Synergistic Effect of Ti<sub>3</sub>C<sub>2</sub>T<sub><i>x</i></sub> MXene Nanosheets and Tannic Acid–Fe<sup>3+</sup> Network in Constructing High-Performance Hydrogel Composite Membrane for Photothermal Membrane Distillation
Na Zhang, Jiaojiao Zhang, Xiaohui Zhu, Shideng Yuan, Dong Wang, Haoran Xu, Zhining Wang
Abstract
Photothermal membrane distillation (PMD) has emerged as a promising and sustainable approach for seawater desalination and wastewater purification. However, the wide application of the technique is severely impeded by low freshwater production and membrane fouling/wetting issues. Herein, we developed an advanced hydrogel-engineered membrane with simultaneously enhanced photothermal conversion capacity and desired fouling and wetting resistance for PMD. By the synergies of photothermal Ti 3 C 2 T x MXene nanosheets and the tannic acid–Fe 3+ network in the hydrogel, the membrane was endowed with excellent surface self-heating ability, yielding the highest freshwater production rate (1.71 kg m –2 h –1 ) and photothermal efficiency among the fabricated hydrogel composite membranes under 1 sun irradiation. Meanwhile, the PMD membrane could robustly resist oil-induced fouling and surfactant-induced wetting, significantly extending the membrane lifespan in treating contaminated saline water. Furthermore, when desalinating real seawater, the membrane exhibited superior durability with a stable vapor flux and excellent ion rejection (e.g., 99.24% for boron) for 100 h.