Active Sites for Adsorption and Reaction of Molecules on Rutile TiO2(110) and Anatase TiO2(001) Surfaces

作者：Tan Shi jing; Wang Bing^*

来源：Chinese Journal of Chemical Physics, 2015, 28(4): 383-395.

DOI：10.1063/1674-0068/28/cjcp1506129

• TiO2
• Rutile
• Anatase
• Photocatalysis
• Scanning tunneling microscopy

The reactivity of specific sites on rutile TiO2(110)-(1x1) surface and anatase TiO2(001)(1x4) surface has been comparably studied by means of high resolution scanning tunneling microscopy. At the rutile TiO2(110)-(1x1) surface, we find the defects of oxygen vacancy provide distinct reactivity for O-2 and CO2 adsorption, while the terminal fivefold-coordinated Ti sites dominate the photocatalytic reactivity for H2O and CH3OH dissociation. At the anatase TiO2(001)-(1x4) surface, the sixfold-coordinated terminal Ti sites at the oxidized surface seem to be inert in both O-2 and H2O reactions, but the Ti-rich defects which introduce the Ti3+ state into the reduced surface are found to provide high reactivity for the reactions of O-2 and H2O. By comparing the reactions on both rutile and anatase surfaces under similar experimental conditions, we find the reactivity of anatase TiO2(001) is actually lower than rutile TiO2(110), which challenges the conventional knowledge that the anatase (001) is the most reactive TiO2 surface. Our findings could provide atomic level insights into the mechanisms of TiO2 based catalytic and photocatalytic chemical reactions.

• 出版日期2015-8
• 单位中国科学技术大学