Carbon nanotubes, specifically double-walled ones, are widely used in electronics due to their excellent electrical conductivity and mechanical strength. They are integrated into transistors, sensors, and conductive films to enhance performance and durability. In energy storage, they serve as key components in lithium-ion batteries and supercapacitors, improving energy density and charge-discharge cycles. Their high surface area and thermal conductivity make them ideal for use in composite materials, where they reinforce polymers, metals, and ceramics for aerospace, automotive, and sports equipment. Additionally, they are employed in biomedical applications, such as drug delivery systems and imaging agents, due to their ability to penetrate cells and carry therapeutic payloads. Their unique properties also make them valuable in environmental applications, including water filtration and pollutant detection.