Green and Antioxidant-Functionalized MXenes: Progress, Challenges, and Applications

MXenes are a family of two-dimensional transition metal carbides and nitrides (Mn+1XnTx) that exhibit high electrical conductivity, large surface area, and surface hydrophilicity, making them promising candidates for applications in energy storage, sensors, biomedical devices, and smart textiles. However, their synthesis commonly relies on high-level etching agents such as hydrofluoric acid (HF), raising significant concerns regarding safety and environmental sustainability. This has driven growing interest in developing green synthesis approaches that minimize toxic by-products and operational risks. Despite their functional advantages across diverse applications, MXenes face a major limitation in the form of rapid oxidation, particularly in aqueous or ambient conditions, which severely affects their durability. Surface modification using natural antioxidants, such as plant-derived polyphenols, flavonoids, and organic acids, has emerged as a green and effective strategy to enhance oxidative stability while improving biocompatibility. This review provides an overview of the current progress in green synthesis methods and antioxidant-based surface functionalization of MXenes. It also provides an overview of the potential of MXenes across diverse application domains.