Figure 4.

(a and b) EELS spectra showing the Ti_L_2,3 and O_K edges, acquired from the ALD titania on SLG after 20 cycles at 60 °C, 20 cycles at 200 °C, and 180 cycles at 60 °C and after in situ annealing at 400 °C, respectively. The dashed lines in panel a denote the ∼1 eV energy shift due to different oxidation states of Ti. (c and d) Molecular orbitals for anatase TiO₂ and rocksalt TiO (adapted from ref (23)), together with their unit cell of the crystal lattice. The main difference is the occupancy of the 2t_2g (π*) state, which explains the edge features in the EELS spectra.