N. Birben, C. S. Uyguner-Demirel, S. Sen-Kavurmaci, Y. Y. Gürkan, Nazlı Türkten, M. Kılıç, Zekiye Çınar, M. Bekbolet
Abstract TiO2 photocatalysis has gained a great interest as an innovative and effective treatment process for the removal of complex organic matter present in water and wastewater. Employment of TiO2 as a photocatalyst has its limitations due to its wide band gap that causes utilization of very small fraction of solar light. In that respect, structural modifications of TiO2, such as metal and non-metal doping have been revealed in detail to benefit from solar radiation for photocatalytic applications. In this study, photocatalytic performances of C-doped, N-doped, S-doped and S-N co-doped TiO2 photocatalysts were investigated for the degradation of a high molecular size fraction of humic acid as a representative of complex organic matrix. For this purpose, 100 kDa molecular size fraction of humic acid solution was subjected to both solar (Solar/PC) and UV (UV/PC) photocatalytic oxidation processes. Degradation kinetics and removal percentages were comparatively evaluated in terms of humic UV-vis parameters (Color436 and UV254) and dissolved organic carbon contents. Moreover, advanced fluorescence techniques in the form of an excitation-emission matrix (EEM) of fluorescence intensity as a function of excitation and emission wavelengths were also applied. Comparison of the photocatalytic removal efficiencies of different anion doped TiO2 specimens revealed higher performance of solar photocatalytic oxidation process in terms of the selected humic parameters. EEM fluorescence features displayed the removal of humic-like fluorophores and emergence of fulvic-like fluorophores in accordance with removal extent of dissolved organic carbon contents which could be attributed to the performances of anion doped TiO2 specimens as S-N co-doped>N-doped>C-doped>S-doped>bare for UV/PC process.
{"title":"Photocatalytic Performance of Anion Doped TiO2 on the Degradation of Complex Organic Matrix","authors":"N. Birben, C. S. Uyguner-Demirel, S. Sen-Kavurmaci, Y. Y. Gürkan, Nazlı Türkten, M. Kılıç, Zekiye Çınar, M. Bekbolet","doi":"10.1515/jaots-2016-0203","DOIUrl":"https://doi.org/10.1515/jaots-2016-0203","url":null,"abstract":"Abstract TiO2 photocatalysis has gained a great interest as an innovative and effective treatment process for the removal of complex organic matter present in water and wastewater. Employment of TiO2 as a photocatalyst has its limitations due to its wide band gap that causes utilization of very small fraction of solar light. In that respect, structural modifications of TiO2, such as metal and non-metal doping have been revealed in detail to benefit from solar radiation for photocatalytic applications. In this study, photocatalytic performances of C-doped, N-doped, S-doped and S-N co-doped TiO2 photocatalysts were investigated for the degradation of a high molecular size fraction of humic acid as a representative of complex organic matrix. For this purpose, 100 kDa molecular size fraction of humic acid solution was subjected to both solar (Solar/PC) and UV (UV/PC) photocatalytic oxidation processes. Degradation kinetics and removal percentages were comparatively evaluated in terms of humic UV-vis parameters (Color436 and UV254) and dissolved organic carbon contents. Moreover, advanced fluorescence techniques in the form of an excitation-emission matrix (EEM) of fluorescence intensity as a function of excitation and emission wavelengths were also applied. Comparison of the photocatalytic removal efficiencies of different anion doped TiO2 specimens revealed higher performance of solar photocatalytic oxidation process in terms of the selected humic parameters. EEM fluorescence features displayed the removal of humic-like fluorophores and emergence of fulvic-like fluorophores in accordance with removal extent of dissolved organic carbon contents which could be attributed to the performances of anion doped TiO2 specimens as S-N co-doped>N-doped>C-doped>S-doped>bare for UV/PC process.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"180 1","pages":"199 - 207"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80156841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Sulfate modified SiO2-TiO2 photocatalysts with different SO42− loadings were prepared by incipient-wetness impregnation method using H2SO4 solution with various concentrations. The as-prepared SO42−/SiO2-TiO2 samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer- Emmett-Teller (BET) method, Uv-vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and terephthalic acid photoluminescence probing technique (TA-PL), respectively. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of rhodamine B under ultraviolet light irradiation. The effects of H2SO4 solution concentration on the structure, morphology, surface properties and photocatalytic activity of SO42−/SiO2-TiO2 samples were investigated. The results indicated that the catalyst prepared with 4 mol/L H2SO4 solution, it showed the highest photocatalytic activity. The higher photocatalytic activity could be attributed to the improved surface properties and the enhanced separation rate of photoinduced electron-hole pairs.
