Enhanced Photodegradation of Toxic Pollutants on Plasmonic Au–Ag–AgI/Al2O3 Under Visible Irradiation

• Published in: Catalysis letters 2012-05, Vol.142 (5), p.646-654
• Main Authors: Peng, Tianwei, Hu, Chun, Hu, Xuexiang, Zhou, Xuefeng, Qu, Jiuhui
• Format: Article
• Language: English
• Subjects: Aluminum oxide; Bimetals; Catalysis; Catalysts; Catalytic activity; Chemistry; Chemistry and Materials Science; Colloidal state and disperse state; Dispersion; Electron paramagnetic resonance; Electron spin; Electron transfer; Electrons; Energy conversion efficiency; Exact sciences and technology; General and physical chemistry; Gold; Industrial Chemistry/Chemical Engineering; Irradiation; Nanoparticles; Organometallic Chemistry; Photocatalysis; Photochemistry; Photodegradation; Photosensitivity; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physical Chemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Pollutants; Porous materials; Silver; Spin resonance; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1011-372X; 1572-879X
• DOI: 10.1007/s10562-012-0788-2

Au–Ag–AgI nanoparticles (NPs) were uniformly dispersed onto mesoporous alumina by deposition–precipitation and photoreduction at low temperature. Compared with Ag–AgI/Al 2 O 3 , the catalyst showed higher photocatalytic activity under visible irradiation. In particular, the release of metal ions from the catalyst was significantly inhibited during photodegradation of pollutants. Electron spin resonance and cyclic voltammograms studies under a variety of experimental conditions verified that the coupling of Au and Ag NPs increased the efficiency of light energy conversion and accelerated interfacial electron transfer processes. The main active species involved in the photoreaction of Au–Ag–AgI/Al 2 O 3 were O 2 •− and excited h + on the metal NPs. The presence of several ubiquitous anions, including HCO 3 − , SO 4 2− , and NO 3 − could act as electron donors trapping excited h + on the metal NPs to facilitate electron circulation. The results obtained herein indicated that coupled, noble, bimetal NPs exhibited high photosensitivity and photostability due to enhanced surface plasmon resonance and interfacial electron transfer. Graphical Abstract Addition of Au made Au–Ag–AgI nanoparticles (NPs) disperse more uniformly onto mesoporous Al 2 O 3 and showed higher photocatalytic activity under visible irradiation.