Plasmon-Induced Photodegradation of Toxic Pollutants with Ag−AgI/Al2O3 under Visible-Light Irradiation

• Published in: Journal of the American Chemical Society 2010-01, Vol.132 (2), p.857-862
• Main Authors: Hu, Chun, Peng, Tianwei, Hu, Xuexiang, Nie, Yulun, Zhou, Xuefeng, Qu, Jiuhui, He, Hong
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja907792d

A plasmonic photocatalyst Ag−AgI supported on mesoporous alumina (Ag−AgI/Al2O3) was prepared by deposition−precipitation and photoreduction methods. The catalyst showed high and stable photocatalytic activity for the degradation and mineralization of toxic persistent organic pollutants, as demonstrated with 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP), and trichlorophenol (TCP) under visible light or simulated solar light irradiation. On the basis of electron spin resonance, cyclic voltammetry analyses under a variety of experimental conditions, two electron transfer processes were verified from the excited Ag NPs to AgI and from 2-CP to the Ag NPs, and the main active species of O2 •− and excited h+ on Ag NPs were involved in the photoreaction system of Ag−AgI/Al2O3. A plasmon-induced photocatalytic mechanism was proposed. Accordingly, the plasmon-induced electron transfer processes elucidated the photostability of Ag−AgI/Al2O3. This finding indicates that the high photosensitivity of noble metal NPs due to surface plasmon resonance could be applied toward the development of new plasmonic visible-light-sensitive photocatalysts and photovoltaic fuel cells.