MXenes: Structure, properties, and photothermal applications

The ever-growing interest in MXenes has been driven by their unique electrical, thermal, mechanical, and optical properties. Due to the presence of diverse surface ligands and defect sites, MXenes exhibit desirable and highly tunable optical response in the solar spectrum. In addition, they have also been found to be effective shields for electromagnetic interference thanks to their selective electromagnetic wave absorption capability. These features collectively provide MXenes with promising potentials for photothermal conversion applications. However, the underlying scientific mechanisms, pathways, and potential impact of photothermal conversion by MXenes remain poorly categorized and understood. In this review, the electronic, optical, and plasmonic properties and potential photothermal mechanism of MXene materials are systematically summarized. Current advances in various photothermal applications as well as challenges and opportunities in relevant fields are also presented. This review provides comprehensive understandings on the fundamental properties as well as a guidance for in-depth investigation of the photothermal conversion mechanism.