multifaceted adsorption processes of Cr(VI) and CR involve electrostatic interactions, reduction reactions, chelation, and hydrogen bonding effects. These findings highlight a versatile strategy for synthesizing BC-based adsorbents with remarkable adsorption properties and are suitable for practical wastewater treatment applications.