Efficiently and thoroughly degrading organic dyes in wastewater is of great importance and challenge.Herein,vertically oriented mesoporous a-Fe_(2)O_(3)nanorods array(a-Fe_(2)O_(3)-NA)is directly grown on fluorine-dop...Efficiently and thoroughly degrading organic dyes in wastewater is of great importance and challenge.Herein,vertically oriented mesoporous a-Fe_(2)O_(3)nanorods array(a-Fe_(2)O_(3)-NA)is directly grown on fluorine-doped tin oxide(FTO)glass and employed as the photoanode for photoelectrocatalytic degradation of methylene blue simulated dye wastewater.The Ovsites on the a-Fe_(2)O_(3)-NA surface are the active sites for methylene blue(MB)adsorption.Electrons transfer from the adsorbed MB to Fe-O is detected.Compared with electrocatalytic and photocatalytic degradation processes,the photoelectrocatalytic(PEC)process exhibited the best degrading performance and the largest kinetic constant.Hydroxyl,superoxide free radicals,and photo-generated holes play a jointly leading role in the PEC degradation.A possible degrading pathway is suggested by liquid chromatography-mass spectroscopy analysis.This work demonstrates that photoelectrocatalysis by a-Fe_(2)O_(3)-NA has a remarkable superiority over photocatalysis and electrocatalysis in MB degradation.The in-depth investigation of photoelectrocatalytic degradation mechanism in this study is meaningful for organic wastewater treatment.展开更多
Given the difficulties of degrading benzotriazole(BTA),this study used a one-pot hydrothermal method to prepareα-Fe_(2)O_(3)/Cu_(2)O(FC)composites for photoelectrocatalytic(PEC)degradation of BTA.The characterization...Given the difficulties of degrading benzotriazole(BTA),this study used a one-pot hydrothermal method to prepareα-Fe_(2)O_(3)/Cu_(2)O(FC)composites for photoelectrocatalytic(PEC)degradation of BTA.The characterization of FC structure showed that Cu_(2)O in cubic crystals was loaded with circular sheets of Fe_(2)O_(3).Owing to this structure,FC showed efficient PEC degradation of BTA when exposed to ultraviolet light.The experimental results demonstrated that FC efficiently degraded BTA.When the PEC degradation continued for 60 min,100%degradation of BTA was achieved because FC enhanced the photoelectron-hole separation and the separation and transfer of articulated carriers.High per-formance liquid chromatography-mass spectrometry showed that intermediates formed during the PEC degradation of BTA.Finally,various pathways for degradation of BTA were postulated.This FC-based PEC system provides a harmless and effective method for degradation of BTA.展开更多
A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natur...A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.展开更多
An innovative photoelectrode, B 2O 3·TiO 2/Ti electrode, was prepared by galvanostaticanodisation. The morphology and crystalline texture of the B 2O 3·TiO 2 film on electrode were examined by atomic force m...An innovative photoelectrode, B 2O 3·TiO 2/Ti electrode, was prepared by galvanostaticanodisation. The morphology and crystalline texture of the B 2O 3·TiO 2 film on electrode were examined by atomic force microscopy(AFM) and X-ray diffraction respectively. The examination results indicated that the anatase was the dominant component. The kinetics of photoelectrocatalytic(PEC) degradation of humic acid(HA) was investigated; the results demonstrated that effects from strongness to weakness on the photoelectrocatalytic degraded rate of humic acid: power of UV-lamp, area of TiO 2 film, bias, original concentration of humic acid solution. The optimum conditions were power of UV-lamp 125 W, area of TiO 2 film 42.0 cm 2, bias 1.4 V, original concentration of humic acid solution 5 mg/L in this PEC reaction system.展开更多
An innovative photoelectrode, TiO 2/Ti mesh electrode, was prepared by galvanostaticanodisation. The morphology and the crystalline texture of the TiO 2 film on mesh electrode were examined by scanning electronic micr...An innovative photoelectrode, TiO 2/Ti mesh electrode, was prepared by galvanostaticanodisation. The morphology and the crystalline texture of the TiO 2 film on mesh electrode were examined by scanning electronic microscopy and Raman spectroscopy respectively. The examination results indicated that the structure and properties of the film depended on anodisation rate, and the anatase was the dominant component under the controlled experimental conditions. Degradation of Rose Bengal(RB) in photocatalytic(PC) and photoelectrocatalytic(PEC) reaction was investigated, the results demonstrated that electric biasing could improve the efficiency of photocatalytic reaction. The measurement results of TOC in photoelectrocatalytic degradation showed that the mineralisation of RB was complete relatively. The comparison between the degradation efficiency of RB in PEC process and that in aqueous TiO 2 dispersion was conducted. The results showed that the apparent first order rate constant of RB degradation in PEC process was larger than that in aqueous dispersion with 0 1%—0 3% TiO 2 powder, but was smaller than that in aqueous dispersion with 1 0% TiO展开更多
In this study,sulfur-doped TiO2 /Ti photoelectrodes were prepared by anodization. The morphology, crystalline structure,composition of sulfur-doped TiO2 /Ti film and light absorption property were examined by SEM,XRD,...In this study,sulfur-doped TiO2 /Ti photoelectrodes were prepared by anodization. The morphology, crystalline structure,composition of sulfur-doped TiO2 /Ti film and light absorption property were examined by SEM,XRD,XRF,XPS and UV/VIS respectively. Dimethyl phthalate( DMP) ,one kind of environmental disrupting chemicals( EDCs) ,was degraded by the optimized photoelectrodes. Power of xenon light,initial concentration of DMP,photoelectrocatalytic( PEC) area of photoelectrode and bias were investigated in the study on kinetics of PEC degradation of DMP. Hence,this study concluded that the optimum conditions were power of xenon light 150 W,initial concentration of DMP 1 mg/L,PEC area of sulfur-doped TiO2 /Ti photoelectrode 10 cm2,bias 1. 3 V in the PEC reaction system.展开更多
