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Öğe Catalytic wet air oxidation of oxalic acid at atmospheric pressure(Berkeley Electronic Press, 2007) Gunduz, Gonul; Dukkanci, MeralCatalytic wet air oxidation of oxalic acid in aqueous solution was investigated in a stirred reactor over a Pt (0.7% in wt)/Al2O3 catalyst at atmospheric pressure, in a concentration range of oxalic acid of 500-3000 ppm, and at a temperature range of 313-353 K. The conversions obtained after 5 h were 28.96 %, 45.98 % and 30.74 % for initial concentrations of 500, 1500, 3000 ppm, respectively. A rate equation of oxalic acid oxidation, in mol.h-1.g-1Pt was determined from measurements of initial rates, at different initial concentrations of oxalic acid, temperatures and catalyst mass loads. The activation energy for oxalic acid conversion was found to be 24.6 kJ mol-1.The heterogeneous catalyzed free-radical oxidation of oxalic acid was discussed.Öğe Degradation of a textile dye, Rhodamine 6G (Rh6G), by heterogeneous sonophotoFenton process in the presence of Fe-containing TiO2 catalysts(Springer Heidelberg, 2015) Demir, Nazli; Gunduz, Gonul; Dukkanci, MeralIn this study, degradation of Rhodamine 6G (Rh6G) was investigated with ultrasound-assisted heterogeneous photoFenton process by iron-containing TiO2 catalysts. The catalysts were prepared by incipient wetness impregnation method and characterized by XRD, SEM, FT-IR, nitrogen adsorption, and ICP-AES measurements. Almost complete color removal (99.9 %) was achieved after a reaction time of 90 min while chemical oxygen demand (COD) could be removed by 24 % only with the 1 wt% iron-containing TiO2 catalyst. Initial color removal after 15 min of reaction and total COD abatement after 90 min of reaction decreased with increasing calcination temperature of the catalyst from 573 to 973 K. This indicated that the catalytic activity of the catalyst depend on the percentage of anatase phase in the TiO2, which was decreased with increasing calcination temperature.Öğe Degradation of a textile dye, Rhodamine 6G (Rh6G), by heterogeneous sonophotoFenton process in the presence of Fe-containing TiO2 catalysts(Springer Heidelberg, 2015) Demir, Nazli; Gunduz, Gonul; Dukkanci, MeralIn this study, degradation of Rhodamine 6G (Rh6G) was investigated with ultrasound-assisted heterogeneous photoFenton process by iron-containing TiO2 catalysts. The catalysts were prepared by incipient wetness impregnation method and characterized by XRD, SEM, FT-IR, nitrogen adsorption, and ICP-AES measurements. Almost complete color removal (99.9 %) was achieved after a reaction time of 90 min while chemical oxygen demand (COD) could be removed by 24 % only with the 1 wt% iron-containing TiO2 catalyst. Initial color removal after 15 min of reaction and total COD abatement after 90 min of reaction decreased with increasing calcination temperature of the catalyst from 573 to 973 K. This indicated that the catalytic activity of the catalyst depend on the percentage of anatase phase in the TiO2, which was decreased with increasing calcination temperature.Öğe Degradation of a textile dye, Rhodamine 6G (Rh6G), by heterogeneous sonophotoFenton process in the presence of Fe-containing TiO2 catalysts(Springer Heidelberg, 2015) Demir, Nazli; Gunduz, Gonul; Dukkanci, MeralIn this study, degradation of Rhodamine 6G (Rh6G) was investigated with ultrasound-assisted heterogeneous photoFenton process by iron-containing TiO2 catalysts. The catalysts were prepared by incipient wetness impregnation method and characterized by XRD, SEM, FT-IR, nitrogen adsorption, and ICP-AES measurements. Almost complete color removal (99.9 %) was achieved after a reaction time of 90 min while chemical oxygen demand (COD) could be removed by 24 % only with the 1 wt% iron-containing TiO2 catalyst. Initial color removal after 15 min of reaction and total COD abatement after 90 min of reaction decreased with increasing calcination temperature of the catalyst from 573 to 973 K. This indicated that the catalytic activity of the catalyst depend on the percentage of anatase phase in the TiO2, which was decreased with increasing calcination temperature.