Surface Structures of Fe-TiO2 Photocatalysts for NO Oxidation

Commercial rutile TiO2 particles capped with Al2O3 and ZrO2 layers, which are widely used in white pigments, can serve as a starting material for the fabrication of visible lightresponsive photocatalysts toward gas-phase NO oxidation. The asreceived TiO2 with iron impurities exhibited reduced photocatalytic activity, and the activity was boosted by the deposition of additional iron comparable in quantity to the intrinsic iron impurity level. Analyses using X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectroscopy, and low-energy ion scattering spectroscopy revealed that the deposited iron and intrinsic impurity iron are dissimilar in terms of location, oxidation states, and interaction with TiO2. This suggests that tracking the structure and impurity levels of photocatalyst elements can be crucial for understanding structure-activity relationships of real catalysts.

Automated summary

Commercial rutile TiO2 particles capped with Al2O3 and ZrO2 layers were used as a starting material for visible light-responsive gas-phase NO oxidation photocatalysts. The study found that the photocatalytic activity of TiO2 with iron impurities was improved by the deposition of additional iron comparable to the intrinsic iron impurity level. Analysis using various spectroscopy techniques revealed differences in location, oxidation states, and interaction with TiO2 between the deposited iron and intrinsic impurity iron.