The method of Ti/TiO2-NiO photoelectrode prepared by using sol-gel method continued by calcination process was introduced. The prepared TiO2-NiO film was observed with XRD and TEM. The anatase-rutile TiO2 was mainly o...The method of Ti/TiO2-NiO photoelectrode prepared by using sol-gel method continued by calcination process was introduced. The prepared TiO2-NiO film was observed with XRD and TEM. The anatase-rutile TiO2 was mainly on the prepared TiO2-NiO composite surface electrode. In addition to NiO, the composite also formed NiTiO3 that increased with increasing calcination temperature. Photoelectrocatalytic degradation of Rhodamine B (RB) using this electrode was investigated, and anodic potential and pH were optimized. RB degradation was investigated under different conditions, and it showed that photoelectrocatalytic degradation could achieve efficient and complete mineralization of organic pollutant. Through comparison of the photoelectrocatalytic oxidation using the Ti/TiO2-NiO electrode operated by single photoanode with the Ti/TiO2-NiO electrode operated by several photoanode, it was found that the photoelectrocatalytic efficiency of that by series photoanodes was higher. Additionally, photoelectrocatalytic system was performed at the several different photoelectrodes, which verified the higher photocatalytic activity compared with the single photoelectrode.展开更多
Developing a high-quality photoelectrode for photoelectrochemical applications is still an ongoing challenge. In this study, we prepared the g-C_(3)N_(4) film on the indium tin oxide(ITO) glass through conventional co...Developing a high-quality photoelectrode for photoelectrochemical applications is still an ongoing challenge. In this study, we prepared the g-C_(3)N_(4) film on the indium tin oxide(ITO) glass through conventional coating, liquid-based growth, in-situ calcination, and vapor deposition methods, respectively. These electrodes were characterized and used as photoanodes to degrade methylene blue(MB) in water. Among these methods, the in-situ calcination method was most appropriate for preparing the continuous and organized g-C_(3)N_(4) film electrodes with uniform g-C_(3)N_(4) coverage and strong adhesion to the ITO substrate.It also had the highest activity in the photocatalytic(PC), electrochemical(EC), and photoelectrocatalytic(PEC) degradation processes of MB. In the PEC reaction, at an applied potential of 1.0 V and a light intensity of 0.96 W/cm^(2), the removal rate of MB was 62.5%, which was much higher than those in the PC and EC reactions. The high degradation rate was due to the synergistic effect of PEC degradation, wherein the PC and EC reactions promote and optimize each other. In the PC reaction, MB was degraded by-CH_(3) elimination, while the EC degradation pathway mainly included the conversion of sulfhydryl into sulfoxide and the opening of the central aromatic ring. Both methyl loss and aromatic ring opening occurred in the PEC reaction. Moreover, some monocyclic compounds were formed, and MB showed more complete degradation in the PEC reaction.展开更多
SR-AOP(sulfate radical advanced oxidation process)is a novel water treatment method able to eliminate refractory organic pollutants.Hydrodynamic cavitation(HC)is a novel green technology,that can effectively produce s...SR-AOP(sulfate radical advanced oxidation process)is a novel water treatment method able to eliminate refractory organic pollutants.Hydrodynamic cavitation(HC)is a novel green technology,that can effectively produce strong oxidizing sulfate radicals.This paper presents a comprehensive review of the research advancements in these fields and a critical discussion of the principal factors influencing HC-enhanced SR-AOP and the mechanisms of synergistic degradation.Furthermore,some insights into the industrial application of HC/PS are also provided.Current research shows that this technology is feasible at the laboratory stage,but its application on larger scales requires further understanding and exploration.In this review,some attention is also paid to the design of the hydrodynamic cavitation reactor and the related operating parameters.展开更多
The degradation of Mg alloys relates to the service performance of Mg alloy biodegradable implants.In order to investigate the degradation behavior of Mg alloys as vascular stent materials in the near service environm...The degradation of Mg alloys relates to the service performance of Mg alloy biodegradable implants.In order to investigate the degradation behavior of Mg alloys as vascular stent materials in the near service environment,the hot-extruded fine-grained Mg-Zn-Y-Nd alloy microtubes,which are employed to manufacture vascular stents,were tested under radial compressive stress in the dynamic Hanks'Balanced Salt Solution(HBSS).The results revealed that the high flow rate accelerates the degradation of Mg alloy microtubes and its degradation is sensitive to radial compressive stress.These results contribute to understanding the service performance of Mg alloys as vascular stent materials.展开更多