Öğe Degradation of acetic acid by heterogeneous Fenton-like oxidation over iron-containing ZSM-5 zeolites(Elsevier Science Bv, 2015) Cihanoglu, Aydin; Gunduz, Gonul; Dukkanci, MeralIn this study, the degradation of acetic acid was investigated by heterogeneous Fenton-like oxidation in the presence of iron-containing ZSM-5 zeolites. Iron content and Bronsted acidity of the catalyst affected positively and significantly the activity of catalyst in acetic acid (AA) degradation. The catalysts were prepared by ion-exchange method by using ZSM-5 type zeolites with different Si/AI ratio and characterized by XRD, SEM, FT-IR, ICP-AES and nitrogen adsorption measurements. The catalyst (IE-FeZSM-5 (90)) with Si/AI ratio of 42 and iron content of 8.5% (in wt) was found to be the most active catalyst in AA degradation. The influence of temperature, initial concentration of acid, amounts of H2O2 and catalyst and solution pH was investigated on degradation of AA by heterogeneous Fenton-like oxidation over this catalyst. Degradation of AA was accelerated at pH around 4 and temperature, H2O2 amount, catalyst loading and initial concentration of AA affected significantly the destruction of acid. The optimum conditions were obtained to be 0.2 g of catalyst, 333 K of temperature, solution pH of 4 and H2O2 amount of 8.35 mmol for an AA concentration of 0.1 g/dm(3) with a COD removal of 50.5%. Degradation of AA obeyed first order kinetics with a rate expression of -r(AA) = 2.56 x 10(7)e(-61.5/RT) C-AA where -r(AA) in mol/dm(3) min, R in kJ/mol.K, T in K and C-AA in mol/dm(3). Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.Öğe Degradation of acetic acid by heterogeneous Fenton-like oxidation over iron-containing ZSM-5 zeolites(Elsevier Science Bv, 2015) Cihanoglu, Aydin; Gunduz, Gonul; Dukkanci, MeralIn this study, the degradation of acetic acid was investigated by heterogeneous Fenton-like oxidation in the presence of iron-containing ZSM-5 zeolites. Iron content and Bronsted acidity of the catalyst affected positively and significantly the activity of catalyst in acetic acid (AA) degradation. The catalysts were prepared by ion-exchange method by using ZSM-5 type zeolites with different Si/AI ratio and characterized by XRD, SEM, FT-IR, ICP-AES and nitrogen adsorption measurements. The catalyst (IE-FeZSM-5 (90)) with Si/AI ratio of 42 and iron content of 8.5% (in wt) was found to be the most active catalyst in AA degradation. The influence of temperature, initial concentration of acid, amounts of H2O2 and catalyst and solution pH was investigated on degradation of AA by heterogeneous Fenton-like oxidation over this catalyst. Degradation of AA was accelerated at pH around 4 and temperature, H2O2 amount, catalyst loading and initial concentration of AA affected significantly the destruction of acid. The optimum conditions were obtained to be 0.2 g of catalyst, 333 K of temperature, solution pH of 4 and H2O2 amount of 8.35 mmol for an AA concentration of 0.1 g/dm(3) with a COD removal of 50.5%. Degradation of AA obeyed first order kinetics with a rate expression of -r(AA) = 2.56 x 10(7)e(-61.5/RT) C-AA where -r(AA) in mol/dm(3) min, R in kJ/mol.K, T in K and C-AA in mol/dm(3). Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.