Nanocellulose and Graphene Oxide Aerogels for Adsorption and Removal Methylene Blue from an Aqueous Environment

Abstract

The characteristics of aerogel materials such as the low density and large surface area enable them to adsorb large amounts of substances, so they show great potential for application in industrial wastewater treatment. Herein, using a combination of completely environmentally friendly materials such as cellulose nanofibers (CNFs) extracted from the petioles of the nipa palm tree and graphene oxide (GO) fabricated by simple solvent evaporation, a composite aerogel was prepared by a freeze-drying method. The obtained aerogel possessed a light density of 0.0264 g/cm 3 and a porosity of more than 98.2%. It was able to withstand a weight as much as 2500 times with the maximum force (1479.5 N) to break up 0.2 g of an aerogel by compression strength testing and was stable in the aquatic environment, enabling it to be reused five times with an adsorption capacity over 90%. The CNF/GO aerogel can recover higher than 85% after 30 consecutive compression recovery cycles, which is convenient for the reusability of this material in wastewater treatments. The obtained aerogel also showed a good interaction between the component phases, a high thermal stability, a 3D network structure combined with thin walls and pores with a large specific surface area. In addition, the aerogel also exhibited a fast adsorption rate for methylene blue (MB) adsorption, a type of waste from the textile industry that pollutes water sources, and it can adsorb more than 99% MB in water in less than 20 min. The excellent adsorption of MB onto the CNF/GO aerogel was driven by electrostatic interactions, which agreed with the pseudo-second-order kinetic model with a correlation coefficient R 2 = 0.9978. The initial results show that the CNF/GO aerogel is a highly durable “green” light material that might be applied in the treatment of domestic organic waste water and is completely recoverable and reusable.

Polydopamine-Modified Cellulose Nanofibril Composite Aerogel: An Effective Dye Adsorbent

“…MB is widely used in the textile industry with a heterocyclic aromatic structure and can cause many adverse impacts after its intake, such as nausea, vomiting, and mental confusion. 49 The PCNF composite aerogel with negatively charged surfaces may have a strong adsorption capacity toward the positively charged MB dyes. Moreover, the PDA layer may also play a role as an electron acceptor through π−π stacking interactions with the conjugated structures of MB (unsaturated double bonds).…”

“…MB is widely used in the textile industry with a heterocyclic aromatic structure and can cause many adverse impacts after its intake, such as nausea, vomiting, and mental confusion . The PCNF composite aerogel with negatively charged surfaces may have a strong adsorption capacity toward the positively charged MB dyes.…”

Cellulose nanofibrils–graphene hybrids: recent advances in fabrication, properties, and applications

“…Moreover, it was found that this hybrid ensures an effective easy separation process and reusability, rendering it a potential, economical and effective adsorbent in antibiotic removal from wastewater. Recently, Nguyen and coworkers prepared aerogels based on CNFs/GO using a freeze-drying method for removal and adsorption of methylene blue from aqueous environments, 119 as schematized in Fig. 11(C).…”

Ultralight, Mechanically Enhanced, and Thermally Improved Graphene-Cellulose-Polyethyleneimine Aerogels for the Adsorption of Anionic and Cationic Dyes

“…Dyes in water can adversely affect ecosystems and human health. Adsorption has become one of the most effective wastewater treatment methods because of its low cost, simple operation, and high efficiency [ 1 , 2 , 3 ]. Graphene aerogels are porous (porosity can reach more than 99%), which can provide sufficient transport channels for the diffusion of pollutants when they are adsorbed to improve the adsorption efficiency of adsorbents [ 4 , 5 ].…”