{"title":"Photocatalytic Degradation of Rhodamine B over Sulfated SiO2-TiO2 Composite by Sulphuric Acid Impregnation Method","authors":"Xuemin Yan, P. Mei, Lin Gao","doi":"10.1515/jaots-2016-0106","DOIUrl":"https://doi.org/10.1515/jaots-2016-0106","url":null,"abstract":"Abstract Sulfate modified SiO2-TiO2 photocatalysts with different SO42− loadings were prepared by incipient-wetness impregnation method using H2SO4 solution with various concentrations. The as-prepared SO42−/SiO2-TiO2 samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer- Emmett-Teller (BET) method, Uv-vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and terephthalic acid photoluminescence probing technique (TA-PL), respectively. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of rhodamine B under ultraviolet light irradiation. The effects of H2SO4 solution concentration on the structure, morphology, surface properties and photocatalytic activity of SO42−/SiO2-TiO2 samples were investigated. The results indicated that the catalyst prepared with 4 mol/L H2SO4 solution, it showed the highest photocatalytic activity. The higher photocatalytic activity could be attributed to the improved surface properties and the enhanced separation rate of photoinduced electron-hole pairs.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"21 1","pages":"52 - 58"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76505398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract 2-methylisoborneol (2-MIB) is a common odor-causing compound in drinking water with a low odor threshold (10 ng/L). Since conventional treatment processes cannot effectively remove it, this study investigated an advanced oxidation technology: UV/H2O2 decomposing the compound in laboratory and pilot trials. The results show that, in the laboratory trials, the removal efficiency of 2-MIB increased with the concentration of H2O2 increasing; 764 ng/L of 2-MIB was reduced to 2 ng/L after 8 min reaction with 3.92 mg/L of H2O2; 702 ng/L of 2-MIB was reduced to 42 ng/L after 8 min reaction with 1.93 mg/L of H2O2; the degradation of 2-MIB conformed to first-order kinetics. The data obtained from the pilot trials was analyzed with software Design- Expert, determining the optimal operation conditions (the H2O2 dosage of 6 mg/L, the UV dose of 350 mJ/cm2, and the 2-MIB dose of 275 ng/L) with the highest 2-MIB removal percentage of 96.58%. The reaction rate between UV/H2O2 and 2-MIB was accessed through this software by fitting experimental data.
{"title":"Optimization of Removal of 2-methylisoborneol from Drinking Water using UV/H2O2","authors":"F. Tan, Haihan Chen, Daoji Wu, N. Lu, Zhimin Gao","doi":"10.1515/jaots-2016-0113","DOIUrl":"https://doi.org/10.1515/jaots-2016-0113","url":null,"abstract":"Abstract 2-methylisoborneol (2-MIB) is a common odor-causing compound in drinking water with a low odor threshold (10 ng/L). Since conventional treatment processes cannot effectively remove it, this study investigated an advanced oxidation technology: UV/H2O2 decomposing the compound in laboratory and pilot trials. The results show that, in the laboratory trials, the removal efficiency of 2-MIB increased with the concentration of H2O2 increasing; 764 ng/L of 2-MIB was reduced to 2 ng/L after 8 min reaction with 3.92 mg/L of H2O2; 702 ng/L of 2-MIB was reduced to 42 ng/L after 8 min reaction with 1.93 mg/L of H2O2; the degradation of 2-MIB conformed to first-order kinetics. The data obtained from the pilot trials was analyzed with software Design- Expert, determining the optimal operation conditions (the H2O2 dosage of 6 mg/L, the UV dose of 350 mJ/cm2, and the 2-MIB dose of 275 ng/L) with the highest 2-MIB removal percentage of 96.58%. The reaction rate between UV/H2O2 and 2-MIB was accessed through this software by fitting experimental data.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"170 1","pages":"104 - 98"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87599871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Wastewaters polluted with non-biodegradable volatile organic compounds (VOCs), such as aromatic substances, present a growing problem meeting no adequately affordable technological response. Low-temperature plasma generated in the gas-phase pulsed corona discharge (PCD) presents competitive advanced oxidation technology in abatement of various classes of pollutants, although the process parameters, the pulse repetition frequency and the liquid spray rate, require optimization. The experimental research into aqueous benzene oxidation with PCD was undertaken to establish the impact of the parameters to the energy efficiency. The oxidation reaction was found under the experimental conditions to mostly proceed in the gas phase showing little influence of the pulse repetition frequency and the gas-liquid contact surface. Oxidation of benzene and, presumably, other volatile pollutants in the volume of PCD reactor compartment presents an effective strategy of aqueous VOCs abatement.