Öğe Degradation of acetic acid by heterogeneous Fenton-like oxidation over iron-containing ZSM-5 zeolites(Elsevier Science Bv, 2015) Cihanoglu, Aydin; Gunduz, Gonul; Dukkanci, MeralIn this study, the degradation of acetic acid was investigated by heterogeneous Fenton-like oxidation in the presence of iron-containing ZSM-5 zeolites. Iron content and Bronsted acidity of the catalyst affected positively and significantly the activity of catalyst in acetic acid (AA) degradation. The catalysts were prepared by ion-exchange method by using ZSM-5 type zeolites with different Si/AI ratio and characterized by XRD, SEM, FT-IR, ICP-AES and nitrogen adsorption measurements. The catalyst (IE-FeZSM-5 (90)) with Si/AI ratio of 42 and iron content of 8.5% (in wt) was found to be the most active catalyst in AA degradation. The influence of temperature, initial concentration of acid, amounts of H2O2 and catalyst and solution pH was investigated on degradation of AA by heterogeneous Fenton-like oxidation over this catalyst. Degradation of AA was accelerated at pH around 4 and temperature, H2O2 amount, catalyst loading and initial concentration of AA affected significantly the destruction of acid. The optimum conditions were obtained to be 0.2 g of catalyst, 333 K of temperature, solution pH of 4 and H2O2 amount of 8.35 mmol for an AA concentration of 0.1 g/dm(3) with a COD removal of 50.5%. Degradation of AA obeyed first order kinetics with a rate expression of -r(AA) = 2.56 x 10(7)e(-61.5/RT) C-AA where -r(AA) in mol/dm(3) min, R in kJ/mol.K, T in K and C-AA in mol/dm(3). Crown Copyright (C) 2014 Published by Elsevier B.V. All rights reserved.Öğe Degradation of bisphenol-a using a sonophoto Fenton-like hybrid process over a LaFeO3 perovskite catalyst and a comparison of its activity with that of a TiO2 photocatalyst(Scientific Technical Research Council Turkey-Tubitak, 2016) Dukkanci, MeralOxidation of bisphenol-A (BPA) was investigated using a sonophoto Fenton-like hybrid process under visible light irradiation in the presence of iron-containing perovskite LaFeO3 catalysts. For this purpose, firstly the perovskite catalyst (LaFeO3) was prepared by the sol-gel method and calcined at different temperatures (500, 700, and 800 degrees C). The prepared catalysts were characterized using XRD, SEM, FTIR, nitrogen adsorption, UV-vis DRS, and ICP/OES measurements. Among the prepared catalysts the catalyst that was calcined at 500 degrees C showed better catalytic activity with respect to degradation and chemical oxygen demand (COD) reduction (of 21.8% and 11.2%, respectively, after 3 h of reaction duration) than the other catalysts calcined at 700 degrees C and 800 degrees C. The catalytic activity of the LaFeO3 perovskite catalyst calcined at 500 degrees C was compared with that of a TiO2 photocatalyst containing Fe and prepared by the sol-gel method. Better photocatalytic activity in terms of degradation of BPA, total organic carbon (TOC), and COD reductions was observed with the LaFeO3 perovskite catalyst under visible light. The degradation, COD, and TOC reductions after 6 h of oxidation were 34.8%, 26.9%, and 8.8% for the LaFeO3 perovskite catalyst, and 33.1%, 19.7%, and 4.9% for the Fe/TiO2 catalyst, respectively.Öğe Degradation of CI Reactive Red 141 by heterogeneous Fenton-like process over iron-containing ZSM-5 zeolites(Wiley-Blackwell, 2013) Yaman, Yadigar C.; Gunduz, Gonul; Dukkanci, MeralThe Fenton-like oxidation of CI Reactive Red 141 was investigated over iron-containing ZSM-5 zeolites. Iron was loaded by ion exchange or through hydrothermal synthesis. The oxidation process was carried out in an aqueous solution using hydrogen peroxide as the oxidant. The catalyst prepared by ion exchange with a silicon/aluminium ratio of 42 zeolite showed the highest activity (97% decolorisation and 52% chemical oxygen demand reduction at an initial pH of 3.5) after an oxidation duration of 2 h. The chemical oxygen demand reduction increased with the increasing amount of iron loaded to the zeolite. The FeZSM-5 catalyst, prepared by hydrothermal synthesis in the presence of oxalic acid, showed very good activity in terms of mineralisation (99% of chemical oxygen demand reduction). The iron leaching was noticeably low (below the European Union directives of 2 mg dm(-3)) for the above-mentioned catalysts.