Carboxylic multi-walled carbon nanotubes are widely used in various advanced applications due to their unique properties. In the field of electronics, they serve as conductive additives in composites, enhancing the electrical conductivity of materials used in batteries, supercapacitors, and sensors. Their high surface area and functional groups make them ideal for use in energy storage devices, where they improve charge storage and transfer efficiency. In biomedical applications, these nanotubes are employed for drug delivery systems, where their functionalized surface allows for the attachment of therapeutic agents, enabling targeted delivery to specific cells or tissues. They are also used in biosensors for detecting biomarkers, owing to their sensitivity and ability to facilitate electron transfer. In environmental applications, carboxylic multi-walled carbon nanotubes are utilized in water purification processes. Their functional groups enable the adsorption of heavy metals and organic pollutants, making them effective in filtration systems. Additionally, they are incorporated into polymer composites to enhance mechanical strength and thermal stability, making them suitable for use in aerospace, automotive, and construction industries.