Future Prospective and Research Avenues

The holistic evaluation and the breathtaking success of two-dimensional transition metal carbides/nitrides (also known as MXenes), has gained intense momentum by unlocking several new directions toward its usage in multiple applications due to their evolutionary hallmark properties. MXenes quickly led to the exploration and exfoliation from diverse communities, including catalysis, electrochemistry, biomedicine, energy harvesting, sensing, electromagnetic wave shielding/absorption, and so on. Besides technological importance, an in-depth understanding of MXenes is urgently required to elucidate the structure–property-performance inter-relationships. The research community should enable novel applications by making new discoveries of MXenes in different fields. In this direction, the proposed chapter will discuss the major challenges and outlook for future research on MXenes and associated families. The issues related to the synthesis of MXenes, for example, developing safe, efficient, eco-friendly, and scalable synthesis methods and enhancing stability at room temperature will be explored. This includes the design and development of advanced structures, such as mechanically exfoliated MAX phases (MAXenes), vapor-grown 2D nitrides, 2D borides (MBenes), and predicted MC2 2D carbides, which can provide ingredients for future technologies. Due to the large variety of chemical compositions, emerging machine learning approaches should be integrated with the multiscale modeling frameworks to hasten the discovery of unearthed MXenes. It is highly encouraged to develop MXenes with functional groups other than halogens or O, H (such as N, H, Te, Se, S, etc.) to obtain enhanced properties. MXene-based biomedical applications will be elaborated, as they are the replacement of expensive noble metals to enable life-saving medical treatments. High-performing optoelectronic applications require urgent fabrication of advanced MXenes with suitable properties to design transparent electronic devices. Future direction includes the assembly of MXenes with distinct layer structures to advance their applications in light-emitting devices, photodetectors, photovoltaics, barristors, and flexible electronics. Overall, this chapter compiles up the family of MXenes discovered so far and would serve as a good platform to illustrate their terminology in future discoveries.