I think @Ayoub Maalaisse mean phosphorene.

A nanotube of phosphorus, also known as a phosphorene nanotube, is a tube-shaped structure composed of phosphorus atoms.

Phosphorene nanotubes have unique properties that make them potentially useful in a wide range of applications, such as electronics, optoelectronics, and energy storage. These properties include high electrical conductivity, excellent mechanical strength, and high surface area.

The fabrication of phosphorene nanotubes is still in the early stages of research, but there have been some promising results using computational methods and experimental techniques such as chemical vapor deposition (CVD) and solution-based synthesis.

In addition to their potential applications, the study of phosphorene nanotubes is also important for understanding the fundamental properties of low-dimensional materials and for exploring new materials with novel properties.

Not strictly a tube, but the complex structure of violet phosphorus might interest you:

Article The structure and electronic properties of crimson phosphorus

and

https://doi.org/10.1002/anie.201912761