Novel MXene-metal–organic framework composites as high-performance adsorbents

Abstract Adsorption has been a useful technology in purification, energy and storage, to name just a few applications. Among adsorbents, two materials have been identified that appear to outperform the rest, namely MXenes and metal–organic frameworks (MOFs). However, both of these seem to have the same shortcoming, i.e. reduced efficiency arising from their tendency to agglomerate and coagulate. Luckily, this is addressed when both are combined into a composite, and the resulting composite can have comparable or superior adsorptive characteristics depending on how they have been tuned for application. They are produced similarly to their constituent parts, where the methodologies are just combined in numerous ways. These composites, as well as their constituent parts, have been used in impregnated 3D printing to create free-standing, self-supported adsorptive structures, which widens their possible applications significantly. Due to the numerous different combinations and configurations of both MXenes and MOFs, the composites have not been thoroughly investigated as adsorbents, especially with varying applications of adsorption currently in use. This mini-review initially focuses on MXenes and MOFs independently before considering possible composites of the two in finer detail. Thereafter, the mini-review concludes by considering the future applications of this technology and what further studies can be undertaken. This review serves as a justification for further investigation into these MXene-metal–organic framework (MXOF) composites as an adsorbent, especially as an adsorbent used for low-volume and low-weight storage of gases or purification of low-concentration, high-value substances.