MXene-based composite aerogels with bifunctional ferrous ions for the efficient degradation of phenol from wastewater

Herein, MXene-based composite aerogel (MXene-Fe²⁺ aerogel) are constructed by a one-step freeze-drying method, using Ti₃C₂T_x MXene layers as substrate material and ferrous ion (Fe²⁺) as crosslinking agent. With the aid of the Fe²⁺ induced Fenton reaction, the synthesized aerogels are used as the particle electrodes to remove phenol from wastewater with three-dimensional electrode technology. Combined with the dual roles of Fe²⁺ and the highly conductive MXene, the obtained particle electrode possesses extremely effective phenol degradation. The effects of experiment parameters such as Fe²⁺ to MXene ratio, particle electrode dosage, applied voltage, and initial pH of solution on the removal of phenol are discussed. At pH = 2.5, phenol with 50 mg/L of initial concentration can be completely removed within 50 min at 10 V with the particle electrode dosage of 0.56 g/L. Finally, the mechanism of degradation is explored. This work provides an effective way for phenol degradation by MXene-based aerogel, which has great potential for the degradation of other organic pollutants in wastewater.