Synthesis and advanced applications of MXene nanosheets in energy storage, EMI shielding, and biomedicine: a review

Abstract

MXenes, a rapidly expanding family of two-dimensional (2D) transition-metal carbides, nitrides, and carbonitrides, have attracted significant attention for their unique properties, including metallic conductivity, hydrophilicity, and tunable surface chemistry. This review comprehensively examines the synthesis methods of MXenes, focusing on selective etching techniques, such as hydrofluoric acid (HF) etching, and safer alternatives, including in situ HF generation and molten salt etching. The structure–property relationships of MXenes are explored, highlighting their exceptional electrical conductivity, mechanical strength, and surface chemistry, all of which are pivotal to their performance in various applications. Key applications discussed include energy storage (supercapacitors and batteries), where MXenes exhibit high capacitance and efficient ion intercalation; electromagnetic interference (EMI) shielding, leveraging their conductivity and layered structure for superior attenuation; and biomedical uses, such as drug delivery and biosensing, enabled by their biocompatibility and functionalization potential. Despite their promise, challenges such as environmental stability and scalable synthesis persist, necessitating further research to fully realize their potential in next-generation technologies. This review consolidates current knowledge, identifies critical challenges, and outlines future directions for MXene research and applications.