A general strategy for hydrophobic 2D Ti₃C₂MXene membrane fabrication for efficient and stable solar desalination.

MXene-based materials are promising electrode materials for electrochemical capacitors (ECs) due to their unique two-dimensional layered structure, high surface area, remarkable chemical stability, and electrical conductivity. TiO₂ nanoparticles decorated Ti₃C₂ MXene were synthesized through a simple in situ hydrolysis and heat-treatment process and subsequently fabricated as an electrode for ECs. The as-prepared Ti₃C₂, TiO₂, and TiO₂-Ti₃C₂ were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. The results indicated that TiO₂ nanoparticles with a diameter of less than 30 nm were decorated onto the Ti₃C₂ MXene nanosheets. The resulting composites exhibited significantly higher specific capacitance of 143 F g⁻¹ at 5 mV s⁻¹, which was 1.5 times that of pure Ti₃C₂ (93 F g⁻¹). Moreover, TiO₂-Ti₃C₂ showed excellent cycling stability, retaining ∼92% of its initial capacitance after 6000 cycles. These results suggest that TiO₂-Ti₃C₂ nanocomposite has the potential as an electrode material for high-performance energy storage devices.

A novel organ-like MXene-Ti₃C₂ nanomaterial was successfully prepared by etching Al from Ti₃AlC₂ in HF at room temperature and then used to immobilise hemoglobin (Hb) to fabricate a mediator-free biosensor with an oxidized surface. MXene-Ti₃C₂ and its morphology were well characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the physical and electrochemical properties of as-obtained samples were studied by UV-vis diffuse reflectance spectra (DRS) and the electrochemical workstation. Spectroscopic and electrochemical results confirmed that MXene-Ti₃C₂ exhibited an excellent enzyme immobilization ability with biocompatibility for redox protein, displaying good protein bioactivity and stability. Due to the special structure and properties of MXene-Ti₃C₂, the direct electron transfer of Hb is facilitated and the prepared biosensors displayed good performance for the detection of H₂O₂ with a wide linear range of 0.1–260 μM for H₂O₂, as well as an extremely low detection limit of 20 nM (based on a signal-to-noise ratio of 3) for H₂O₂. The immobilization of proteins onto the surface of MXene-Ti₃C₂ is shown to be an efficient method for the development of a new class of sensitive, stable, and promising electrochemical biosensors.