The synergistic reaction of photocatalysis and advanced oxidation is a valid strategy for the degradation of harmful antibiotic wastewater.Herein,carbon dots(CDs)modified MIL-101(Fe)octahedrons to form CDs/MIL-101(Fe)...The synergistic reaction of photocatalysis and advanced oxidation is a valid strategy for the degradation of harmful antibiotic wastewater.Herein,carbon dots(CDs)modified MIL-101(Fe)octahedrons to form CDs/MIL-101(Fe)composite photocatalyst was synthesized for visible light-driven photocatalytic/persulfate(PS)-activated tetracycline(TC)degradation.The electron spin resonance(ESR)spectra,scavenging experiment and electrochemical analysis were carried out to reveal that the high visible light-driven photocatalytic degradation activity of TC over CDs/MIL-101(Fe)photocatalysts is not only ascribed to the production of free active radicals in the CDs/MIL-101(Fe)/PS system(·OH,·SO_(4-),^(1)O_(2),h^(+)and·O_(2)^(-))but also attributed to the consumption of electrons caused by the PS,which can suppress the recombination of photo-generated carriers as well as strong light scattering and electron trapping effects of CDs.Finally,the possible degradation pathways were proposed by analyzing intermediates via liquid chromatography-mass spectrometry technique.This research presents a rational design conception to construct a CDs/PS-based photocatalysis/advanced oxidation technology with high-efficient degradation activity for the remediation of organic antibiotic pollutant wastewater and for the improvement of carrier transport kinetics of photocatalysts.展开更多
SF_(6) has excellent insulation performance and arc extinguishing ability,and is widely used in the power industry.However,its global warming potential is about 23,500 times that of C0_(2),it can exist stably in the a...SF_(6) has excellent insulation performance and arc extinguishing ability,and is widely used in the power industry.However,its global warming potential is about 23,500 times that of C0_(2),it can exist stably in the atmosphere,it is not easily degradable and is of great potential harm to the environment.Based on pulsed dielectric barrier discharge plasma technology,the effects of H_(2)O and 0_(2) on the degradation of SF_(6) were studied.Studies have shown that H_(2)O can effectively promote the decomposition of SF_(6) and improve its degradation rate and energy efficiency of degradation.Under the action of a pulse input voltage and input frequency of 15 kV and 15 kHz,respectively,when H_(2)O is added alone the effect of 1% H_(2)O is the best,and the rate and energy efficiency of degradation of SF_(6) reach their maximum values,which are 91.9% and 8.25 g kWh^(-1),respectively.The synergistic effect of H_(2)O and O_(2) on the degradation of SF_(6) was similar to that of H_(2)O.When the concentration of H_(2)O and O_(2) was 1%,the system obtained the best rate and energy efficiency of degradation,namely 89.7% and 8.05 g kWh~(-1),respectively.At the same time,different external gases exhibit different capabilities to regulate decomposition products.The addition of H_(2)O can effectively improve the selectivity of S0_(2).Under the synergistic effect of H_(2)O and O_(2),with increase in O_(2) concentration the degradation products gradually transformed into SO_(2)F_(2).From the perspective of harmless treatment of the degradation products of SF_(6),the addition of O_(2) during the SF_(6) degradation process should be avoided.展开更多
Deep Convolutional Neural Networks(CNNs)have achieved high accuracy in image classification tasks,however,most existing models are trained on high-quality images that are not subject to image degradation.In practice,i...Deep Convolutional Neural Networks(CNNs)have achieved high accuracy in image classification tasks,however,most existing models are trained on high-quality images that are not subject to image degradation.In practice,images are often affected by various types of degradation which can significantly impact the performance of CNNs.In this work,we investigate the influence of image degradation on three typical image classification CNNs and propose a Degradation Type Adaptive Image Classification Model(DTA-ICM)to improve the existing CNNs’classification accuracy on degraded images.The proposed DTA-ICM comprises two key components:a Degradation Type Predictor(DTP)and a Degradation Type Specified Image Classifier(DTS-IC)set,which is trained on existing CNNs for specified types of degradation.The DTP predicts the degradation type of a test image,and the corresponding DTS-IC is then selected to classify the image.We evaluate the performance of both the proposed DTP and the DTA-ICMon the Caltech 101 database.The experimental results demonstrate that the proposed DTP achieves an average accuracy of 99.70%.Moreover,the proposed DTA-ICM,based on AlexNet,VGG19,and ResNet152,exhibits an average accuracy improvement of 20.63%,18.22%,and 12.9%,respectively,compared with the original CNNs in classifying degraded images.It suggests that the proposed DTA-ICM can effectively improve the classification performance of existing CNNs on degraded images,which has important practical implications.展开更多
Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage applications.Despite this,a comprehensive understanding of the mechanisms underpinning the...Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage applications.Despite this,a comprehensive understanding of the mechanisms underpinning their structural deterioration at elevated voltages remains insufficiently explored.In this study,we unveil a layer delamination phenomenon of Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2)(NNM)within the 2.0-4.3 V voltage,attributed to considerable volumetric fluctuations along the c-axis and lattice oxygen reactions induced by the simultaneous Ni^(3+)/Ni^(4+)and anion redox reactions.By introducing Mg doping to diminished Ni-O antibonding,the anion oxidation-reduction reactions are effectively mitigated,and the structural integrity of the P2 phase remains firmly intact,safeguarding active sites and precluding the formation of novel interfaces.The Na_(0.67)Mg_(0.05)Ni_(0.25)Mn_(0.7)O_(2)(NMNM-5)exhibits a specific capacity of100.7 mA h g^(-1),signifying an 83%improvement compared to the NNM material within the voltage of2.0-4.3 V.This investigation underscores the intricate interplay between high-voltage stability and structural degradation mechanisms in layered sodium-ion oxides.展开更多
