Structure and absorption properties of the C212 dye chemisorbed onto the TiO2 (1Â 0Â 1) anatase surface

► The main absorption band of C212 is blue shifted upon absorption on the TiO2 surface. ► The blue shift partly originates from the deprotonation of the carboxylic acid group. ► The combination of the SCC-DFTB and TD-DFT methods reproduces well the experiments.