The photocatalytic degradation of Rhodamine B (RhB) was carried out using TiO2 supported on activated carbon (TiO2-AC) under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X...The photocatalytic degradation of Rhodamine B (RhB) was carried out using TiO2 supported on activated carbon (TiO2-AC) under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). In the process of microwave-enhanced photocatalysis (MPC), RhB (30 mg/L) was almost completely decoloured in 10 min, and the mineralization efficiency was 96.0% in 20 min. The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 4.16 times of that using Degussa P25. Additionally, according to gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates (N,N-diethyl-N'-ethyl-rhodamine (DER)), oxalic acid, malonic acid, snccinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on. The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide.展开更多
BiOClxBr1-x catalysts were synthesized through an alcoholysis method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM)...BiOClxBr1-x catalysts were synthesized through an alcoholysis method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and diffuse reflectance spectroscopy (DRS). The as-prepared photocatalysts were found to be tetragonal crystal structure and lamellar plate morphology. Their band gaps were between 3.44 and 2.83 eV. The effect of light response on the photocatalytic activity of BiOClxBrl-x was investigated by degradation of Rhodamine B (RhB). Complete removal of RhB from water was realized under simulated sunlight irradiation for 50 min with BiOC10.5Br0.5. Mechanism studies showed that photo- generated holes and superoxide anion radicals played important roles in RhB photodegradation. The results of chemical oxygen demand (COD) confirmed RhB mineralization. The effect of light response on the activity of BiOClxBr1-x was further investigated under monochromatic light irradiation, and BiOCl0.5Br0.5 catalyst exhibited the highest activity. Furthermore, BiOC10.5Br0.5 exhibited high stability, suggesting its practical application for the removal of RhB pollutant from water.展开更多
Achieving efficient degradation of organic pollutants via activation of sulfite is meaningful but challenging.Herein,we have constructed a heterogeneous catalyst system involving Co_(3)O_(4) and TiO_(2) nanoparticles ...Achieving efficient degradation of organic pollutants via activation of sulfite is meaningful but challenging.Herein,we have constructed a heterogeneous catalyst system involving Co_(3)O_(4) and TiO_(2) nanoparticles to form the p-n heterojunction(Co_(3)O_(4)/TiO_(2)) to degrade acetaminophen(ACE) through photocatalytic activation of sulfite.Specifically,X-ray photoelectron spectroscopy analysis and theoretical calculations provide compelling evidence of electron transfer from Co_(3)O_(4) to TiO_(2) at the heterointerface.The interfacial electron redistribution of Co_(3)O_(4)/TiO_(2) tunes the adsorption energy of HSO_(3)^(-)/SO_(3)^(2-) in sulfite activation process for enhanced the catalytic activity.Owing to its unique heterointerface,the degradation efficiency of ACE reached 96.78%within 10 min.The predominant active radicals were identified as ·OH,h^(+),and SO_(x)^(·-) through radical quenching experiments and electron spin resonance capture.Besides,the possible degradation pathway was deduced by monitoring the generated intermediate products.Thereafter,the enhanced roles of well-engineered compositing interface in photocatalytic activation of sulfite for complete degradation of ACE were unveiled that it can improve light absorption ability,facilitate the generation of active species,and optimize reactive pathways.Considering that sulfite is a waste from flue gas desulfurization process,the photocatalytic activation of sulfite system will open up new avenues of beneficial use of air pollutants for the removal of pharmaceutical wastewater.展开更多
The rapid degradation of organic pollutants,process monitoring and online controlling to obtain advanced products and decreased by-products are great and challenging tasks in environmental treatments.Herein,an acceler...The rapid degradation of organic pollutants,process monitoring and online controlling to obtain advanced products and decreased by-products are great and challenging tasks in environmental treatments.Herein,an accelerated plasma degradation in milliseconds was achieved by combining electrospray-based acceleration and plasma-based degradation.Taking the degradation of chloroaniline as an example,97%of the degradation can be achieved in milliseconds.The velocity distribution of droplets was determined to be 40-50 m/s after being degraded for 0.30 ms,which exhibited different degradation behaviors in different milliseconds.Simultaneously,by virtue of the real-time and on-line detection ability of ambient mass spectrometry,intermediates,by-products and advanced products were monitored.Therefore,degradation mechanisms for different degradation times were proposed,which would provide theoretical guidance on obtaining efficient and green degradation.The fabrication,examining and understanding of accelerated plasma degradation not only enlarged application of accelerated reactions,but also promoted green and efficient degradation for environmental treatments.展开更多
基金supported by the National Natural Science Foundation of China (No. 20707009)the Jiangsu Province Social Development Foundation (No.BS2007051)+1 种基金the Opening Foundation (WTWER0713) of Engineering Research Center for Water Treatment and Water Remediation of the Ministry of Education of Chinathe State Key Laboratory of Pollution Control and Resource Reuse Opening Foundation (No. PCRRCF07003).
