  Carbon is an extremely versatile element and carbon allotropes are very
useful in all aspects of life and scientific research. T-carbon is a novel
carbon allotrope with many appealing properties. Since the proposal of
T-carbon, there has been a lot of intensive studies devoted to its physical,
chemical, optical, magnetic, thermoelectrical and topological properties and
possible applications in diverse areas in recent years. In this review, we
provide a comprehensive review on the advances of the experiments, intriguing
properties and various potential applications of T-carbon in energy storage,
optoelectronics, thermoelectrics, topological states, etc. As intercalation and
doping are effective methods to modify the electronic structure of materials or
even to convert into sparkly different new structures or phases, we also
discuss different atom doped T-carbon, which exhibit more intriguing properties
and lead to promising potential applications in solar cells, photocatalysis,
magnetism, superconductivity and so on. In addition, it is interesting to
mention that the hydrogenated T-carbon molecules werefound to be possibly
related to the physical origin of the UV extinction feature in interstellar
medium that has been the half-century long unsolved puzzle. Many novel
derivative structures either derived or inspired from T-carbon are included as
well. Finally, we give prospects and outlook for future directions of study on
T-carbon and related structures.
