As a family member of MXenes, Ti₃C₂T_x has received worldwide interest due to its excellent electrochemical energy storage properties. However, freestanding Ti₃C₂T_x films synthesized by direct assembly of two-dimensional (2D) sheets have relatively low specific capacitance and rate capability due to the low ion transport efficiency between Ti₃C₂T_x (MXene) sheets. Here, we demonstrate an effective method to improve the electrochemical performance of MXene-based electrodes by incorporating MXene sheets with conducting polymers. A Ti₃C₂T_x/polyaniline (MXene/PANI) composite was fabricated by chemical oxidative polymerization of aniline monomers on the surface of Ti₃C₂T_x sheets. Benefiting from the highly conductive open structure, efficient ion and electron transport and high electrochemical activity of Ti₃C₂T_x and PANI, the MXene/PANI electrode presents a maximum specific capacitance of 556.2 F g⁻¹ at a current density of 0.5 A g⁻¹, an impressive rate capability (high capacitance retention of 78.7% at 5 A g⁻¹) and excellent cycling stability with a high capacitance retention of 91.6% after 5000 cycles at 5 A g⁻¹. Therefore, this paper provides a facile and effective method to achieve high performance MXene-based electrode materials for supercapacitors.

New mesoscopic hollow sphere sorbents composed of CaO/Ca₁₂Al₁₄O₃₃ with tunable cavity size are successfully synthesized using sulfonated polystyrene (PS) as hard template. The monodispersed hollow nanostructure provides the void space that can buffer against the large volume change during the carbonation/calcination cycles. The as-prepared high temperature CO₂ sorbents have large specific surface areas, fast adsorption kinetics, significantly improved CO₂ adsorption capacity and cyclic reaction stability. This method opens up new opportunities in the development of high performance next-generation high temperature CO₂ sorbents.

Covalently grafted polyethyleneimine–hydroxylated three-dimensional graphene nanocomposites prepared by ring-opening polymerization exhibit superior CO₂ capture behavior.

Ti ₃ C ₂ (OH) x –polyethyleneimine-1,2-butylene oxide (Ti ₃ C ₂ /PEI/BO) nanocomposite with superior CO ₂ capture performance.