{"title":"Aqueous Benzene Oxidation in Low-Temperature Plasma of Pulsed Corona Discharge","authors":"I. Kornev, S. Preis","doi":"10.1515/jaots-2016-0212","DOIUrl":"https://doi.org/10.1515/jaots-2016-0212","url":null,"abstract":"Abstract Wastewaters polluted with non-biodegradable volatile organic compounds (VOCs), such as aromatic substances, present a growing problem meeting no adequately affordable technological response. Low-temperature plasma generated in the gas-phase pulsed corona discharge (PCD) presents competitive advanced oxidation technology in abatement of various classes of pollutants, although the process parameters, the pulse repetition frequency and the liquid spray rate, require optimization. The experimental research into aqueous benzene oxidation with PCD was undertaken to establish the impact of the parameters to the energy efficiency. The oxidation reaction was found under the experimental conditions to mostly proceed in the gas phase showing little influence of the pulse repetition frequency and the gas-liquid contact surface. Oxidation of benzene and, presumably, other volatile pollutants in the volume of PCD reactor compartment presents an effective strategy of aqueous VOCs abatement.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"83 1","pages":"284 - 289"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79343083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract FeCrBAlMo coating was deposited on an AISI 20 steel substrate by high velocity arc spraying (HVAS). Compared with FeCrBSiMo coating and pristine AISI 20 steel, the microstructure and high temperature oxidation behavior of FeCrBAlMo coating were investigated by optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Meanwhile, the bonding strength of the coatings was also measured. The results indicated that both coatings were composed of α(Fe,Cr) and Fe2O3 phases. FeCrBAlMo coating had a denser structure and a higher bonding strength than FeCrBSiMo coating. The mass gain of FeCrBAlMo coating after oxidization at high temperatures was distinctly lower than that of FeCrBSiMo coating and AISI 20 steel substrate. In place of silicon, addition of aluminum increased the high temperature oxidation resistance and improved the quality of the coating.
{"title":"High Temperature Oxidation Behavior of Arc-sprayed FeCrBAlMo Coating","authors":"Xin Zhang, Zehua Wang, Jinran Lin","doi":"10.1515/jaots-2016-0114","DOIUrl":"https://doi.org/10.1515/jaots-2016-0114","url":null,"abstract":"Abstract FeCrBAlMo coating was deposited on an AISI 20 steel substrate by high velocity arc spraying (HVAS). Compared with FeCrBSiMo coating and pristine AISI 20 steel, the microstructure and high temperature oxidation behavior of FeCrBAlMo coating were investigated by optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction. Meanwhile, the bonding strength of the coatings was also measured. The results indicated that both coatings were composed of α(Fe,Cr) and Fe2O3 phases. FeCrBAlMo coating had a denser structure and a higher bonding strength than FeCrBSiMo coating. The mass gain of FeCrBAlMo coating after oxidization at high temperatures was distinctly lower than that of FeCrBSiMo coating and AISI 20 steel substrate. In place of silicon, addition of aluminum increased the high temperature oxidation resistance and improved the quality of the coating.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"33 1","pages":"105 - 112"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76352608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Benzothiazoles are emerging chemical pollutants mainly coming from leather, paper and rubber industries; due to their use as: herbicides, corrosion inhibitors, anti-freezers, and vulcanisation accelerators. This article presents experimental data on ozone treatment of benzothiazole contaminated waters. The effect of the initial concentration of benzothiazole, ozone dosage, temperature (10-30 °C), and pH (2-9), on ozonation removal rate were assessed at bench scale. Experimental results show that reaction between ozone and benzothiazole could be approximated to a second-order kinetic law. Kinetic parameters for direct and indirect ozone reactions are estimated and temperature dependence of rate parameters is evaluated. Moreover, an initial degradation pathway of benzothiazole ozonation is proposed.
