Shielding 2D MXenes against oxidative degradation: recent advances, factors and preventive measures

Abstract

MXenes, a distinctive category of 2D materials predominantly composed of transition metal carbides and nitrides, have gained recognition for their versatile applications. However, their susceptibility to oxidation under ambient conditions hampers their practical utility, necessitating the development of oxidation-resistant MXenes. To attain this objective, a comprehensive understanding of MXene oxidation is needed. This review systematically addresses various factors influencing MXene oxidation, including water/moisture, oxygen, storage and processing conditions, defects, temperature, pH, etc. The elucidation extends to the impact of MXene flake size, concentration, surface terminations, and oxidation across diverse environmental conditions. Additionally, this review delves into the controlled oxidation of MXenes. Exploring strategies for inhibiting MXene oxidation, this review covers preventive measures, including implementation of protective coatings, surface modifications, storage in organic solvents/antioxidants, production of hybrid structures, use of ionic liquids, etc. These approaches provide robust barriers, impeding the diffusion of oxygen and water molecules, thereby substantially prolonging the lifespan and ensuring the performance stability of MXenes. Moreover, these oxidation-resistant strategies not only fortify resistance but also pave the way for tailoring MXene applications. This review explores current challenges and opportunities in developing oxidation-resistant MXenes and outlines future prospects, aiming to advance understanding of MXene oxidation and contribute to the creation of durable MXene-based materials for diverse applications.