关键词: MXene, 微晶纤维素, 复合气凝胶, 亚甲基蓝, 染料吸附

Abstract: At present, the discharge of wastewater from the traditional textile industry is increasing, and the discharge of dye wastewater accounts for about 35% of the total industrial wastewater, which seriously affects human health and ecological environment. Therefore, it is of great significance for environmental protection to develop efficient and convenient methods to remove organic dyes from water. As a kind of sustainable renewable energy, cellulose in biological matrix materials can not only reduce environmental pollution, but also has been widely used in the treatment of printing and dyeing wastewater due to its excellent physical and chemical properties. However, the inherent adsorption capacity of pure cellulose is quite low. In order to promote the adsorption effect of cellulose materials on dyes, fixing MXene on the 3D frame of cellulose aerogels not only helps to dope nano materials, but also can enhance the adsorption capacity of cellulose aerogels. As a new two-dimensional nanomaterial, MXene has a unique layered structure and terminal hydroxyl (−OH), oxygen (−O), fluorine (−F) and other functional groups, which makes it have good hydrophilicity and rich active sites. According to the needs of printing and dyeing wastewater treatment, MXene has been widely used in dopants of various substrates, showing the promising application prospect of MXene in the treatment of environmental dye wastewater.
Therefore, in order to obtain better dye adsorption results, the composite aerogel prepared by freeze-drying MXene doped into the traditional pure cellulose framework has the advantages of high porosity and high adsorption rate. The preparation of MXene and the comparison of adsorption effects of the composite aerogel and the pure gas gel on methylene blue dye were studied. The micro morphology and chemical structure of MXene as well as the adsorption performance of the composite aerogel were characterized by analysis and testing. The results showed that MXene materials had been successfully prepared, and the adsorption effect of the MXene-doped composite aerogel was 60% higher than that of the pure cellulose aerogel gel. Then, the adsorption effects of methylene blue on different mass adsorbents, initial concentrations of the methylene blue solution and ambient temperatures were compared. The study showed that when the mass of the adsorbent was 100 mg, the initial concentration was 50 mg·L-1, and the ambient temperature was 20 ℃, the composite aerogel had the best adsorption effect on the methylene blue solution, with a removal rate of 80%, making most of the methylene blue adsorbed.
In this paper, the adsorption potential of MXene was fully developed, and the composite materials were prepared by blending and doping, which effectively absorbed a certain volume and concentration of the dye solution. The research findings of composite or modification of new nanomaterials on traditional biological substrates will provide inspiration and suggestions for the treatment of printing and dyeing wastewater.

Key words: MXene, MCC, composite aerogel, methylene blue, dye adsorption