{"title":"Removal of Benzothiazole from Contaminated Waters by Ozonation: The Role of Direct and Indirect Ozone Reactions","authors":"H. Valdés, C. Zaror, M. Jekel","doi":"10.1515/jaots-2016-0218","DOIUrl":"https://doi.org/10.1515/jaots-2016-0218","url":null,"abstract":"Abstract Benzothiazoles are emerging chemical pollutants mainly coming from leather, paper and rubber industries; due to their use as: herbicides, corrosion inhibitors, anti-freezers, and vulcanisation accelerators. This article presents experimental data on ozone treatment of benzothiazole contaminated waters. The effect of the initial concentration of benzothiazole, ozone dosage, temperature (10-30 °C), and pH (2-9), on ozonation removal rate were assessed at bench scale. Experimental results show that reaction between ozone and benzothiazole could be approximated to a second-order kinetic law. Kinetic parameters for direct and indirect ozone reactions are estimated and temperature dependence of rate parameters is evaluated. Moreover, an initial degradation pathway of benzothiazole ozonation is proposed.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"138 1","pages":"338 - 346"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89027839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tianxin Li, Xin Zhang, Shili Wu, Linglong Meng, H. O. Ikhumhen
Abstract In this study, the clinoptilolite is taken as the matrix, manganese nitrate as a modifier; through a medium temperature calcination pore making technique. Mostly, the micro pores in the matrix have been enlarged through the means of dipping and high temperature calcination modification. A small amount of active catalytic components are exchanged stably between the pores and surface. The mechanism of manufacturing new catalyst is analyzed using test methods of TEM, SEM, EDS, XRD and BET. These test methods testify the existence of active catalytic components of manganese in the Mn-Zeolite, while researching a new type of Mn-zeolite catalyst heterogeneous catalytic mechanism of Fenton and ozone oxidation process. The results show that added Mn-zeolite could improve the oxidation rate from 51% to 100%. Addition of free radical inhibitor, t-butanol, significantly inhibited the catalytic reaction of Fenton and ozone oxidation. This indicated that the mechanism of the reaction of Fenton and ozonation followed the hydroxyl radical.
{"title":"Purification Mechanism Analysis and performance Characterization of Mn-zeolite Catalyst","authors":"Tianxin Li, Xin Zhang, Shili Wu, Linglong Meng, H. O. Ikhumhen","doi":"10.1515/jaots-2016-0122","DOIUrl":"https://doi.org/10.1515/jaots-2016-0122","url":null,"abstract":"Abstract In this study, the clinoptilolite is taken as the matrix, manganese nitrate as a modifier; through a medium temperature calcination pore making technique. Mostly, the micro pores in the matrix have been enlarged through the means of dipping and high temperature calcination modification. A small amount of active catalytic components are exchanged stably between the pores and surface. The mechanism of manufacturing new catalyst is analyzed using test methods of TEM, SEM, EDS, XRD and BET. These test methods testify the existence of active catalytic components of manganese in the Mn-Zeolite, while researching a new type of Mn-zeolite catalyst heterogeneous catalytic mechanism of Fenton and ozone oxidation process. The results show that added Mn-zeolite could improve the oxidation rate from 51% to 100%. Addition of free radical inhibitor, t-butanol, significantly inhibited the catalytic reaction of Fenton and ozone oxidation. This indicated that the mechanism of the reaction of Fenton and ozonation followed the hydroxyl radical.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"44 1","pages":"171 - 181"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90660510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Electrocatalytic synthesis of oxalic acid from acetylene has been achieved at Pt electrode. The electrocatalytically synthesized oxalic acid has been characterized by FTIR (Fourier transform infrared spectroscopy) and UV-Vis (UV-Vis spectrophotometry). Influence of electrode material, Na2SO4 concentration, acetone volume fraction, temperature and scan rate have been investigated by CV (cyclic voltammetry). The analysis results show that oxalic acid has been successfully electrocatalytically synthesized from acetylene at the very stable Pt electrode under ambient temperature and pressure, the supporting electrolyte is Na2SO4 (0.5 M) with acetone (2% by volume), the reaction time is 8 h and the conversion efficiency is larger than 20%. The Ea (apparent activation energy) of electrocatalytic oxidation reaction of acetylene at the Pt electrode is 14.42 kJ·mol-1, the electrocatalytic oxidation process of acetylene is irreversible and under adsorption control. In addition, the reaction mechanism of the electrocatalytic oxidation process of acetylene to oxalic acid has been envisaged successfully based on the principle of adsorption and desorption at Pt electrode surface. It exhibits the excellent electrocatalytic performance of Pt in the electrocatalytic oxidation process of acetylene and heralds more broad potential application prospect of acetylene in chemical industry field.