In this work,monoclinic Bi_(2)O_(3) was applied for the first time,to the best of our knowledge,as a catalyst in the process of dye degradation by a non-thermal atmospheric-pressure positive pulsating corona discharge...In this work,monoclinic Bi_(2)O_(3) was applied for the first time,to the best of our knowledge,as a catalyst in the process of dye degradation by a non-thermal atmospheric-pressure positive pulsating corona discharge.The research focused on the interaction of the plasma-generated species and the catalyst,as well as the role of the catalyst in the degradation process.Plasma decomposition of the anthraquinone reactive dye Reactive Blue 19(RB 19) was performed in a selfmade reactor system.Bi_(2)O_(3) was prepared by electrodeposition followed by thermal treatment,and characterized by x-ray diffraction,scanning electron microscopy and energy-dispersive xray techniques.It was observed that the catalyst promoted decomposition of plasma-generated H_(2)O_(2) into ·OH radicals,the principal dye-degrading reagent,which further attacked the dye molecules.The catalyst improved the decolorization rate by 2.5 times,the energy yield by 93.4%and total organic carbon removal by 7.1%.Excitation of the catalyst mostly occurred through strikes by plasma-generated reactive ions and radical species from the air,accelerated by the electric field,as well as by fast electrons with an energy of up to 15 eV generated by the streamers reaching the liquid surface.These strikes transferred the energy to the catalyst and created the electrons and holes,which further reacted with H_(2)O_(2) and water,producing ·OH radicals.This was indentified as the primary role of the catalyst in this process.Decolorization reactions followed pseudo first-order kinetics.Production of H_(2)O_(2) and the dye degradation rate increased with increase in the input voltage.The optimal catalyst dose was 500 mg·dm^(-3).The decolorization rate was a little lower in river water compared with that in deionized water due to the side reactions of ·OH radicals with organic matter and inorganic ions dissolved in the river water.展开更多
Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fen...Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.展开更多
For present solid oxide fuel cells(SOFCs),rapid performance degradation is observed in the initial aging process,and the dis-cussion of the degradation mechanism necessitates quantitative analysis.Herein,focused ion b...For present solid oxide fuel cells(SOFCs),rapid performance degradation is observed in the initial aging process,and the dis-cussion of the degradation mechanism necessitates quantitative analysis.Herein,focused ion beam-scanning electron microscopy was em-ployed to characterize and reconstruct the ceramic microstructures of SOFC anodes.The lattice Boltzmann method(LBM)simulation of multiphysical and electrochemical processes in the reconstructed models was performed.Two samples collected from industrial-size cells were characterized,including a reduced reference cell and a cell with an initial aging process.Statistical parameters of the reconstructed microstructures revealed a significant decrease in the active triple-phase boundary and Ni connectivity in the aged cell compared with the reference cell.The LBM simulation revealed that activity degradation is dominant compared with microstructural degradation during the initial aging process,and the electrochemical reactions spread to the support layer in the aged cell.The microstructural and activity de-gradations are attributed to Ni migration and coarsening.展开更多
Cascading faults have been identified as the primary cause of multiple power outages in recent years.With the emergence of integrated energy systems(IES),the conventional approach to analyzing power grid cascading fau...Cascading faults have been identified as the primary cause of multiple power outages in recent years.With the emergence of integrated energy systems(IES),the conventional approach to analyzing power grid cascading faults is no longer appropriate.A cascading fault analysis method considering multi-energy coupling characteristics is of vital importance.In this study,an innovative analysis method for cascading faults in integrated heat and electricity systems(IHES)is proposed.It considers the degradation characteristics of transmission and energy supply com-ponents in the system to address the impact of component aging on cascading faults.Firstly,degradation models for the current carrying capacity of transmission lines,the water carrying capacity and insulation performance of thermal pipelines,as well as the performance of energy supply equipment during aging,are developed.Secondly,a simulation process for cascading faults in the IHES is proposed.It utilizes an overload-dominated development model to predict the propagation path of cascading faults while also considering network islanding,electric-heating rescheduling,and load shedding.The propagation of cascading faults is reflected in the form of fault chains.Finally,the results of cascading faults under different aging levels are analyzed through numerical examples,thereby verifying the effectiveness and rationality of the proposed model and method.展开更多
