Inorganic Nanotubes and Fullerene–Like Nanoparticles from Layered (2D) Compounds

Abstract

Soon after carbon nanotubes were discovered by Iijima (Nature, 1991), we proposed (Nature, 1992) that inorganic layered compounds, likeWS2, are unstable in the planar form in the nanorange. Under proper chemical conditions, this inherent instability leads to folding of the layers and formation of hollow closed‐cage structures, that is, nanotubes (INT) and fullerene‐like (IF) nanoparticles. Given the elastic energy of the bending, formation of these closed‐cage nanostructures is pending on providing enough energy, that is, high temperature reactions. In the following years, we and others have preparedIF/INTfrom numerous layered compounds and studied their properties. Numerousab initiostudies were also dedicated to the study of nanotubes from different layered compounds. Recent developments in this field will be described, including the study of nanotubes from “misfit” compounds; doping of theIF/INT; ultrahigh temperature synthesis ofIF/INT; their optical and electrical properties, and so on. The mechanical properties of individual nanotubes were studied experimentally and usingab initiocalculations.Studying in detail the growth‐mechanism ofIF/INTof several compounds, mostlyWS2andMoS2we were able to scale‐up their synthesis to mass production. Several applications for theseIF/INT, especially as superior solid lubricants and for reinforcing polymer nanocomposites, were put forward. The successful commercialization of products based on these ideas will be briefly described.