title: Highly efficient and stable Au/CeO2-TiO2 photocatalyst for nitric oxide abatement: potential application in flue gas treatment.
abstract: In the present work, highly efficient and stable Au/CeO2-TiO2 photocatalysts were prepared by a microwave-assisted solution approach. The Au/CeO2-TiO2 composites with optimal molar ratio of Au/Ce/Ti of 0.004:0.1:1 delivered a remarkably high and stable NO conversion rate of 85% in a continuous flow reactor system under simulated solar light irradiation, which far exceeded the rate of 48% over pure TiO2. The tiny Au nanocrystals (∼1.1 nm) were well stabilized by CeO2 via strong metal-support bonding even it was subjected to calcinations at 550 °C for 6 h. These Au nanocrystals served as the very active sites for activating the molecule of nitric oxide and reducing the transmission time of the photogenerated electrons to accelerate O2 transforming to reactive oxygen species. Moreover, the Au-Ce(3+) interface formed and served as an anchoring site of O2 molecule. Then more adsorbed oxygen could react with photogenerated electrons on TiO2 surfaces to produce more superoxide radicals for NO oxidation, resulting in the improved efficiency. Meanwhile, O2 was also captured at the Au/TiO2 perimeter site and the NO molecules on TiO2 sites were initially delivered to the active perimeter site via diffusion on the TiO2 surface, where they assisted O-O bond dissociation and reacted with oxygen at these perimeter sites. Therefore, these finite Au nanocrystals can consecutively expose active sites for oxidizing NO. These synergistic effects created an efficient and stable system for breaking down NO pollutants. Furthermore, the excellent antisintering property of the catalyst will allow them for the potential application in photocatalytic treatment of high-temperature flue gas from power plant.
authors.affiliation: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Life and Environmental Science, Shanghai Normal University , Shanghai 200234, China (PRC).
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Life and Environmental Science, Shanghai Normal University , Shanghai 200234, China (PRC).
authors.forename: Shuning
authors.initials: S
authors.lastname: Xiao
authors.affiliation: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Life and Environmental Science, Shanghai Normal University , Shanghai 200234, China (PRC).
authors.forename: Dieqing
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Life and Environmental Science, Shanghai Normal University , Shanghai 200234, China (PRC).
authors.forename: Peijue
authors.initials: P
authors.lastname: Liu
authors.affiliation: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Life and Environmental Science, Shanghai Normal University , Shanghai 200234, China (PRC).
authors.forename: Hongjun
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Life and Environmental Science, Shanghai Normal University , Shanghai 200234, China (PRC).
authors.forename: Wenrui
authors.initials: W
authors.lastname: Dai
authors.affiliation: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Life and Environmental Science, Shanghai Normal University , Shanghai 200234, China (PRC).
authors.forename: Fanfan
authors.initials: F
authors.lastname: Liu
authors.affiliation: Key Laboratory of Resource Chemistry of Ministry of Education, Shanghai Key Laboratory of Rare Earth Functional Materials, College of Life and Environmental Science, Shanghai Normal University , Shanghai 200234, China (PRC).
authors.forename: Hexing
authors.initials: H
authors.lastname: Li