Facile fabrication of an effective nanocellulose-based aerogel and removal of methylene blue from aqueous system

Water pollution caused by organic dyes is becoming a critical global environmental concern. Here, we designed a novel and green aerogel by freeze-drying composed of cellulose nanofibril (CNF) and graphene oxide-silica (GO-silica), which could efficiently remove organic dyes from contaminated water and solve the recycle of nanohybrid materials. Subsequently, the as-synthesized aerogels were evaluated for the adsorption of methylene blue (MB) form aqueous solution. The results showed that GO-silica particles were synthesized successfully and displayed a low degree of crystallinity. And compared to pure CNF aerogels, the composite aerogels exhibited superior adsorption performances, with the maximum value of 608.4 mg/g. Furthermore, the adsorption kinetic and isotherm MB on the composite aerogels obeyed the pseudo-second-order and the Langmuir model, respectively. The Langmuir model fitting yielded a maximum adsorption capacity of 623.9 mg/g for MB. According to the results of the mean free energy (E) and the Elovich isotherm model, the decolorization applying CNF and composite aerogels was occurred chemically. This aerogel introduced here is easy to fabricate, efficient, and biodegradable, which makes it a potential alternative for wastewater treatment.