Direct Detection of OH Radicals Diffused to the Gas Phase from the UV-Irradiated Photocatalytic TiO2Surfaces by Means of Laser-Induced Fluorescence Spectroscopy

2006 ◽  
Vol 110 (34) ◽  
pp. 16808-16811 ◽  
Author(s):  
Yoshinori Murakami ◽  
Endo Kenji ◽  
Atsuko Y. Nosaka ◽  
Yoshio Nosaka
Keyword(s):  
Fluorescence Spectroscopy ◽  
Gas Phase ◽  
Direct Detection ◽  
Laser Induced Fluorescence ◽  
Oh Radicals

scholarly journals Measurements of OH and HO<sub>2</sub> yields from the gas phase ozonolysis of isoprene

2010 ◽  
Vol 10 (3) ◽  
pp. 1441-1459 ◽  
Author(s):  
T. L. Malkin ◽  
A. Goddard ◽  
D. E. Heard ◽  
P. W. Seakins
Keyword(s):  
Gas Phase ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Recent Literature ◽  
Direct Detection ◽  
Kinetic Method ◽  
Oh Radicals ◽  
First Order ◽  
Gas Expansion ◽  
First Time

Abstract. The reactions of ozone with alkenes are an important source of hydroxyl (OH) radicals; however, quantification of their importance is hindered by uncertainties in the absolute OH yield. Hydroxyl radical yields for the gas-phase ozonolysis of isoprene are determined in this paper by four different methods: (1) The use of cyclohexane as an OH scavenger, and the production of cyclohexanone, (2) The use of 1,3,5-trimethylbenzene as an OH tracer, and the diminution in its concentration, (3) A kinetic method in which the OH yield was obtained by performing a series of pseudo-first-order experiments in the presence or absence of an OH scavenger (cyclohexane), (4) The OH and HO2 yields were determined by fitting the temporal OH and HO2 profiles following direct detection of absolute OH and HO2 concentrations by laser induced fluorescence at low pressure (Fluorescence Assay by Gas Expansion- FAGE). The following OH yields for the ozonolysis of isoprene were obtained, relative to alkene consumed, for each method: (1) Scavenger (0.25±0.04), (2) Tracer (0.25±0.03), (3) Kinetic study (0.27±0.02), and (4) Direct observation (0.26±0.02), the error being one standard deviation. An averaged OH yield of 0.26±0.02 is recommended at room temperature and atmospheric pressure and this result is compared with recent literature determinations. The HO2 yield was directly determined for the first time using FAGE to be 0.26±0.03.

The measurement of tropospheric OH radicals by laser-induced fluorescence spectroscopy during the POPCORN Field Campaign

1996 ◽  
Vol 23 (18) ◽  
pp. 2541-2544 ◽  
Author(s):  
A. Hofzumahaus ◽  
U. Aschmutat ◽  
M. Heßling ◽  
F. Holland ◽  
D. H. Ehhalt
Keyword(s):  
Fluorescence Spectroscopy ◽  
Laser Induced Fluorescence ◽  
Oh Radicals ◽  
Field Campaign

Direct Detection of OH Radicals and Indirect Detection of H2O2 Molecules in the Gas Phase near a TiO2 Photocatalyst Using LIF

2008 ◽  
Vol 112 (25) ◽  
pp. 9115-9119 ◽  
Author(s):  
Guillaume Vincent ◽  
Alina Aluculesei ◽  
Alexander Parker ◽  
Christa Fittschen ◽  
Orfan Zahraa ◽  
...  
Keyword(s):  
Gas Phase ◽  
Direct Detection ◽  
Indirect Detection ◽  
Oh Radicals ◽  
Tio2 Photocatalyst
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