Holey Ti3C2Tx nanosheets membrane with high PM removal efficiency for air pollution

Developing air filters with high efficiency, low airflow resistance, good chemical and thermal stability is a great challenge for PM purification applications. MXene membranes with controlled interlayer nano-channels and abundant hydrophilic groups exhibit excellent separation potential. However, the easy stacking between neighboring nanosheets in two-dimensional lamellar membranes increases the resistance during the separation process. In this study, metal oxides were assembled with Ti(3)C(2)Tx nanosheets by electrostatic interaction, and holey Ti(3)C(2)Tx (H-Ti(3)C(2)Tx) nanosheets with abundant through-hole structures were prepared by calcination and etching with a specific surface of 13.2 m(2)g(-1), 6 times higher than that of Ti(3)C(2)Tx (2.2 m(2)g(-1)). H-Ti(3)C(2)Tx nanosheet membranes with transverse and longitudinal channels were produced using vacuum filtering. The membrane has excellent PM filtration performance, with filtration efficiency higher than 94.59% for PM 0.3 and 99.97% for PM 2.5 and 99.99% for PM 10.0, respectively, and the pressure drop of 120 Pa after 12 h of operation, which is better than that of pure Ti(3)C(2)Tx membrane (>1300 Pa). Excellent PM filtration was also demonstrated under high humidity conditions. Our findings provide a scalable strategy for the synthesis of holes MXene materials as well as demonstrate their potential in air purification.

Automated summary

Developing air filters with high efficiency and low airflow resistance is challenging. In this study, MXene membranes with controlled nano-channels and abundant hydrophilic groups were produced. H-Ti(3)C(2)Tx nanosheet membranes with through-hole structures were prepared and showed excellent PM filtration performance.