Zn-doped titanium oxide (TiO2) nanotubes electrode was prepared on a titanium plate by direct anodic oxidation and immersing method in sequence. Field emission scanning electron microscopy (FESEM) showed that the Zn-d...Zn-doped titanium oxide (TiO2) nanotubes electrode was prepared on a titanium plate by direct anodic oxidation and immersing method in sequence. Field emission scanning electron microscopy (FESEM) showed that the Zn-doped TiO2 nanotubes were well aligned and organized into high density uniform arrays with diameter ranging from 50 to 90 nm. The length and the thickness were about 200 and 15 nm respectively. TiO2 anatase phase was identified by X-ray diffraction (XRD). X-ray photoelectronspec-troscopy (XPS) indicated that Zn ions were mainly located on the surface of TiO2 nanotubes in form of ZnO clusters. Compared with TiO2 nanotubes electrode,about 20 nm red shift in the spectrum of UV-vis absorption was observed. The degradation of pentachlorophenol (PCP) in aqueous solution under the same condition (initial concentration of PCP: 20 mg/L; concentration of Na2SO4: 0.01 mol/L and pH: 7.03) was carried out using Zn-doped TiO2 nanotubes electrode and TiO2 nanotubes electrode. The degradation rates of PCP using Zn-doped TiO2 nanotubes electrode were found to be twice and 5.8 times as high as that using TiO2 nanotubes electrode by UV radiation (400 μw/cm2) and visible light radiation (4500 μw/cm2),respectively. 73.5% of PCP was removed using Zn-doped TiO2 nanotubes electrode against 48.5% removed using TiO2 nanotubes electrode in 120 min under UV radiation. While under visible light radiation,the degradation efficiency of PCP was 18.4% using Zn-doped TiO2 nano-tubes electrode against 3.2% using TiO2 nanotubes electrode in 120 min. The optimum concentration of Zn doping was found to be 0.909%. The PCP degradation efficiencies of the 10 repeated experiments by Zn-doped TiO2 nanotubes electrode were rather stable with the deviation within 3.0%.展开更多
TiO_2 nanotube(Ti NT) electrodes anodized in fluorinated organic solutions were successfully prepared on Ti sheets. Field-emission scanning electron microscopy(FE-SEM) and X-ray diffraction(XRD) were performed to char...TiO_2 nanotube(Ti NT) electrodes anodized in fluorinated organic solutions were successfully prepared on Ti sheets. Field-emission scanning electron microscopy(FE-SEM) and X-ray diffraction(XRD) were performed to characterize the TiNT electrodes. The linear voltammetry results under irradiation showed that the TiNT electrode annealed at 450°C presented the highest photoelectrochemical activity. By combining photocatalytic with electrochemical process, a significantly synergetic effect on ammonia degradation was observed with Na_2SO_4 as supporting electrolyte at pH 10.7. Furthermore, the photoelectrocatalytic efficiency on the ammonia degradation was greatly enhanced in presence of chloride ions without the limitation of pH. The degradation rate was improved by 14.8 times reaching 4.98 × 10^(-2) min^(-1) at pH 10.7 and a faster degradation rate of 6.34 × 10^(-2) min^(-1)was obtained at pH 3.01. The in situ photoelectrocatalytic generated active chlorine was proposed to be responsible for the improved efficiency. On the other hand, an enhanced degradation of ammonia using TiNT electrode fabricated in fluorinated organic solution was also confirmed compared to TiNT electrode anodized in fluorinated water solution and TiO_2 film electrode fabricated by sol–gel method. Finally, the effect of chloride concentration was also discussed.展开更多
基金financially supported by the National Natural Science Foundation of China (22005097)the State Key Laboratory of Physical Chemistry of Solid Surfaces,Xiamen University,Xiamen 361005,P.R.China (201815)。
文摘Efficiently and thoroughly degrading organic dyes in wastewater is of great importance and challenge.Herein,vertically oriented mesoporous a-Fe_(2)O_(3)nanorods array(a-Fe_(2)O_(3)-NA)is directly grown on fluorine-doped tin oxide(FTO)glass and employed as the photoanode for photoelectrocatalytic degradation of methylene blue simulated dye wastewater.The Ovsites on the a-Fe_(2)O_(3)-NA surface are the active sites for methylene blue(MB)adsorption.Electrons transfer from the adsorbed MB to Fe-O is detected.Compared with electrocatalytic and photocatalytic degradation processes,the photoelectrocatalytic(PEC)process exhibited the best degrading performance and the largest kinetic constant.Hydroxyl,superoxide free radicals,and photo-generated holes play a jointly leading role in the PEC degradation.A possible degrading pathway is suggested by liquid chromatography-mass spectroscopy analysis.This work demonstrates that photoelectrocatalysis by a-Fe_(2)O_(3)-NA has a remarkable superiority over photocatalysis and electrocatalysis in MB degradation.The in-depth investigation of photoelectrocatalytic degradation mechanism in this study is meaningful for organic wastewater treatment.
基金supported by the Open Program of the Tianjin Key Laboratory of Green Chemical Engineering Process Engineering,Tiangong University,Tianjin(Grant No.GCEPE20190108)the Inner Mongolia Natural Science Foundation(Grant No.2020MS02015)the Regional Science Foundation Project of the National Natural Science Foundation of China(Grant No.42167029)
文摘Given the difficulties of degrading benzotriazole(BTA),this study used a one-pot hydrothermal method to prepareα-Fe_(2)O_(3)/Cu_(2)O(FC)composites for photoelectrocatalytic(PEC)degradation of BTA.The characterization of FC structure showed that Cu_(2)O in cubic crystals was loaded with circular sheets of Fe_(2)O_(3).Owing to this structure,FC showed efficient PEC degradation of BTA when exposed to ultraviolet light.The experimental results demonstrated that FC efficiently degraded BTA.When the PEC degradation continued for 60 min,100%degradation of BTA was achieved because FC enhanced the photoelectron-hole separation and the separation and transfer of articulated carriers.High per-formance liquid chromatography-mass spectrometry showed that intermediates formed during the PEC degradation of BTA.Finally,various pathways for degradation of BTA were postulated.This FC-based PEC system provides a harmless and effective method for degradation of BTA.
