Hollow tubes constructed by carbon nanotubes self-assembly for CO₂ capture

Carbon nanotubes (CNTs) have garnered significant attention in the fields of science, engineering, and medicine due to their numerous advantages. The initial step towards harnessing the potential of CNTs involves their macroscopic assembly. The present study employed a gentle and direct self-assembly technique, wherein controlled growth of CNT sheaths occurred on the metal wire’s surface, followed by etching of the remaining metal to obtain the hollow tubes composed of CNTs. By controlling the growth time and temperature, it is possible to alter the thickness of the CNTs sheath. After immersing in a solution containing 1 g/L of CNTs at 60 °C for 24 h, the resulting CNTs layer achieved a thickness of up to 60 µm. These hollow CNTs tubes with varying inner diameters were prepared through surface reinforcement using polymers and sacrificing metal wires, thereby exhibiting exceptional attributes such as robustness, flexibility, air tightness, and high adsorption capacity that effectively capture CO₂ from the gas mixture.