Present status and prospects of MXene research

Abstract

The MXene family has turned the tables in the materials field since its first reported work in 2011. This is primarily because of the unique underlying physical and chemical properties of these 2D nanomaterial. High metallic conductivity and greater robustness provided by MXene sheets have already given them a leading edge over transition metal dichalcogenides and graphite. The MXene family has now entered into a vast platform of sensor applications, wherein they are acting as a quintessential element. Incorporating MXene flakes above the metal substrates provides stronger corrosion protection, a large surface area, and increased hydrophilicity. Due to its stability in aqueous solutions, it is an active co-catalyst that captures the photo-generated charges utilized for sustainable hydrogen production. The most commonly used MXene, i.e., Ti3C2Tx, is reported to exhibit intense plasmonic behavior in the near to mid-infrared region. Strongly tunable optical properties of Ti3C2Tx, Nb2C, and Ta2C have also emerged as promising SERS substrates. The excellent mechanical strength and flexibility exhibited by crumpled MXene hybrid nano-coatings strive to act as electrodes, which were acquired for designing bendable high-performance supercapacitors. MXene films provide non-toxicity and hydrophilicity towards miniscule organisms, making them biologically compatible. By tailoring the properties using different MXene geometrical configurations (films, nanostructures, or 3D network layered structure), a plethora of applications in different domains are coming up. These applications also depend on the type of terminated groups utilized; for example, the –OH terminated groups have the strongest binding energy strength compared to their counterparts. So far, with over 30 MXene stoichiometric varieties reported, the future holds promising prospects of incorporating the MXene family into myriad real-world applications. The challenge lies in the experimental validation/realization of more and more MXene composites and the possibility of tweaking their intrinsic properties for large-scale commercial production. Therefore, the chapter attempts to gather the current state-of-the-art research carried out over the past few years to unravel the exquisite features of the MXene family and its composites. Consequently, the chapter will attempt to thoroughly analyze the present situation and future opportunities facing the MXene family in creating effective and long-lasting composites.