Öğe Degradation of CI Reactive Red 141 by heterogeneous Fenton-like process over iron-containing ZSM-5 zeolites(Wiley-Blackwell, 2013) Yaman, Yadigar C.; Gunduz, Gonul; Dukkanci, MeralThe Fenton-like oxidation of CI Reactive Red 141 was investigated over iron-containing ZSM-5 zeolites. Iron was loaded by ion exchange or through hydrothermal synthesis. The oxidation process was carried out in an aqueous solution using hydrogen peroxide as the oxidant. The catalyst prepared by ion exchange with a silicon/aluminium ratio of 42 zeolite showed the highest activity (97% decolorisation and 52% chemical oxygen demand reduction at an initial pH of 3.5) after an oxidation duration of 2 h. The chemical oxygen demand reduction increased with the increasing amount of iron loaded to the zeolite. The FeZSM-5 catalyst, prepared by hydrothermal synthesis in the presence of oxalic acid, showed very good activity in terms of mineralisation (99% of chemical oxygen demand reduction). The iron leaching was noticeably low (below the European Union directives of 2 mg dm(-3)) for the above-mentioned catalysts.Öğe Effects of catalyst preparation method and reaction parameters on the ultrasound assisted Photocatalytic oxidation of reactive yellow 84 dye(Bmc, 2020) Donmez, Ozge; Dukkanci, Meral; Gunduz, GonulIn this study, the Heterogeneous Sono-photocatalytic Process was used to degrade Reactive Yellow 84 (RY 84) dye dissolved in water over iron containing TiO(2)and TiO2-Ce catalysts. the catalysts were prepared by sol-gel and incipient wetness impregnation methods and characterized using XRD, SEM, Nitrogen adsorption, UV-Vis DRS and ICP-AES measurements. the TiO(2)catalyst containing 1% (in weight) iron, prepared by incipient wetness impregnation technique and calcined at 300 degrees C (1%Fe/TiO2-300 degrees C (IW)) was found to be the most effective catalyst. Parametric study was carried out over this catalyst and COD removal of 55% and TOC removal of 38% were achieved while the decolorization efficiency reached 100% after 45 min of reaction at the optimum conditions of, (25 mg/L of RY 84 solution, 0.5 g/L of catalyst, 5 mM of H2O2, a temperature of 25 degrees C, pH = 6 and US at a power of 40 W). Decolorization of RY 84 obeyed the first order kinetics with an activation energy of 20.7 kJ/mol. Sonication increased the decolorization efficiency of the heterogeneous Fenton process (UV + Catalyst+H2O2) from 92.7% to 97.5% after 30 min of reaction, with the COD and TOC reductions increasing from 87% to 90% and 48% to 57% after 120 min of reaction, respectively. US also decreased the toxicity of the RY 84 dye. the results obtained from this study show that, iron containing TiO(2)and TiO2-Ce catalysts could be efficiently used in the hybrid process of ultrasound assisted heterogeneous photocatalytic oxidation in a wide range of experimental conditions.