Effect of particle addition on sonochemical reaction.

Enhancement of chemical reaction with a photocatalyst of titanium dioxide (TiO(2)) by ultrasonic irradiation is studied through the absorbance measurements for liberation of iodine from a KI aqueous solution as an index of oxidation reaction. It is well known as a synergetic effect that the addition of TiO(2) fine particles under UV has an ability to enhance the yield in chemical reaction with OH-radical from hot spot at violent collapse of cavitation bubbles with intense ultrasound. In this study, the absorbance is measured after simultaneous irradiation of ultrasound and UV with the addition of TiO(2) much less than the usual concentration by two orders of content. It is shown that, even in case of quite a little TiO(2) addition where the photocatalytic effect is less, the yield is enhanced obviously in comparison with the summation in yield of independent procedure of ultrasound without TiO(2) and UV with TiO(2). The absorbance-peak deviation to the shorter wavelength implies the generation of titanium peroxide (TiO(3)). The effect of particle addition is due to the chemically activated particle surface on the TiO(2) and probably to the increase in the cavitation bubbles that results in promoting a transfer of OH-radical and other oxidants to bulk liquid region at the collapse.

[1]  T. Tuziuti,et al.  Difference in Threshold between Sono- and Sonochemical Luminescence , 2000 .

[2]  K. Suslick,et al.  Applications of Ultrasound to Materials Chemistry , 1995 .

[3]  K. Yasui,et al.  Single-bubble sonochemiluminescence in aqueous luminol solutions. , 2002, Journal of the American Chemical Society.

[4]  T. Tuziuti,et al.  Measurement of Distribution of Acoustic Radiation Force Perpendicular to Sound Beam Axis , 1999 .

[5]  T. Tuziuti,et al.  Effect of ambient-pressure reduction on multibubble sonochemiluminescence , 2002 .

[6]  Toshio Fukuda,et al.  Control of a Standing Wave Field Using a Line-Focused Transducer for Two-Dimensional Manipulation of Particles , 1998 .

[7]  W. T. Coakley,et al.  Particle column formation in a stationary ultrasonic field , 1992 .

[8]  K. Yasui.  Influence of ultrasonic frequency on multibubble sonoluminescence. , 2002, The Journal of the Acoustical Society of America.

[9]  Linda K. Weavers,et al.  Sonolysis of synthetic sediment particles: particle characteristics affecting particle dissolution and size reduction. , 2002, Ultrasonics sonochemistry.

[10]  T. Leighton.  The Acoustic Bubble , 1994 .

[11]  T. Chopin,et al.  Degradation of phenyltrifluoromethylketone in water by separate or simultaneous use of TiO2 photocatalysis and 30 or 515 kHz ultrasound , 1999 .

[12]  J. Caltagirone,et al.  Spatio-temporal dynamics of cavitation bubble clouds in a low frequency reactor: comparison between theoretical and experimental results. , 2001, Ultrasonics sonochemistry.

[13]  K. Suslick,et al.  Temperature of Multibubble Sonoluminescence in Water , 1999 .

[14]  A. Trotman‐Dickenson,et al.  ‘Comprehensive’ Inorganic Chemistry , 1958, Nature.

[15]  R. Köster,et al.  Influence of particles on sonochemical reactions in aqueous solutions. , 2002, Ultrasonics.

[16]  S. Martin,et al.  Environmental Applications of Semiconductor Photocatalysis , 1995 .

[17]  Shelly L. Miller,et al.  Dosimetry of Room‐Air Germicidal (254 nm) Radiation Using Spherical Actinometry , 1999, Photochemistry and photobiology.

[18]  C. Pirola,et al.  Degradation of organic water pollutants through sonophotocatalysis in the presence of TiO(2). , 2003, Ultrasonics sonochemistry.

[19]  Hideto Mitome,et al.  A standard method to calibrate sonochemical efficiency of an individual reaction system. , 2003, Ultrasonics sonochemistry.

[20]  K. Yasui.  Temperature in multibubble sonoluminescence , 2001 .

[21]  P. Smirniotis,et al.  Sonophotocatalytic destruction of organic contaminants in aqueous systems on TiO2 powders , 2001 .

[22]  H. Sekiguchi,et al.  Effect of Alumina Particles on Sonolysis Degradation of Chlorobenzene in Aqueous Solution , 2001 .

[23]  T. Tuziuti,et al.  Dependence of sonoluminescence intensity on the geometrical configuration of a reactor cell , 2001, IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

[24]  Knud Aage Mørch,et al.  Cavitation inception by almost spherical solid particles in water , 2003 .