Strategies to modulate the performance of MXenes in energy applications

MXenes, an expanding family of two-dimensional transition metal carbides, nitrides, and carbonitrides, have attracted significant interest owing to their tunable structures and versatile properties. This review systematically outlines advances in MXene research, beginning with an overview of their structural characteristics and classification. It then tracks the evolution of synthesis techniques, from early etching methods to recent fluorine-free routes, accompanied with the evaluation of each approach against key metrics such as safety, scalability, universality, and product quality. The electronic, mechanical, optical, and thermal properties of MXenes are analyzed to elucidate their underlying mechanisms and potential applications. Key tuning strategies, including surface functionalization, single-atom decoration, heterostructure construction, and strain engineering, are critically assessed for enhancing MXene performance in energy-related fields. Applications in catalysis, batteries, and supercapacitors are comprehensively surveyed to bridge material design with electrochemical behavior. Finally, forward-looking perspectives are offered, covering the development of novel MXenes, optimized fluorine-free synthesis, stability studies, innovative tuning strategies, application expansion, and the guiding role of theoretical computations. This review aims to provide a structured and insightful reference for advancing MXene-based sustainable energy technologies.