Adsorption Activities of O, OH, F and Au on Two-Dimensional Ti2C and Ti3C2 Surfaces

Two-dimensional Ti2C and Ti3C2 structures are highly stable and have high specific surface areas, and therefore represent promising materials with potential applications as carriers in transition metal catalysis, Li-ion batteries, and hydrogen storage devices. It was envisaged that investigating the surface adsorption activities of Ti2C and Ti3C2 would provide useful information about their surface properties. The results of a first-principles study showed that the adsorption energies of OH, O, and F on Ti2C and Ti3C2 surfaces were quite high. By comparing the electronic properties of Ti2C, Ti3C2, Ti(001), and TiC(001), we found that the un-polarized Ti-3d orbitals were responsible for the high surface adsorption activities of these materials. The high surface adsorption activities of the Ti2C and Ti3C2 materials caused them to be terminated with 0, F, and OH surface groups. The surface adsorption energies of the Au particles on the Ti2CO2-2x(OH)(2x) and Ti3C2O2-2x(OH)(2x)) surfaces increase as the ratio of OH increased.