THE ADSORPTION AND PHOTODESORPTION OF OXYGEN ON THE TIO2(110) SURFACE

摘要: We have investigated the adsorption and thermal conversion of molecular oxygen (O2) states on TiO2(110) surface by making use distinct photodesorption behavior each state. Oxygen chemisorbs at vacancy defect sites annealed 105 K to a saturation coverage less than 0.12 monolayers (ML), producing mostly α‐O2 species which is observed undergo slow photodesorption. Upon heating this above 250 K, converted β‐O2 state can photodesorb significantly higher rate. The dissociates 400 produce atomic oxygen, eliminating anionic vacancies. Both α‐ β‐photodesorption processes threshold energy TiO2 band gap (3.1 eV), indicating substrate excitation mediated process. time‐profile fitted with an exponential decay function cross section ∼8×10−17 cm2 for ∼1.5×10−15 photon energy...