Carbon-Based Nanomaterials and Their Green Energy Applications: Carbon Nanotubes

Abstract

In today’s world, the rapid exhaustion of non-renewable energy sources has led to a significant surge in renewable and green energy alternatives. Electrochemical devices are considered to be one of the reliable alternatives. Carbon-based nanostructures, including graphene, carbon nanotubes (CNTs), and similar materials have drawn substantial interest owing to their distinct physicochemical and electrical properties, which render them promising candidates for green energy applications. With the first finding of CNTs by Iijima in 1991, they are exploited in many fields. CNTs are the one-dimensional allotrope of carbon, possessing long hollow tube-like structures made up of sp2carbon having a diameter of nanoscale range and length in micrometers. On the basis of the number of tubes in their structure, they can be either single-or multi-walled CNTs (SWCNTs and MWCNTs, respectively). They have grabbed the interest of researchers owing to their unique chemical composition and many alluring properties like high conductivity, huge mechanical strength, and large surface area. Numerous carbon-based nanomaterials exhibit fascinating structure-property relationships, but it is the CNTs that have garnered the most intense research focus. Owing to such unique properties, CNTs have been utilized either directly as the electrode material or as a support in almost all the fields of electrochemistry: be it sensing, energy conversion, or energy storage applications. CNTs have demonstrated promising results in enhancing the proficiency of energy conversion and storage strategies, thereby contributing to the advancement of green energy innovations. In this chapter, the synthesis, characterization, and unique properties of CNTs are delved. Moreover, its vital role in various green energy applications, specifically in the areas of oxygen electrocatalysis and supercapacitors, is comprehensively discussed. © 2025 by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.