Double-walled carbon nanotubes are widely used in electronics due to their exceptional electrical conductivity and mechanical strength. They are incorporated 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 charge capacity and efficiency. Their high surface area and thermal conductivity make them ideal for use in composite materials, which are applied in aerospace and automotive industries to create lightweight yet strong structures. Additionally, they are utilized in biomedical applications, such as drug delivery systems and imaging agents, due to their ability to penetrate cells and tissues effectively. Their unique properties also enable their use in environmental applications, including water filtration and pollutant removal, where they act as efficient adsorbents.