Abstract
First-principles density functional theory calculations are carried out on the (TiO(2))(5) cluster supported on the Ti(2)CT (x) (0001) surface with different chemical terminations, i.e., -H, -O, and -OH, to study the interaction and understand the Ti(2)CT (x) functionalization effect on the formation of (TiO(2))(5)/Ti(2)CT (x) 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 Ti(2)CH(2) and Ti(2)C(OH)(2) 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(2))(5)/Ti(2)CH(2) and (TiO(2))(5)/Ti(2)C(OH)(2) composites shows a clear almost metallic character with titania-related states close to the Fermi level. However, for (TiO(2))(5)/Ti(2)CO(2), the band positions are similar to those of a Type-I heterojunction. Overall, the MXene surface termination influence on the TiO(2)/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.