Effect of the TiCT (T = O, OH, and H) Functionalization on the Formation of (TiO)/TiCT Composites.

First-principles density functional theory calculations are carried out on the (TiO) cluster supported on the TiCT (0001) surface with different chemical terminations, , -H, -O, and -OH, to study the interaction and understand the TiCT functionalization effect on the formation of (TiO)/TiCT composites. Results show an exothermic interaction for all cases, whose strength is driven by the surface termination, promoting weaker bonds when the MXene is functionalized with H atoms. For TiCH and TiC(OH) MXenes, the interaction is accompanied by a charge transfer towards the titania cluster. All adsorptions are accompanied by a significant structural deformation of the titania nanocluster. The analysis of the density of states of (TiO)/TiCH and (TiO)/TiC(OH) composites shows a clear almost metallic character with titania-related states close to the Fermi level. However, for (TiO)/TiCO, the band positions are similar to those of a Type-I heterojunction. Overall, the MXene surface termination influence on the TiO/MXene interaction is unveiled, providing more stable composite formations when the MXene surface is functionalized with -H and -OH groups, where the adsorption process is accompanied by significant charge transfer.