基金the National High Technology Research and Development Program of China(Grant No.2009AA063003)the National Nature Science Foundation of China(Grant No.20677039) for financial support
文摘A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.
文摘An innovative photoelectrode, B 2O 3·TiO 2/Ti electrode, was prepared by galvanostaticanodisation. The morphology and crystalline texture of the B 2O 3·TiO 2 film on electrode were examined by atomic force microscopy(AFM) and X-ray diffraction respectively. The examination results indicated that the anatase was the dominant component. The kinetics of photoelectrocatalytic(PEC) degradation of humic acid(HA) was investigated; the results demonstrated that effects from strongness to weakness on the photoelectrocatalytic degraded rate of humic acid: power of UV-lamp, area of TiO 2 film, bias, original concentration of humic acid solution. The optimum conditions were power of UV-lamp 125 W, area of TiO 2 film 42.0 cm 2, bias 1.4 V, original concentration of humic acid solution 5 mg/L in this PEC reaction system.
文摘An innovative photoelectrode, TiO 2/Ti mesh electrode, was prepared by galvanostaticanodisation. The morphology and the crystalline texture of the TiO 2 film on mesh electrode were examined by scanning electronic microscopy and Raman spectroscopy respectively. The examination results indicated that the structure and properties of the film depended on anodisation rate, and the anatase was the dominant component under the controlled experimental conditions. Degradation of Rose Bengal(RB) in photocatalytic(PC) and photoelectrocatalytic(PEC) reaction was investigated, the results demonstrated that electric biasing could improve the efficiency of photocatalytic reaction. The measurement results of TOC in photoelectrocatalytic degradation showed that the mineralisation of RB was complete relatively. The comparison between the degradation efficiency of RB in PEC process and that in aqueous TiO 2 dispersion was conducted. The results showed that the apparent first order rate constant of RB degradation in PEC process was larger than that in aqueous dispersion with 0 1%—0 3% TiO 2 powder, but was smaller than that in aqueous dispersion with 1 0% TiO
基金Sponsored by the National Natural Science Foundation of China ( Grant No 50678044)
文摘In this study,sulfur-doped TiO2 /Ti photoelectrodes were prepared by anodization. The morphology, crystalline structure,composition of sulfur-doped TiO2 /Ti film and light absorption property were examined by SEM,XRD,XRF,XPS and UV/VIS respectively. Dimethyl phthalate( DMP) ,one kind of environmental disrupting chemicals( EDCs) ,was degraded by the optimized photoelectrodes. Power of xenon light,initial concentration of DMP,photoelectrocatalytic( PEC) area of photoelectrode and bias were investigated in the study on kinetics of PEC degradation of DMP. Hence,this study concluded that the optimum conditions were power of xenon light 150 W,initial concentration of DMP 1 mg/L,PEC area of sulfur-doped TiO2 /Ti photoelectrode 10 cm2,bias 1. 3 V in the PEC reaction system.
文摘The method of Ti/TiO2-NiO photoelectrode prepared by using sol-gel method continued by calcination process was introduced. The prepared TiO2-NiO film was observed with XRD and TEM. The anatase-rutile TiO2 was mainly on the prepared TiO2-NiO composite surface electrode. In addition to NiO, the composite also formed NiTiO3 that increased with increasing calcination temperature. Photoelectrocatalytic degradation of Rhodamine B (RB) using this electrode was investigated, and anodic potential and pH were optimized. RB degradation was investigated under different conditions, and it showed that photoelectrocatalytic degradation could achieve efficient and complete mineralization of organic pollutant. Through comparison of the photoelectrocatalytic oxidation using the Ti/TiO2-NiO electrode operated by single photoanode with the Ti/TiO2-NiO electrode operated by several photoanode, it was found that the photoelectrocatalytic efficiency of that by series photoanodes was higher. Additionally, photoelectrocatalytic system was performed at the several different photoelectrodes, which verified the higher photocatalytic activity compared with the single photoelectrode.
