Van der Waals Welding of Carbon Nanotubes with Near‐Limit High Strength

The strength of carbon nanotube (CNT) bundles and fibers is generally much lower than that of single CNTs, the short length of CNT components results in the assembly strength can only be contributed by the weak shearing interaction between CNTs. Here, the welding of CNTs by a fast chemical‐vapor‐deposition self‐assembly (FCVDS) technique using TiO 2 nanoparticles as the solder is reported. It is simple, fast, pressure‐free, applicable to ambient conditions, and can weld samples with macroscale length. The welded junctions have a mechanical strength approaching the tensile strength of a single CNT. Whereas the interface interaction between TiO 2 and CNTs is only contributed by Van der Waals forces, avoiding the destruction of the defect‐free structure of CNTs. The solder mass can be only ≈1 wt% of welded CNTs.