Catalysis Communications
journal homepage: www.elsevier.com/locate/catcom
Short Communication
Sonocatalytic performance of AgBr in the degradation of organic dyes in
aqueous solution
a
a,
b, ,1
c,
d, ,1
a
a
Yun Wu , Limin Song ⁎, Shujuan Zhang ⁎ , Xiaoqing Wu ⁎, Shuna Zhang ⁎ , Haifeng Tian , Jiayi Ye
a
College of Environment and Chemical Engineering & State Key Laboratory of Hollow-Fiber Membrane Materials and Membrane Processes, Tianjin Polytechnic University, Tianjin,
3
00387, PR China
b
College of Science, Tianjin University of Science & Technology, Tianjin, 300457, PR China
Institute of Composite Materials & Ministry of Education Key Laboratory of Advanced Textile Composite Materials, Tianjin Polytechnic University, Tianjin, 300387, PR China
Zhejiang Industry Polytechnic College, Shaoxing, 312000, PR China
c
d
a r t i c l e i n f o
a b s t r a c t
Article history:
AgBr sonocatalysts were prepared by a simple method. The AgBr sonocatalysts exhibited excellent sonocatalytic
activities against the decolorization of methylene blue, rhodamine B, and methyl orange. By determining the
content of •OH radicals in the ultrasonic degradation of organic dyes, many •OH radicals were detected, which
may be responsible for the high sonodegradation rate over AgBr under ultrasonic radiation. Based on the effects
of the initial dye concentration on the sonodegradation, we also discussed and analyzed the kinetic data, and the
results are consistent with the first-order kinetic rate equation.
Received 17 January 2013
Received in revised form 21 March 2013
Accepted 21 March 2013
Available online 2 April 2013
Keywords:
AgBr
Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.
Sonocatalysis
Organic dye
1
. Introduction
Over the past few decades, sonocatalytic oxidation has been applied
2. Experimental
2.1. Synthesis of sonocatalysts
in pollution control because it can effectively destroy the molecular
structures of organic pollutants [1–3]. Sonocatalytic oxidation is well
known to be highly efficient, energy-saving, cheap, and free from sec-
ondary pollution [4]. Sonocatalysis is spotlighted because it may solve
contamination problems. Therefore, many potential sonocatalytically
All chemicals were purchased from commercial sources and used
without further purification. According to a previous reference [9],
AgBr sonocatalysts were prepared. Ag
by a precipitate route. 1.94 g Na MoO
2
MoO
and 2.72 g AgNO
4
precursors were prepared
were dissolved
2
4
3
active semiconductors, including TiO
2
and ZnO, have been studied and
in 60 mL of distilled water, respectively. The pH value of the above solu-
tion was adjusted to 8.0 using 0.2 mol/L NaOH solution. The mixture was
poured into a 100 mL teflon-lined stainless autoclave. The autoclave was
allowed to be heated at 180 °C for 1 h, and then cooled to room temper-
reported [5–8]. These semiconductors were of superb sonocatalytic
activities under experimental conditions. However, developing new
highly active sonocatalysts remains challenging. AgBr is more efficient
than TiO
2
in the photocatalytic degradation of organic matter [9,10].
ature in air. The Ag
ethanol and deionized water and dried at 60 °C for 3 h in a vacuum
oven. 1.45 g Ag MoO was added to 33 mL of hydrobromic acid (HBr)
under stirring. After 30 min, the AgBr precipitate was collected, washed
with deionized water and dried at 60 °C for 3 h in a vacuum oven.
2 4
MoO precipitates were collected and washed with
Compared with sonocatalysis and photocatalysis, the oxidation of or-
ganic matter relies on •OH radicals. These mechanisms clearly differ in
the consumed energies in forming •OH radicals. In the present study,
we investigated the sonocatalytic performance of AgBr in the degrada-
tion of methylene blue, rhodamine B, and methyl orange in aqueous
solution. In addition, the sonodegradation mechanism was also investi-
gated by detecting the concentration of •OH radicals under ultrasonic
radiation.
2
4
2.2. Characterization of sonocatalysts
X-ray powder diffraction (XRD) measurements of samples were
carried out on a Rigaku D/max 2500 diffractometer (CuKα irradiation,
λ = 1.5406 Å, 40 kV, 40 mA). The morphology and particle sizes were
detected by a scanning electron microscope (SEM, Hitachi S-4800).
UV–vis absorption spectra were obtained using a UV–vis spectrome-
ter (HP8453). The photoluminescence spectra (PL) of samples were
investigated using a photoluminescence analyzer (Cary Eclipse).
⁎
1
Co-first author.