Advancement in nanocarbon-based thermoelectric materials: surface modification strategies, efficiency analysis, and applications

Abstract

The global dependence on energy-intensive systems inevitably leads to substantial amounts of heat dissipation into the environment, predominantly as low-grade waste heat below 100 °C. Conventional recovery methods often struggle to effectively harness this dispersed thermal energy. Thermoelectric (TE) materials, which can directly convert temperature gradients into electrical energy, present a promising solution for reclaiming low-temperature waste heat. However, limited conversion efficiency and material performance currently hinder their widespread application. Recent advancements in nanocarbon integration into TE systems offer a significant breakthrough. Nanocarbons, such as graphene, carbon nanotubes (CNTs), and their derivatives, exhibit exceptional electrical conductivity, thermal tunability, and mechanical resilience, making them ideal candidates for enhancing TE performance. The degree of enhancement, however, is critically dependent on precise synthesis routes, structural control, and characterization of morphological defects. This review examines carbon-based TE materials, focusing on their synthesis strategies, structural evolution, and physical properties. Emphasis is placed on surface modification techniques and defect engineering approaches that optimize TE parameters such as the Seebeck coefficient, electrical conductivity, and thermal conductivity. Furthermore, the review examines the potential applications of these materials in sustainable energy conversion, self-powered sensors, and wearable electronics. By bridging the gap between nanoscale material design and practical application, this article underscores the transformative potential of carbon-based TEs in addressing global energy inefficiencies, offering a viable path toward sustainable power generation and next-generation technologies.