Substitutional heteroatom doping is a promising route to modulate the outstanding material properties of carbon nanotubes and graphene for customized applications. Recently, (nitrogen-) N-doping has been introduced to ensure tunable work-function, enhanced n-type carrier concentration, diminished surface energy, and manageable polarization. Along with the promising assessment of N-doping effects, research on the N-doped carbon based composite structures is emerging for the synergistic integration with various functional materials. This invited feature article reviews the current research progress, emerging trends, and opening opportunities in N-doped carbon based composite structures. Underlying basic principles are introduced for the effective modulation of material properties of graphitic carbons by N-doping. Composite structures of N-doped graphitic carbons with various functional materials, including (i) polymers, (ii) transition metals, (iii) metal oxides, nitrides, sulphides, and (iv) semiconducting quantum dots are highlighted. Practical benefits of the synergistic composite structures are investigated in energy and catalytic applications, such as organic photovoltaics, photo/electro-catalysts, lithium ion batteries and supercapacitors, with a particular emphasis on the optimized interfacial structures and properties.

Ti₃C₂T_xMXene is an emerging class of two-dimensional nanomaterials with exceptional electroconductivity and electrochemical properties, and is promising in the manufacturing of multifunctional macroscopic materials and nanomaterials. Herein, we develop a straightforward, continuously controlled, additive/binder-free method to fabricate pure MXene fibers via a large-scale wet-spinning assembly. Our MXene sheets (with an average lateral size of 5.11 μm²) are highly concentrated in water and do not form aggregates or undergo phase separation. Introducing ammonium ions during the coagulation process successfully assembles MXene sheets into flexible, meter-long fibers with very high electrical conductivity (7,713 S cm⁻¹). The fabricated MXene fibers are comprehensively integrated by using them in electrical wires to switch on a light-emitting diode light and transmit electrical signals to earphones to demonstrate their application in electrical devices. Our wet-spinning strategy provides an approach for continuous mass production of MXene fibers for high-performance, next-generation, and wearable electronic devices.

The discovery of graphene oxide liquid crystal (GOLC) has enabled a broad spectrum of novel graphene-based functional materials and triggered the development of other 2D-based liquid crystal systems.