{"title":"Electrochemical Behavior of Electrocatalytic Synthesis of Oxalic Acid from Acetylene at Pt Electrode","authors":"Xiuli Song, Wenyan Dong, Zhenhai Liang","doi":"10.1515/jaots-2016-0108","DOIUrl":"https://doi.org/10.1515/jaots-2016-0108","url":null,"abstract":"Abstract Electrocatalytic synthesis of oxalic acid from acetylene has been achieved at Pt electrode. The electrocatalytically synthesized oxalic acid has been characterized by FTIR (Fourier transform infrared spectroscopy) and UV-Vis (UV-Vis spectrophotometry). Influence of electrode material, Na2SO4 concentration, acetone volume fraction, temperature and scan rate have been investigated by CV (cyclic voltammetry). The analysis results show that oxalic acid has been successfully electrocatalytically synthesized from acetylene at the very stable Pt electrode under ambient temperature and pressure, the supporting electrolyte is Na2SO4 (0.5 M) with acetone (2% by volume), the reaction time is 8 h and the conversion efficiency is larger than 20%. The Ea (apparent activation energy) of electrocatalytic oxidation reaction of acetylene at the Pt electrode is 14.42 kJ·mol-1, the electrocatalytic oxidation process of acetylene is irreversible and under adsorption control. In addition, the reaction mechanism of the electrocatalytic oxidation process of acetylene to oxalic acid has been envisaged successfully based on the principle of adsorption and desorption at Pt electrode surface. It exhibits the excellent electrocatalytic performance of Pt in the electrocatalytic oxidation process of acetylene and heralds more broad potential application prospect of acetylene in chemical industry field.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"95 1","pages":"66 - 72"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80441009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chang‐Mao Hung, Chiu-wen Chen, Yu-Zhe Jhuang, C. Dong
Abstract In this study, the oxidation of methylene blue (MB) over iron oxide magnetic nanoparticles (Fe3O4), which effectively activates persulfate anions (S2O82−) to form sulfate free radicals (SO4−•), was explored. In addition, the effect of the initial pH, sodium persulfate (Na2S2O8, PS) concentration, and Fe3O4 content on the decolorization of MB was investigated. The results revealed that the decolorization rate increased when the persulfate concentration increased from 0.03 to 0.12 g/L and the Fe3O4 content from 0.1 to 0.8 g/L. Therefore, the Fe3O4 nanoparticles enhanced the decolorization of MB. The catalyst was analyzed using cyclic voltammetry (CV), three-dimensional excitation-emission fluorescence matrix (EEFM) spectroscopy, and zeta potential measurements. The CV spectra indicated that a reversible redox reaction may explain the high catalytic activity of the catalyst. EEFM was used to evaluate the yield of a fresh Fe3O4 catalyst, and two peaks were observed at EX/EM wavelengths of 230/300 nm and 270/300 nm. Furthermore, the structure and surface morphology of the catalyst were characterized using X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM)-energy dispersive spectroscopy (EDS), respectively. The XRD result confirmed the existence of Fe3O4 in the catalyst. ESEM was used to determine the Fe3O4 particle size, indicating a high degree of nanoparticle dispersion.