文摘The photocatalytic degradation of Rhodamine B (RhB) was carried out using TiO2 supported on activated carbon (TiO2-AC) under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). In the process of microwave-enhanced photocatalysis (MPC), RhB (30 mg/L) was almost completely decoloured in 10 min, and the mineralization efficiency was 96.0% in 20 min. The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 4.16 times of that using Degussa P25. Additionally, according to gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS) identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates (N,N-diethyl-N'-ethyl-rhodamine (DER)), oxalic acid, malonic acid, snccinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on. The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide.
基金the National Natural Science Foundation of China(No.21176168)the International Science and Technology Cooperation Program of Shanxi Province,China(No.2012081017)the Science and Technology Project of Taiyuan(No.20120164016)
文摘BiOClxBr1-x catalysts were synthesized through an alcoholysis method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and diffuse reflectance spectroscopy (DRS). The as-prepared photocatalysts were found to be tetragonal crystal structure and lamellar plate morphology. Their band gaps were between 3.44 and 2.83 eV. The effect of light response on the photocatalytic activity of BiOClxBrl-x was investigated by degradation of Rhodamine B (RhB). Complete removal of RhB from water was realized under simulated sunlight irradiation for 50 min with BiOC10.5Br0.5. Mechanism studies showed that photo- generated holes and superoxide anion radicals played important roles in RhB photodegradation. The results of chemical oxygen demand (COD) confirmed RhB mineralization. The effect of light response on the activity of BiOClxBr1-x was further investigated under monochromatic light irradiation, and BiOCl0.5Br0.5 catalyst exhibited the highest activity. Furthermore, BiOC10.5Br0.5 exhibited high stability, suggesting its practical application for the removal of RhB pollutant from water.
基金financially supported by the National Natural Science Foundation of China(No.51878273)the Natural Science Foundation of Hebei Province(No.E2019502199)。
文摘Achieving efficient degradation of organic pollutants via activation of sulfite is meaningful but challenging.Herein,we have constructed a heterogeneous catalyst system involving Co_(3)O_(4) and TiO_(2) nanoparticles to form the p-n heterojunction(Co_(3)O_(4)/TiO_(2)) to degrade acetaminophen(ACE) through photocatalytic activation of sulfite.Specifically,X-ray photoelectron spectroscopy analysis and theoretical calculations provide compelling evidence of electron transfer from Co_(3)O_(4) to TiO_(2) at the heterointerface.The interfacial electron redistribution of Co_(3)O_(4)/TiO_(2) tunes the adsorption energy of HSO_(3)^(-)/SO_(3)^(2-) in sulfite activation process for enhanced the catalytic activity.Owing to its unique heterointerface,the degradation efficiency of ACE reached 96.78%within 10 min.The predominant active radicals were identified as ·OH,h^(+),and SO_(x)^(·-) through radical quenching experiments and electron spin resonance capture.Besides,the possible degradation pathway was deduced by monitoring the generated intermediate products.Thereafter,the enhanced roles of well-engineered compositing interface in photocatalytic activation of sulfite for complete degradation of ACE were unveiled that it can improve light absorption ability,facilitate the generation of active species,and optimize reactive pathways.Considering that sulfite is a waste from flue gas desulfurization process,the photocatalytic activation of sulfite system will open up new avenues of beneficial use of air pollutants for the removal of pharmaceutical wastewater.
基金the financial support provided by the National Key Research and Development Program of China(No.2019YFC1805600)the National Natural Science Foundation of China(Nos.21874012,21974010).
文摘The rapid degradation of organic pollutants,process monitoring and online controlling to obtain advanced products and decreased by-products are great and challenging tasks in environmental treatments.Herein,an accelerated plasma degradation in milliseconds was achieved by combining electrospray-based acceleration and plasma-based degradation.Taking the degradation of chloroaniline as an example,97%of the degradation can be achieved in milliseconds.The velocity distribution of droplets was determined to be 40-50 m/s after being degraded for 0.30 ms,which exhibited different degradation behaviors in different milliseconds.Simultaneously,by virtue of the real-time and on-line detection ability of ambient mass spectrometry,intermediates,by-products and advanced products were monitored.Therefore,degradation mechanisms for different degradation times were proposed,which would provide theoretical guidance on obtaining efficient and green degradation.The fabrication,examining and understanding of accelerated plasma degradation not only enlarged application of accelerated reactions,but also promoted green and efficient degradation for environmental treatments.