Scalable Synthesis of MXene Scrolls

MXenes represent a promising class of 2D carbides, nitrides, and carbonitrides known for their high electrical conductivity, hydrophilicity, mechanical strength, and unique optoelectronic properties, which have led to numerous applications. However, their scalable synthesis in 1D morphology, such as nanotubes or scrolls, has not been demonstrated yet. This work presents a versatile and scalable method for manufacturing MXene scrolls, including Ti₂CT_x, Ti₃C₂T_x, Ti₃CNT_x, V₂CT_x, Nb₂CT_x, and Ta₄C₃T_x. We demonstrate a scalable and high-yield production up to 10 g of pure scrolls with precise control over their alignment and morphology. Properties of scrolls differ from 2D flakes; e.g., a freestanding film made of scrolled Nb₂CT_x presents 33 times increase in electrical conductivity and shows a superconducting state below 5.2 K. Films of MXene scrolls exhibit 3 times lower density and enhanced mass transport compared to flakes, resulting in an improved performance in supercapacitor electrodes and humidity sensors. The dispersion of the scrolls in water behaves like an electrorheological fluid. Aligning scrolls in an electric field allows for circuit switching between electrically insulating and conductive states. These scrolls can be assembled into vertically aligned MXene forests, fibers, and other architectures. The availability of 1D MXene scrolls offers exciting opportunities in many fields.