{"title":"Fe3O4 Magnetic Nanoparticles: Characterization and Performance Exemplified by the Degradation of Methylene Blue in the Presence of Persulfate","authors":"Chang‐Mao Hung, Chiu-wen Chen, Yu-Zhe Jhuang, C. Dong","doi":"10.1515/jaots-2016-0105","DOIUrl":"https://doi.org/10.1515/jaots-2016-0105","url":null,"abstract":"Abstract In this study, the oxidation of methylene blue (MB) over iron oxide magnetic nanoparticles (Fe3O4), which effectively activates persulfate anions (S2O82−) to form sulfate free radicals (SO4−•), was explored. In addition, the effect of the initial pH, sodium persulfate (Na2S2O8, PS) concentration, and Fe3O4 content on the decolorization of MB was investigated. The results revealed that the decolorization rate increased when the persulfate concentration increased from 0.03 to 0.12 g/L and the Fe3O4 content from 0.1 to 0.8 g/L. Therefore, the Fe3O4 nanoparticles enhanced the decolorization of MB. The catalyst was analyzed using cyclic voltammetry (CV), three-dimensional excitation-emission fluorescence matrix (EEFM) spectroscopy, and zeta potential measurements. The CV spectra indicated that a reversible redox reaction may explain the high catalytic activity of the catalyst. EEFM was used to evaluate the yield of a fresh Fe3O4 catalyst, and two peaks were observed at EX/EM wavelengths of 230/300 nm and 270/300 nm. Furthermore, the structure and surface morphology of the catalyst were characterized using X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM)-energy dispersive spectroscopy (EDS), respectively. The XRD result confirmed the existence of Fe3O4 in the catalyst. ESEM was used to determine the Fe3O4 particle size, indicating a high degree of nanoparticle dispersion.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"92 1","pages":"43 - 51"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83560267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li Li, Zheng Ma, Feifei Bi, Hong Li, Wenjie Zhang, Hongbo He
Abstract Composite Bi4Ti3O12/SiO2 photocatalysts were prepared through sol-gel synthesizing of Bi4Ti3O12 on quartz spheres. The Bi4Ti3O12 supported on the micrometer-sized quartz spheres is in a perovskite structure with shrinking crystallite size. SEM and EDX images demonstrate the well dispersion of Bi4Ti3O12 on the quartz spheres. Both Bi4Ti3O12 and χBi4Ti3O12/SiO2 have small surface area due to the very limited porous structure. Chemical environments of Bi4Ti3O12 do not noticeably change after loading on SiO2. Photocatalytic activities of most supported χBi4Ti3O12/SiO2 are improved with the maximum activity on 50%Bi4Ti3O12/SiO2. Total decoloration of Reactive Brilliant Red-X3B is achieved on 50%Bi4Ti3O12/SiO2 after 90 min under UV light irradiation.
{"title":"Sol-gel Preparation and Properties of Bi4Ti3O12 Photocatalyst Supported on Micrometer-sized Quartz Spheres","authors":"Li Li, Zheng Ma, Feifei Bi, Hong Li, Wenjie Zhang, Hongbo He","doi":"10.1515/jaots-2016-0215","DOIUrl":"https://doi.org/10.1515/jaots-2016-0215","url":null,"abstract":"Abstract Composite Bi4Ti3O12/SiO2 photocatalysts were prepared through sol-gel synthesizing of Bi4Ti3O12 on quartz spheres. The Bi4Ti3O12 supported on the micrometer-sized quartz spheres is in a perovskite structure with shrinking crystallite size. SEM and EDX images demonstrate the well dispersion of Bi4Ti3O12 on the quartz spheres. Both Bi4Ti3O12 and χBi4Ti3O12/SiO2 have small surface area due to the very limited porous structure. Chemical environments of Bi4Ti3O12 do not noticeably change after loading on SiO2. Photocatalytic activities of most supported χBi4Ti3O12/SiO2 are improved with the maximum activity on 50%Bi4Ti3O12/SiO2. Total decoloration of Reactive Brilliant Red-X3B is achieved on 50%Bi4Ti3O12/SiO2 after 90 min under UV light irradiation.","PeriodicalId":14870,"journal":{"name":"Journal of Advanced Oxidation Technologies","volume":"38 1","pages":"310 - 316"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86037169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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