The optimum solvent for Nb2Se9 dispersion, which is a new type of one dimensional (1D) material, is investigated. Among several solvents (16 solvents in total), strong dispersion was observed in benzyl alcohol, isopropyl alcohol, isobutyl alcohol, and diacetone alcohol, which have medium dielectric constants in the range of 10 to 30 and surface tension in the range of 25 to 35 mJ m−2. 1D Nb2Se9 chains, whose size is less than 10 nm, are well dispersed and it is possible to disperse mono-chains of 1 nm or less in a specific dispersion region. The 1D unit chain with dangling bond free surface and high volume to area ratio is expected to be used in applications that utilize the surface of the material. Such dispersion is an important first step towards various potential applications and is an indispensable scientific goal for the practical applications of Nb2Se9.

A novel one‐dimensional (1D) inorganic material, Nb2Se9, which can be separated into atomic‐level, is synthesized through chemical reaction between Nb and Se sources. Nb2Se9 and Se crystals are formed under an excess Se condition to avoid other phase such as NbSe3, and the residual Se can be removed by heat treatment; thus, high‐purity Nb2Se9 crystals can be obtained. The one‐atom‐thick level Nb2Se9 nanochains are successfully obtained by mechanical exfoliation and dispersion in a solvent. The covalently bonded Nb2Se9 chain, when isolated from its three‐dimensional bulk material, is expected to have unique physical properties based on electron confinement in the 1D chain structure and the absence of dangling bonds. In addition, it has excellent thermal stability (up to 500 °C) and can be widely used in various fields.

The enlargement of the Stern layer distance caused by this ion exchange improves the dispersibility of (Mo3Se3−)∞ chains and also prevents the re-bundling and aggregation of nanowires in aqueous solutions, even at high concentrations (1 mg mL−1).