Öğe Fabrication of magnetically separable plasmonic composite photocatalyst of Ag/AgBr/ZnFe2O4 for visible light photocatalytic oxidation of carbamazepine(Elsevier, 2020) Yentur, Gizem; Dukkanci, MeralMagnetically separable visible-light response Ag/AgBr/ZnFe2O4 plasmonic composite photocatalyst was synthesized and characterized by XRD, XPS, SEM, EDS, N-2 Adsorption-Desorption (BET), VSM and, UV-Vis Diffuse Reflectance Spectra (DRS). Inductively Coupled Plasma (ICP) analysis was performed for measurement of leaching amount of Ag from catalyst to solution. the visible-light photocatalytic activity of the as-prepared Ag/AgBr/ZnFe2O4 was evaluated by the degradation of pharmaceutical drug, Carbamazepine (CBZ), and the Zscheme mechanism of Ag/AgBr/ZnFe2O4 heterostructure photocatalyst was explained by the conduction and valance bands levels of semiconductors. the photocatalytic activity was also performed with the addition of oxidants of H2O2 and persulfate (PS). Addition of PS increased the photocatalytic activity of catalyst, however, H2O2 addition caused a decrease in photocatalytic activity. According to results of radical scavengers runs, the O-2(center dot-) and SO4 center dot- were confirmed to be the main active species in photocatalytic process both in the absence and in the presence of oxidants. Besides, Ag/AgBr/ZnFe2O4 is superparamagnetic and can be recycled by external magnet after photocatalytic reaction. Toxicity tests were also performed and the results showed that the intermediates formed in the photocatalytic oxidation of CBZ were less toxic compared to the parent CBZ molecule under the experimental conditions used.Öğe Fe Containing ZSM-5 Zeolite as Catalyst for Wet Peroxide Oxidation of Orange II(Walter De Gruyter & Co, 2011) Bolova, Emre; Gunduz, Gonul; Dukkanci, Meral; Yilmaz, Selahattin; Yaman, Yadigar CeydaThis study presents the catalytic performances of iron containing ZSM-5 zeolites, prepared by ion exchange or hydrothermal synthesis, in catalytic Fenton-like oxidation of Orange II in aqueous solution. The catalyst, ZSM-5 zeolite with Si/Al ratio of 42 loaded with iron by ion exchange, showed the highest activity. The decolorization of 99.7 percent, degradation of 87.0 percent and COD removal of 81.2 percent were achieved over this catalyst at an initial pH of 3.5. Incorporation of iron into ZSM-5 structure increased its catalytic activity. The hydrothermally prepared FeZSM-5 catalyst was more stable against leaching at low pH value due to the iron being in the framework.Öğe g-C3N4 supported Ag/AgCl@MIL-88A MOF based triple composites for highly efficient diuron photodegradation under visible LED light irradiation(Elsevier, 2023) Akgun, Didem; Dukkanci, MeralIn this work, a series of g-C3N4 supported Ag/AgCl doped MIL-88A composites were synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectroscopy (UV-vis DRS), and photoluminescence spectroscopy (PL). The photocatalytic performances of as-prepared composites were examined by the photodegradation of diuron (DRN), which is used as an herbicide in agriculture. The composites exhibit exceptional visible-light photocatalytic activities for photodegradation of DRN with complete degradation within 60 min in the absence of oxidants. However, in the presence of H2O2 or persulfate, complete degradation of DRN was achieved in 15 min and 30 min, respectively. The photocatalyst also gave very high conversions in water containing dissolved inorganic salts and natural organic matter (NOM). The Ag/AgCl@MIL-88A/g-C3N4 composite retained excellent photocatalytic properties after repeated use. Radical trapping experiments revealed that the most important reactive species in the photodegradation were O-2(-center dot) and h(+). Role of active radicals were discussed via proposed degradation mechanism for the degradation of DRN in the presence of MIL-88A/g-C3N4 and Ag/AgCl@MIL-88A/g-C3N4.Öğe Heterogeneous Fenton-like Degradation of Orange II in Water Using FeZSM-5 Zeolite Catalyst(Walter De Gruyter Gmbh, 2012) Bolova, Emre; Gunduz, Gonul; Dukkanci, MeralIn this study, Fenton-like degradation of Orange II in water was investigated over an FeZSM-5 zeolite catalyst prepared by ion exchange. A color removal of 99.99% and a COD elimination of 55.0% were achieved after a reaction time of 2h at 266.7 mM H2O2 at 323 K for 0.05 g/dm3 of Orange II solution at a pH around 7. Initial decolorization rate was described by an equation of -rAo = 6.4x103 e-30.7/RT COII, o CH2O2,o0.3 where R is in kJ/mol. No significant decay in decolorization efficiency of the used catalyst was observed.