Interaction of Polar and Nonpolar Polyfluorenes with Layers of Two-Dimensional Titanium Carbide (MXene): Intercalation and Pseudocapacitance

This article provides insight into the interaction of synthetic conjugated polymers [polyfluorene derivatives (PFDs)] with layers of two-dimensional titanium carbide (Ti3C2Tx). Three derivatives with nonpolar, polar, and charged nitrogen-containing functionalities were synthesized via the Suzuki polycondensation reaction. The organic–inorganic PFD/Ti3C2Tx hybrids were prepared and characterized using X-ray diffraction and a range of microscopic and spectroscopic techniques to elucidate the host–guest interaction mechanism. We show that polar polymers with charged nitrogen-containing ends have the strongest interaction with the Ti3C2Tx layers, yielding an increase in interlayer spacing and large shifts in spectroscopic peaks. Furthermore, the effect of polymer backbone juxtaposition between Ti3C2Tx layers on pseudocapacitance is discussed in detail. Our results suggest that new organic materials capable of intercalation between the layers of Ti3C2Tx and other MXenes may be used in the design of hybrid structures for high-performance energy storage applications and beyond.