The electrodeless discharge lamp: a prospective tool for photochemistry

Klán, Petr; Literák, Jaromı́r; Hájek, Milan

doi:10.1016/s1010-6030(99)00165-3

Cited by 59 publications

(24 citation statements)

References 23 publications

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“…Microwave energy has exhibited its great ability to accelerate reactions and to improve yields and selectivity on synthetic organic chemistry [2]. Recently, microwave irradiation has been used to assist photochemical reactions in the degradation of organic pollutants [3][4][5][6][7][8][9][10]. The results of these experiments showed that microwave irradiation could considerably accelerate the photodegradation of organic pollutants.…”

Section: Introductionmentioning

confidence: 99%

Investigation of the roles of active oxygen species in photodegradation of azo dye AO7 in TiO2 photocatalysis illuminated by microwave electrodeless lamp

Zhang

Sun

et al. 2008

Journal of Photochemistry and Photobiology A: Chemistry

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a b s t r a c tA novel microwave electrodeless lamp (MWL) was used as the light source for microwave assisted TiO 2 photocatalysis to degrade azo dye Acid Orange 7 (AO7). This technique aims to provide a new way to study the synergetic effect of both UV-vis light and microwave irradiations on aqueous solution of catalysts. The roles of active oxygen species in the photodegradation of AO7, such as hydroxyl radical (HO • ), positive holes (h + ) and hydrogen peroxide (H 2 O 2 ), were investigated to understand the photodegradation mechanism. The presence and roles of these oxidative species were examined using appropriate quenchers. It was found that the degradation of AO7 proceeded via three pathways, namely, UV-induced photocatalytic degradation, visible light-induced dye self-photosensitized degradation and direct photolytic degradation. The percentages of dye degradation by the three pathways were about 31.1%, 39.0% and 19.5%, respectively.

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Section: Introductionmentioning

confidence: 99%

Investigation of the roles of active oxygen species in photodegradation of azo dye AO7 in TiO2 photocatalysis illuminated by microwave electrodeless lamp

Zhang

Sun

et al. 2008

Journal of Photochemistry and Photobiology A: Chemistry

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“…Comparative experiments with conventional mercury lamps showed the higher efficiency of microwave electrodeless lamps providing a high yield of product in a shorter reaction time. Klán et al [13] also confirmed that MWL could feasibly be used in light-induced photofragmentation reaction valerophenone. Horihoshi et al [14] found that an MWL was more effective in microwave-assisted photocatalytic degradation of 2,4-dichlorophenoxyacetic acid than an electrode Hg lamp.…”

Section: E-mail Address: Xiwangzhang@126com (X Zhang)mentioning

confidence: 88%

Oxidative decomposition of azo dye C.I. Acid Orange 7 (AO7) under microwave electrodeless lamp irradiation in the presence of H2O2

Zhang

Wang

et al. 2006

Journal of Hazardous Materials

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A novel microwave electrodeless lamp (MWL) rather than traditional electrode lamp (TEL) was used in a H 2 O 2 /MWL system as light source. This technique provided a new way to study the simultaneous effect of both UV-vis light and microwave irradiations. This study showed that H 2 O 2 /MWL process was 32% more effective than H 2 O 2 /TEL process in degrading azo dye Acid Orange 7 (AO7). Further study found that the degradation of AO7 by the H 2 O 2 /MWL process was initiated by the attack of HO• radicals generated by the photolysis of H 2 O 2 . However, the direct photolysis of AO7 by MWL irradiation was not negligible. Effect of operation parameters, such as the initial concentrations of AO7 and H 2 O 2 and pH, were investigated. A kinetic model of degradation of AO7 by H 2 O 2 /MWL process was found, in which not only the HO• oxidation but also direct photolysis were considered. The kinetic model was consistent with the experiment results. The degradation of AO7 by H 2 O 2 /MWL corresponded to a pseudo-first order reaction. The apparent reaction constant (k ap ) was a function of initial concentrations of H 2 O 2 and AO7 and pH of the solution.

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“…When the MWL is placed in a microwave energy field, the gases within the envelope ionize, a low-pressure plasma discharge forms, heating and beating the envelope, vaporizing materials to emit light. MWL has some unique advantages such as, good photochemical efficiency, long life, low cost, and simple photocatalytic equipment [11,12]. The light intensity can be adjusted by variations in MW power level and irradiation wavelengths can be adjusted by the changes in ratio and nature of the gases in MWL [5].…”

Section: Introductionmentioning

confidence: 99%

Microwave assisted photocatalytic degradation of high concentration azo dye Reactive Brilliant Red X-3B with microwave electrodeless lamp as light source

Zhang

Wang

2007

Dyes and Pigments

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The electrodeless discharge lamp: a prospective tool for photochemistry

Cited by 59 publications

References 23 publications

Investigation of the roles of active oxygen species in photodegradation of azo dye AO7 in TiO2 photocatalysis illuminated by microwave electrodeless lamp

Investigation of the roles of active oxygen species in photodegradation of azo dye AO7 in TiO2 photocatalysis illuminated by microwave electrodeless lamp

Oxidative decomposition of azo dye C.I. Acid Orange 7 (AO7) under microwave electrodeless lamp irradiation in the presence of H2O2

Microwave assisted photocatalytic degradation of high concentration azo dye Reactive Brilliant Red X-3B with microwave electrodeless lamp as light source

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