Öğe Heterogeneous Fenton-like oxidation of crystal violet using an iron loaded ZSM-5 zeolite(Desalination Publ, 2016) Unnu, Burcu Akin; Gunduz, Gonul; Dukkanci, MeralThe heterogeneous Fenton-like oxidation of a cationic triphenylmethane dye, crystal violet (CV), dissolved in water was investigated using an iron-loaded ZSM-5 zeolite catalyst. The catalyst was characterized by powder X-ray diffraction patterns, Fourier Transform infrared spectroscopy (FTIR), scanning electron microscope, analysis, and nitrogen adsorption-Brunauer-Emmet-Teller (N-2-BET) studies. The effects of temperature, solution pH, H2O2 amount, catalyst amount, and initial dye concentration were investigated using the heterogeneous Fenton-like oxidation of an aqueous CV. The increase in the concentration of H2O2 from 3 to 7.5mM enhanced the decolorization. Whereas increasing the H2O2 amount from 7.5 to 10mM led to a decrease in the color removal from 94.1 to 85.5%. An acidic pH of 3.5 was favorable for the decolorization of the dye. The decolorization of the dye decreased with the increase in the initial concentration of CV. Doubling the amount of the catalyst enhanced the decolorization from 94.1 to 99.6% while the chemical oxygen demand (COD) removal changed from 50 to 58.8%. The increase in temperature positively affected the decolorization and the COD reduction of the dye. The stability of the catalyst was maintained even after using the catalyst for three cycles, and a small iron leaching was also proof of the stability of the catalyst. The initial color removal rate of the CV was described as -r(CV),(o)=7.3e(-14.7/RT)C(CV,o)(0.7) where R=8.314J/mol K and C-CV,C-o and were in mol/dm(3).Öğe Heterogeneous sonocatalytic degradation of Bisphenol-A and the influence of the reaction parameters and ultrasonic frequency(Iwa Publishing, 2019) Dukkanci, MeralIn the present study, the sonocatalytic oxidation of Bisphenol-A (BPA) was investigated in the presence of a LaFeO3 perovskite catalyst. The effects of the reaction temperature, initial pH, catalyst loading, presence of inorganic anions and sonication source (power and frequency) on the removal of BPA using heterogeneous sonocatalytic process were investigated. Under the studied temperature range of 288-318 K, 308 K was selected as the optimum temperature and the highest BPA removal and total oxygen demand (TOC) reduction of, 95.8% and 30.4% were achieved at that temperature. The thermodynamic parameters were calculated in the studied temperature range of 288-308 K. It was seen that an acidic pH of 3.0 was favorable for the BPA oxidation with the highest BPA removal and TOC reduction of 95.4% and 31.5%, respectively. Doubling the catalyst amount from 0.25 g/L to 0.5 g/L increased the BPA removal degree from 81.6% to 90.8%. However, further increase in catalyst amount has no remarkable positive effect on the removal of BPA. The removal of BPA was described by the first order kinetics with an activation energy of 14.9 kJ/mol. The results obtained from this study showed that the LaFeO3 perovskite catalyst was a good sonocatalyst giving high oxidation rates of BPA.