One-Dimensional New Carbon Allotrope: Carbon Chain

Carbon chain( CC) is a new type of carbon allotrope with one-dimensional sp-hybridized structure. Its unique chemical bonds result in superior properties than that of fullerene. graphene. and carbon nanotubes. For example. theoretical calculations predict that the mechanical strength of the CC is several times greater than that of graphene. Also. the thermal conductivity of the CC is similar to that of graphene and carbon nanotubes. In addition. the CC is a semiconductor with direct band gap. which can be tuned via its length. i.e.. the longer the CC. the smaller the band gap. Although the research on the CC has bee started as early as the 19th century. making progress was indeed difficult and slow. Recently. several breakthroughs in research on CC has attracted extensive attention to CC again all over the world. In this review. the concept. structure. and properties of the CC are first introduced. On this basis. typical synthesis methods and applications are detailedly presented. Especially. several recent major breakthroughs in the field of the CC are highlighted. Most importantly. perspectives on the research directions of the CC are indicated. We hope that this review is able to attractdomestic and international peers' attention on this new type of one-dimensional sp-hybridized carbon allotrope.