Large-scale fabrication of oppositely charged MXene (Ti₃C₂T_x) membrane for enhanced osmotic power generation

초록

The large-scale production of MXene films is in high demand for various applications, but meeting industrial standards remains challenging. Adding nanofluidic channels to reverse electrodailysis devices can make osmotic power generators work much better by letting ions move quickly and selectively. However, technical challenges related to scalable fabrication and the development of ion-selective membranes hinder progress in creating costeffective generators. In this study, we present a doctor-blade coating method for fabricating large-area MXene membranes. This technique enables continuous and scalable coatings, with thickness easily adjustable from the nanometer to the micrometer scale, while also improving nanosheet alignment. Ion-transportation tests are conducted using a fabricated membrane with an optimal thickness of approximately 25 mu m. Efficient energy- generating membranes are synthesized using negatively and positively charged MXene (N-MXene and PMXene). This approach shows great potential for achieving non-swelling properties, excellent selectivity, and improved power density in osmotic power generation. The oppositely charged membrane (N/P-MXene) cell provides outstanding stability against swelling in aqueous environments for up to 25 days. Additionally, it demonstrates high selectivity (0.97) and delivers a superior power density of 22.6 W/m2 when used in seawater- river water-seawater electrolyte solutions. These membranes can be easily fabricated using simple etching and surface charging techniques, indicating promising scalability.

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