基金financial support from the National Natural Science Foundation of China(No.51978658)。
文摘Developing a high-quality photoelectrode for photoelectrochemical applications is still an ongoing challenge. In this study, we prepared the g-C_(3)N_(4) film on the indium tin oxide(ITO) glass through conventional coating, liquid-based growth, in-situ calcination, and vapor deposition methods, respectively. These electrodes were characterized and used as photoanodes to degrade methylene blue(MB) in water. Among these methods, the in-situ calcination method was most appropriate for preparing the continuous and organized g-C_(3)N_(4) film electrodes with uniform g-C_(3)N_(4) coverage and strong adhesion to the ITO substrate.It also had the highest activity in the photocatalytic(PC), electrochemical(EC), and photoelectrocatalytic(PEC) degradation processes of MB. In the PEC reaction, at an applied potential of 1.0 V and a light intensity of 0.96 W/cm^(2), the removal rate of MB was 62.5%, which was much higher than those in the PC and EC reactions. The high degradation rate was due to the synergistic effect of PEC degradation, wherein the PC and EC reactions promote and optimize each other. In the PC reaction, MB was degraded by-CH_(3) elimination, while the EC degradation pathway mainly included the conversion of sulfhydryl into sulfoxide and the opening of the central aromatic ring. Both methyl loss and aromatic ring opening occurred in the PEC reaction. Moreover, some monocyclic compounds were formed, and MB showed more complete degradation in the PEC reaction.
文摘SR-AOP(sulfate radical advanced oxidation process)is a novel water treatment method able to eliminate refractory organic pollutants.Hydrodynamic cavitation(HC)is a novel green technology,that can effectively produce strong oxidizing sulfate radicals.This paper presents a comprehensive review of the research advancements in these fields and a critical discussion of the principal factors influencing HC-enhanced SR-AOP and the mechanisms of synergistic degradation.Furthermore,some insights into the industrial application of HC/PS are also provided.Current research shows that this technology is feasible at the laboratory stage,but its application on larger scales requires further understanding and exploration.In this review,some attention is also paid to the design of the hydrodynamic cavitation reactor and the related operating parameters.
基金the financial support of the National Key Research and Development Program of China(2018YFC1106703)the Key Projects of the Joint Fund of the National Natural Science Foundation of China(U1804251)。
文摘The degradation of Mg alloys relates to the service performance of Mg alloy biodegradable implants.In order to investigate the degradation behavior of Mg alloys as vascular stent materials in the near service environment,the hot-extruded fine-grained Mg-Zn-Y-Nd alloy microtubes,which are employed to manufacture vascular stents,were tested under radial compressive stress in the dynamic Hanks'Balanced Salt Solution(HBSS).The results revealed that the high flow rate accelerates the degradation of Mg alloy microtubes and its degradation is sensitive to radial compressive stress.These results contribute to understanding the service performance of Mg alloys as vascular stent materials.
基金the funding support from the National Natural Science Foundation of China(21906072,22006057)the Natural Science Foundation of Jiangsu Province(BK20190982)“Doctor of Mass entrepreneurship and innovation”Project in Jiangsu Province。
文摘The synergistic reaction of photocatalysis and advanced oxidation is a valid strategy for the degradation of harmful antibiotic wastewater.Herein,carbon dots(CDs)modified MIL-101(Fe)octahedrons to form CDs/MIL-101(Fe)composite photocatalyst was synthesized for visible light-driven photocatalytic/persulfate(PS)-activated tetracycline(TC)degradation.The electron spin resonance(ESR)spectra,scavenging experiment and electrochemical analysis were carried out to reveal that the high visible light-driven photocatalytic degradation activity of TC over CDs/MIL-101(Fe)photocatalysts is not only ascribed to the production of free active radicals in the CDs/MIL-101(Fe)/PS system(·OH,·SO_(4-),^(1)O_(2),h^(+)and·O_(2)^(-))but also attributed to the consumption of electrons caused by the PS,which can suppress the recombination of photo-generated carriers as well as strong light scattering and electron trapping effects of CDs.Finally,the possible degradation pathways were proposed by analyzing intermediates via liquid chromatography-mass spectrometry technique.This research presents a rational design conception to construct a CDs/PS-based photocatalysis/advanced oxidation technology with high-efficient degradation activity for the remediation of organic antibiotic pollutant wastewater and for the improvement of carrier transport kinetics of photocatalysts.
基金supported by Guizhou Province (Ceneral), grant/award number Qian Ke He Zhi Cheng [2022] General 207, National Natural Science Foundation of China (No. 52307170)Natural Science Foundation of Hubei Province, China (No. 2023AFB382)。
文摘SF_(6) has excellent insulation performance and arc extinguishing ability,and is widely used in the power industry.However,its global warming potential is about 23,500 times that of C0_(2),it can exist stably in the atmosphere,it is not easily degradable and is of great potential harm to the environment.Based on pulsed dielectric barrier discharge plasma technology,the effects of H_(2)O and 0_(2) on the degradation of SF_(6) were studied.Studies have shown that H_(2)O can effectively promote the decomposition of SF_(6) and improve its degradation rate and energy efficiency of degradation.Under the action of a pulse input voltage and input frequency of 15 kV and 15 kHz,respectively,when H_(2)O is added alone the effect of 1% H_(2)O is the best,and the rate and energy efficiency of degradation of SF_(6) reach their maximum values,which are 91.9% and 8.25 g kWh^(-1),respectively.The synergistic effect of H_(2)O and O_(2) on the degradation of SF_(6) was similar to that of H_(2)O.When the concentration of H_(2)O and O_(2) was 1%,the system obtained the best rate and energy efficiency of degradation,namely 89.7% and 8.05 g kWh~(-1),respectively.At the same time,different external gases exhibit different capabilities to regulate decomposition products.The addition of H_(2)O can effectively improve the selectivity of S0_(2).Under the synergistic effect of H_(2)O and O_(2),with increase in O_(2) concentration the degradation products gradually transformed into SO_(2)F_(2).From the perspective of harmless treatment of the degradation products of SF_(6),the addition of O_(2) during the SF_(6) degradation process should be avoided.
