2s and 2p X-ray photoelectron spectra of Ti4+ ion in TiO2

A detailed experimental study of the 2s- and 2p XPS spectra of TiO₂ revealed new (charge-transfer) shake-up satellite structures (at 4.0–5.0 eV from the main peaks) which can be explained using molecular orbital representation. The satellite peaks, situated at about 26 eV from the main peaks, the origin of which was in doubt in the previously reported works are shown conclusively in the present investigation to be energy loss peaks. The relative energies and intensities of the observed satellites are presented and the theoretical implications of the work are discussed.