Non-toxic 2D Ti3C2 MXene surface-modified with Al, Ga, In alkoxides by chemical reactions with metal trialkyls

Understanding the surface chemistry and reactivity of 2D MXenes is of fundamental importance in developing more advanced functional materials. In this work, we describe multilayered Ti3C2 MXene-based materials such as Ti3C2/Al3＋, Ti3C2/In3+ and Ti3C2/Ga3+, obtained by modifying the MXene surface with aluminum-, indium- and gallium alkoxides. In the synthesis of these materials, organometallic compounds of group 13 metals (Et3Al, Me3In, and Et3Ga) were chosen as precursors for the alkoxides to modify the surface. To attach organometallic compounds to the MXene surface, their high reactivity towards the terminal OH, = O and F groups present on the MXene surface was used. In the next step, exposure of the surface-attached aluminum-, indium and gallium alkyls to air allowed their transformation into metal alkoxides due to the high reactivity of the metal-carbon bonds to oxygen and water. In our method of MXene modification, the alkoxide precursors can be extended to other organometallic compounds, such as groups 1, 2 and 12 alkyls. Microbiological studies of the developed 2D Ti3C2/Al3＋, Ti3C2/In3+ and Ti3C2/Ga3+ alkoxides showed no acute ecotoxicity to the tested microorganisms. The obtained materials did not influence bioluminescent/biosensor-type microorganisms nor reduce the viability of other types of microorganisms, such as Staphylococcus aureus, Escherichia coli or Candida albicans. The obtained results clearly indicate that the surface modification of 2D Ti3C2 MXene with group 13 metal compounds is highly prospective toward the development of various types of materials that do not show any adverse effects to living organisms.