Advances in fabrication, properties, and applications of nanotube technologies

Abstract Nanotubes, such as carbon nanotubes (CNTs), zinc oxide (ZnO) nanotubes, titanium dioxide (TiO 2 ) nanotubes, gallium nitride (GaN) nanotubes, tin dioxide (SnO 2 ) nanotubes, and transition metal dichalcogenides (TMDs), are important nanomaterials in different areas of technology because of their distinct chemical and physical characteristics. The current status of several types of nanotubes, such as CNTs, ZnO nanotubes, TiO 2 nanotubes, GaN nanotubes, SnO 2 nanotubes, and TMDs, is thoroughly examined in this review paper. We discuss the technological difficulties in producing and scaling these materials, highlighting the requirement for exact control over their size, shape, and structural integrity in order to be used in electronics, sensors, and energy storage. We recognize common problems that impede the efficiency of these nanotubes, such as irregularities in wall thickness, uneven crystal quality, and the introduction of defects during large-scale production, through an extensive examination of production methods, including chemical vapor deposition (CVD), hydrothermal synthesis, and molecular beam epitaxy. In addition to technical problems, the health and environmental hazards related to nanotube use are becoming more widely recognized. The CNTs, with their fibrous structure similar to asbestos, provide inhalation dangers that can lead to lung disorders such as fibrosis and cancer. ZnO and TiO 2 nanotubes, widely employed in environmental applications, have prompted toxicity concerns, notably addressing their impact on aquatic environments through the formation of reactive oxygen species. These emerging materials, such as GaN, SnO 2 , and TMDs, can pose health and environmental risks due to bioaccumulation and metal ions release. By summarizing existing literature and providing critical insights, we provide the groundwork for future nanotube research and developments.

Ҳали таржима қилинмаган