Advances in solvent-free microwave synthesis of carbon and carbon/metal composite nanomaterials for electrocatalytic applications

Abstract

Carbon-based nanocomposites are known as cost-effective, high-performance electrocatalysts with broad applications in electrochemical energy conversion. However, the process of synthesizing carbon-based nanomaterials by traditional methods is both energy consuming and time consuming. As a new field, solvent-free microwave (SFMW) technology has emerged as a promising alternative, with its groundbreaking significance lying in the ability to achieve rapid heating of localized areas up to 1000 °C within one minute, while effectively suppressing side reactions through the application of high-intensity microwave fields. This provides a rapid, efficient, and environmentally friendly approach for nanomaterial synthesis. The strong interaction between carbon materials and microwave radiation enables localized and rapid heating, accelerating reaction kinetics and facilitating the formation of unique nanostructures. This review highlights recent advances in the SFMW synthesis of carbon nanomaterials, including graphene and carbon nanotubes, as well as carbon/metal composites such as carbon-supported single atoms, metal nanoparticles, alloys, high-entropy alloys, and metal compounds. The fundamental principles of solvent-free microwave heating are introduced, and the electrocatalytic applications of these materials are comprehensively discussed. Finally, the current challenges and future prospects of SFMW technology in the scalable production and practical implementation of advanced electrocatalysts are discussed.