Environmentally friendly nanocomposites based on cellulose nanocrystals and polydopamine for rapid removal of organic dyes in aqueous solution

It remains a great challenge to develop environmentally friendly adsorbents with large adsorption capacity, fast adsorption speed, and high regenerability from eco-friendly and cheap biomaterials. Herein, we present a simple and green approach to prepare biocompatible adsorbents with two environmentally friendly raw materials, cellulose nanocrystals (CNCs) and mussel-inspired polydopamine (PDA). The resultant CNC@PDA nanocomposites show a ditinct core-shell structure with a very thin PDA coating, providing a high specific surface area of 107.2 m(2)/g for adsorption sites. The CNC@PDA nanocomposites have an exceptionally high adsorption capacity of up to 2066.72 mg/g for MB and can rapidly sequester MB from water within 5 min at high initial MB concentration of 500 mg/L. Moreover, CNC@PDA nanocomposites can be regenerated by a simple method and maintain high adsorption capacity for MB even after multiple adsorption-desorption cycles. The work provides promising results for the developed CNC@PDA materials as economical adsorbent materials for effective and efficient dye decontamination of the wastewater.