Öğe Influence of ultrasound on the heterogeneous Fenton-like oxidation of acetic acid(Iwa Publishing, 2017) Cihanoglu, Aydin; Gunduz, Gonul; Dukkanci, MeralThe main objective of this study is to investigate the effect of ultrasound on the heterogeneous Fenton-like oxidation of acetic acid, which is one of the most resistant carboxylic acids to oxidation. For this purpose, firstly, the degradation of acetic acid was examined by using ultrasound alone and the effects of different parameters such as: type of sonication system, ultrasonic power, and addition of H2O2 were investigated on the degradation of acetic acid. There was no chemical oxygen demand (COD) reduction in the presence of sonication alone. In the presence of the heterogeneous Fentonlike oxidation process alone, at 303 K, COD reduction reached only 7.1% after 2 h of reaction. However, the combination of the heterogeneous Fenton-like oxidation process with ultrasound increased the COD reduction from 7.1% to 25.5% after 2 h of reaction in an ultrasonic bath operated at 40 kHz, while the COD reduction only increased from 7.1% to 8.9% in the ultrasonic reactor operated at 850 kHz. This result indicates that the hybrid process of ultrasound and heterogeneous Fenton-like oxidation is a promising process to degrade acetic acid.Öğe A Parametric Study on the Heterogeneous Photo-Fenton-Like Oxidation of Bisphenol-A over an Fe/TiO2 Catalyst under Visible Light(Gazi Univ, 2017) Dukkanci, MeralIn this study the oxidation of Bisphenol-A (BPA) was investigated using heterogeneous photo-Fenton-like oxidation under visible light irradiation over iron containing TiO2 catalysts. The catalysts were prepared by the incipient wetness impregnation method with different iron contents (1 and 5 wt%) and characterized by XRD, SEM, FT-IR, nitrogen adsorption, UV-Vis DRS, and ICP-AES measurements. Among the prepared catalysts the 1 wt% iron containing the TiO2 catalyst showed better catalytic activity (with a chemical oxygen demand (COD) reduction of 65.4% at the end of 6h of oxidation) than the other catalysts. The effects of the parameters such as the initial BPA concentration, H2O2 amount, catalyst amount, the pH of the initial BPA solution, and reaction temperature were studied with that catalyst on the heterogeneous photo-Fenton-like oxidation of an aqueous BPA solution. The small amount of iron that leached to the solution and the reusability of the catalyst illustrates that the process is mainly the heterogeneous photo-Fenton-like process, instead of the homogeneous photo-Fenton-like process. The degradation of BPA was described by the first order kinetics with an activation energy of 22.5 kJ/Mol.Öğe Preparation and characterisation of silver- or copper-doped TiO2 catalysts and their catalytic activity in dye degradation(Wiley, 2015) Lozovskyi, Oleksandr; Gunduz, Gonul; Dukkanci, Meral; Prihod'ko, RomanIn this study, silver- or copper-doped TiO2-Ce-, TiO2-La-, and commercial TiO2 (P25)-supported catalysts were prepared. The catalysts and supports were characterised by powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and nitrogen adsorption studies. UV-light-assisted heterogeneous Fenton-like oxidation of two different-structure dyes (anionic azo dye Orange II, CI Acid Orange 7 and cationic triphenylmethane dye Crystal Violet, CI Basic Violet 3) was investigated over the catalysts. Higher catalytic activity was observed in the oxidation of Orange II than in the oxidation of Crystal Violet. For both dyes, the TiO2-Ce and TiO2-La-supported catalysts, which were in the form of anatase only, gave higher photocatalytic activity than the P25-supported catalysts, which were in the form of anatase and rutile. Complete colour removal was observed during oxidation of Orange II over Cu/TiO2-Ce and Cu/TiO2-La catalysts, whereas the highest degree of decolorisation, 89.3%, was achieved by oxidation of Crystal Violet over Ag/TiO2-Ce. The pH of the solution affected the surface state of the TiO2, thus affecting the photocatalytic degradation of the dyes. The surface area of the catalysts is also a key parameter that influences their photocatalytic activity. It was observed that catalysts having higher surface areas brought about greater dye degradation.