Ti₃C₂T MXene/carbon nanofiber multifunctional electrode for electrode ionization with antifouling activity

Scaling, corrosion, and biofouling have enormous economic impacts and potential safety hazards to circulating cooling water systems in industry. Capacitive deionization (CDI) technology, through the rational design and construction of electrodes, is expected to tackle these three problems simultaneously. Here, we report a flexible self-supporting Ti₃C₂T MXene/carbon nanofiber film fabricated by electrospinning. It served as a multifunctional CDI electrode with high-performance antifouling and antibacterial activity. One-dimensional (1D) carbon nanofibers bridging two-dimensional (2D) Ti₃C₂T nanosheets formed a three-dimensional (3D) interconnected conductive network, which expedited the transport and diffusion kinetics of electrons and ions. Meanwhile, the open-pore framework of carbon nanofibers anchored Ti₃C₂T , which alleviated self-stacking and enlarged the interlayer space of Ti₃C₂T nanosheets, thereby offering more sites for ion storage. The electrical double layer-pseudocapacitance coupled mechanism endowed the prepared Ti₃C₂T /CNF-14 film with high desalination capacity (73.42 ± 4.57 mg g^-1 at 60 mA g^-1), rapid desalination rate (3.57 ± 0.15 mg g^-1 min^-1 at 100 mA g^-1), and longish cycling life, and outperformed other carbon- and MXene-based electrode materials. More importantly, on account of the desirable hydrophilicity, good dispersion, and sufficient exposure of the sharp edges of Ti₃C₂T nanosheets, Ti₃C₂T /CNF-14 concurrently delivered an impressive inactivation efficiency against Escherichia coli, reaching 99.89% within 4 h. Our study draws attention to the simultaneous killing of microorganisms through the intrinsic characteristics of well-designed electrode materials. These data could aid application of high-performance multifunctional CDI electrode materials for treatment of circulating cooling water.