Visible light-induced photocatalytic degradation of Acid Orange 7 in aqueous TiO2 suspensions

Stylidi, Maria; Kondarides, Dimitris Ι.; Verykios, Xenophon E.

doi:10.1016/j.apcatb.2003.09.014

Cited by 618 publications

(240 citation statements)

References 38 publications

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“…The vibration at 1453 cm À1 is related to N@N stretching. The bands at 1255 and 1205 cm À1 are assigned to m(C-N) and m(N-N) stretching vibrations, and the peaks at 1123 and 1037 cm À1 are due to the coupling between the benzene mode and ms(SO 3 ) (Bandara et al, 1999;Stylidi et al, 2003Stylidi et al, , 2004Zhang et al, 2005).…”

Section: Ftir Spectra For Ao7 On the Composite And Its Catalytic Degrmentioning

confidence: 99%

CuFe2O4/activated carbon composite: A novel magnetic adsorbent for the removal of acid orange II and catalytic regeneration

et al. 2007

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CuFe 2 O 4 /activated carbon magnetic adsorbents, which combined the adsorption features of activated carbon with the magnetic and the excellent catalytic properties of powdered CuFe 2 O 4 , were developed using a simple chemical coprecipitation procedure. The prepared magnetic composites can be used to adsorb acid orange II (AO7) in water and subsequently, easily be separated from the medium by a magnetic technique. CuFe 2 O 4 /activated carbon magnetic adsorbents with mass ratio of 1:1, 1:1.5 and 1:2 were prepared. Magnetization measurements, BET surface area measurements, powder XRD and SEM were used to characterize the prepared adsorbents. The results indicate that the magnetic phase present is spinel copper ferrite and the presence of CuFe 2 O 4 did not significantly affect the surface area and pore structure of the activated carbon. The adsorption kinetics and adsorption isotherm of acid orange II (AO7) onto the composites at pH 5.2 also showed that the presence of CuFe 2 O 4 did not affect the adsorption capacity of the activated carbon. The thermal decomposition of AO7 adsorbed on the activated carbon and the composite was investigated by in situ FTIR, respectively. The results suggest that the composite has much higher catalytic activity than that of activated carbon, attributed to the presence of CuFe 2 O 4 . The variation of the adsorption capacity of the composites after several adsorption-regeneration cycles has also been studied.

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Section: Ftir Spectra For Ao7 On the Composite And Its Catalytic Degrmentioning

confidence: 99%

CuFe2O4/activated carbon composite: A novel magnetic adsorbent for the removal of acid orange II and catalytic regeneration

et al. 2007

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“…3n, o). This result could be explained that DOM acted as both a photo-sensitizer of TiO 2 at low concentration (Stylidi et al, 2004) and a scavenger of OH• at high concentration. This suggests that DOM can suppress the removal of DPAA by TiO 2 by prohibiting the adsorption of DPAA on TiO 2 particles and the generation of OH• by TiO 2 .…”

Section: Effect Of Soil Properties On Generation Of Oh• By Tio 2 -Esrmentioning

confidence: 96%

Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

Wang

Teng

et al. 2016

Science of The Total Environment

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Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO 2 ) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L 9 (3) 4 , only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO 2 dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg −1 were found to be a 1:10 soil: water ratio, 40 mW cm −2 light intensity, 5% TiO 2 in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5 h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil Contents lists available at ScienceDirectScience of the Total Environment j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / s c i t o t e n v electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO 2 in soil slurry. This study suggests that TiO 2 photocatalytic oxidation is a promising treatment for removing DPAA from soil.

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“…4(c)), about 95% of AO7 solution was discolored after only 30 min, with the solution displaying no spectral features. The absorption spectrum features of AO7 at 485, 310 and 228 nm correlate with the structural features of azo linkage, naphthalene and benzene rings of AO7, respectively [15]. The relevant first-order kinetics of the transformation of AO7 at three spectral wavelengths are listed in Table 1.…”

Section: Comparison Of Mwl and Telmentioning

confidence: 99%

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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Visible light-induced photocatalytic degradation of Acid Orange 7 in aqueous TiO2 suspensions

Cited by 618 publications

References 38 publications

CuFe2O4/activated carbon composite: A novel magnetic adsorbent for the removal of acid orange II and catalytic regeneration

CuFe2O4/activated carbon composite: A novel magnetic adsorbent for the removal of acid orange II and catalytic regeneration

Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

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

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