The rapid expansion of the textile dyeing industry has created an urgent need for high-performance dye wastewater treatment materials due to the limitations of traditional adsorbents in efficiency and separability. Herein, we report the synthesis of ultralight, cost-effective aerogel adsorbents by introducing triethylenetetramine (TETA) into α-cellulose (CU). The resulting CU/TETA-0.25 aerogel displays outstanding adsorption capacities for Congo Red and indigo dyes, reaching 575.7±20 mg/g and 516.4±20 mg/g, respectively. Remarkably, less than 1 g of this aerogel continuously filters over 35 L (50 mg/L) of deeply colored red–blue dye wastewater to near transparency. Its high adsorption efficiency remains stable even under simultaneous exposure to multiple ions, organic compounds, and pH fluctuations. Mechanistic insights, derived from SEM, EDX, and XPS analyses and first-principles calculations (including molecular structure optimization, frontier molecular orbital distribution, weak interaction, and charge density difference), confirm that the –OH and –NH₂ groups on CU/TETA-0.25 drive dye adsorption through hydrogen bonding, supplemented by electrostatic and van der Waals interactions. Owing to its mass-producibility, lightweight nature, and low cost, CU/TETA-0.25 holds great promise for large-scale applications in mitigating water pollution caused by mixed dyes.
Yunlei Shi,Dazhen Xiong,Zhiyong Li,Huiyong Wang,Jikuan Qiu,Hucheng Zhang,Jianji Wang
In recent years, metal–organic frameworks (MOFs) have been explored as emulsifiers for the fabrication of Pickering emulsions and then used for hybrid material synthesis and interface catalysis. Nevertheless, stimuli-responsive Pickering emulsions stabilized by MOFs have been rarely reported so far, although they are of great importance for fundamental research studies and practical applications. Herein, for the first time, triethylenetetramine (TETA)-functionalized MOFs (ZIF-90/TETA) have been designed, synthesized, and used for fabricating CO2-/N2-response Pickering emulsions. It is shown that even at the ZIF-90/TETA content of 0.25 wt %, the functional MOF can still efficiently emulsify n-hexane and water to form a high internal phase Pickering emulsion. Importantly, the Pickering emulsion can be easily and reversibly switched between emulsification and demulsification by bubbling of CO2 and N2 alternatively at atmospheric pressure. The possible mechanism of the CO2/N2 switchable emulsion is investigated by zeta potential, water contact angle, interfacial tension, 13C NMR spectroscopy, and an optical microscope. It is found that the acid–base reaction of CO2 with TETA anchored on the surface of ZIF-90 leads to the production of hydrophilic ammonium bicarbonate and carbamate, which results in the emulsification of the Pickering emulsion. However, when N2 is bubbled to remove CO2, the reverse reaction takes place to cause the demulsification of the Pickering emulsion. Moreover, the CO2/N2 switchable Pickering emulsion has been successfully used as a microreactor for Knoevenagel reactions to demonstrate a highly efficient integration of chemical reaction, product separation, and ZIF-90/TETA recycling for a sustainable chemical process.
危险品化学品经营许可证（带存储）