Visible-Light-Induced Photocatalytic Degradation of Azodyes in Aqueous AgI/TiO₂ Dispersion

Abstract

AgI/TiO2 was prepared by the deposition−precipitation method and was found to be a novel visible light driven photocatalyst. The catalyst showed high efficiency for the degradation of the nonbiodegradable azodyes reactive red K-2G, reactive brilliant red X-3B, reactive red K-2BP, and reactive yellow KD-3G under visible light irradiation (λ > 420 nm). The catalyst's activity was maintained effectively after successive cyclic experiments under visible irradiation without the destruction of AgI. On the basis of the characterization of X-ray diffraction, X-ray photoelectron spectroscopy, and Auger electron spectroscopy, the structure of AgI loaded on TiO2 did not significantly change before and after reaction. K-2G was completely decolorized and partly mineralized. The main intermediates are the small organic acids besides CO2 and cyanuric acid, which is photostable. The •OH is the main active oxygen species in the photocatalytic reaction by the studies of electron spin resonance and the effect of radical scavengers.

Photocatalytic Degradation of Pathogenic Bacteria with AgI/TiO2 under Visible Light Irradiation

“…21 Furthermore, in the visible light irradiated AgI/ TiO 2 system, the formation of H 2 O 2 also was detected as shown in the previous work. 15 The results indicated that • OH and H 2 O 2 reactive species were involved in the photocatalytic bactericidal reaction. S. aureus was also killed efficiently in aqueous AgI/ TiO 2 suspensions under visible light irradiation.…”

“…15 In the present study, the photocatalytic inactivation of the pathogenic bacteria Escherichia coli and Staphylococcus aureus in an aqueous AgI/TiO 2 suspension under visible light irradiation was systematically studied from the mechanistic and kinetic viewpoints. The details of photocatalytic degradation of the cell wall and the cell membrane were characterized by TEM and FT-IR measurements.…”

Regulations of silver halide nanostructure and composites on photocatalysis

“…Maybe it was the first time to confessedly recognize the silver halide as photocatalyst. In 2006, a visible-light-induced photocatalyst AgI/TiO 2 was prepared by Chun Hu et al and was found to show high efficiency for the degradation of azodyes, which based on their previous work visible-light-driven photocatalyst AgBr/TiO 2 [115]. The above-mentioned is primary regarding the origin of silver halides on the photocatalysis application.…”

“…The above-mentioned is primary regarding the origin of silver halides on the photocatalysis application. From then on, tremendous works with respect to the property and morphology modification on silver halides sprang up to advance their photocatalytic performance [114][115][116][117][118][119][120][121].…”

Microwave-assisted preparation of photoactive TiO2 on textile substrates

“…[11][12][13][14][15][16][17] In particular, the treatment of wastewater from textile dyeing processes containing reactive dye stuffs should be mentioned. 18,19 For those applications, it is possible to use TiO 2 as a powder. However, for many applications it is more suitable to have the TiO 2 as a kind of photoactive coating on a substrate, which can be easily introduced into the application process and removed after the process is finished.…”