基金This work was supported by Special Funds for the Construction of an Innovative Province of Hunan(GrantNo.2020GK2028)lNatural Science Foundation of Hunan Province(Grant No.2022JJ30002)lScientific Research Project of Hunan Provincial EducationDepartment(GrantNo.21B0833)lScientific Research Key Project of Hunan Education Department(Grant No.21A0592)lScientific Research Project of Hunan Provincial Education Department(Grant No.22A0663).
文摘Deep Convolutional Neural Networks(CNNs)have achieved high accuracy in image classification tasks,however,most existing models are trained on high-quality images that are not subject to image degradation.In practice,images are often affected by various types of degradation which can significantly impact the performance of CNNs.In this work,we investigate the influence of image degradation on three typical image classification CNNs and propose a Degradation Type Adaptive Image Classification Model(DTA-ICM)to improve the existing CNNs’classification accuracy on degraded images.The proposed DTA-ICM comprises two key components:a Degradation Type Predictor(DTP)and a Degradation Type Specified Image Classifier(DTS-IC)set,which is trained on existing CNNs for specified types of degradation.The DTP predicts the degradation type of a test image,and the corresponding DTS-IC is then selected to classify the image.We evaluate the performance of both the proposed DTP and the DTA-ICMon the Caltech 101 database.The experimental results demonstrate that the proposed DTP achieves an average accuracy of 99.70%.Moreover,the proposed DTA-ICM,based on AlexNet,VGG19,and ResNet152,exhibits an average accuracy improvement of 20.63%,18.22%,and 12.9%,respectively,compared with the original CNNs in classifying degraded images.It suggests that the proposed DTA-ICM can effectively improve the classification performance of existing CNNs on degraded images,which has important practical implications.
基金the financial support from the National Natural Science Foundation of China(52202338)。
文摘Advancing high-voltage stability of layered sodium-ion oxides represents a pivotal avenue for their progress in energy storage applications.Despite this,a comprehensive understanding of the mechanisms underpinning their structural deterioration at elevated voltages remains insufficiently explored.In this study,we unveil a layer delamination phenomenon of Na_(0.67)Ni_(0.3)Mn_(0.7)O_(2)(NNM)within the 2.0-4.3 V voltage,attributed to considerable volumetric fluctuations along the c-axis and lattice oxygen reactions induced by the simultaneous Ni^(3+)/Ni^(4+)and anion redox reactions.By introducing Mg doping to diminished Ni-O antibonding,the anion oxidation-reduction reactions are effectively mitigated,and the structural integrity of the P2 phase remains firmly intact,safeguarding active sites and precluding the formation of novel interfaces.The Na_(0.67)Mg_(0.05)Ni_(0.25)Mn_(0.7)O_(2)(NMNM-5)exhibits a specific capacity of100.7 mA h g^(-1),signifying an 83%improvement compared to the NNM material within the voltage of2.0-4.3 V.This investigation underscores the intricate interplay between high-voltage stability and structural degradation mechanisms in layered sodium-ion oxides.
基金financial support from the Ministry of Education, Science and Technological Development of the Republic of Serbia (No.451-03-47/2023-01/200124)。
文摘In this work,monoclinic Bi_(2)O_(3) was applied for the first time,to the best of our knowledge,as a catalyst in the process of dye degradation by a non-thermal atmospheric-pressure positive pulsating corona discharge.The research focused on the interaction of the plasma-generated species and the catalyst,as well as the role of the catalyst in the degradation process.Plasma decomposition of the anthraquinone reactive dye Reactive Blue 19(RB 19) was performed in a selfmade reactor system.Bi_(2)O_(3) was prepared by electrodeposition followed by thermal treatment,and characterized by x-ray diffraction,scanning electron microscopy and energy-dispersive xray techniques.It was observed that the catalyst promoted decomposition of plasma-generated H_(2)O_(2) into ·OH radicals,the principal dye-degrading reagent,which further attacked the dye molecules.The catalyst improved the decolorization rate by 2.5 times,the energy yield by 93.4%and total organic carbon removal by 7.1%.Excitation of the catalyst mostly occurred through strikes by plasma-generated reactive ions and radical species from the air,accelerated by the electric field,as well as by fast electrons with an energy of up to 15 eV generated by the streamers reaching the liquid surface.These strikes transferred the energy to the catalyst and created the electrons and holes,which further reacted with H_(2)O_(2) and water,producing ·OH radicals.This was indentified as the primary role of the catalyst in this process.Decolorization reactions followed pseudo first-order kinetics.Production of H_(2)O_(2) and the dye degradation rate increased with increase in the input voltage.The optimal catalyst dose was 500 mg·dm^(-3).The decolorization rate was a little lower in river water compared with that in deionized water due to the side reactions of ·OH radicals with organic matter and inorganic ions dissolved in the river water.
基金supported by the Program for the National Natural Science Foundation of China(52070077,51879101,51779090)the National Program for Support of Top-Notch Young Professionals of China(2014)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University(IRT-13R17)Natural Science Foundation of Hunan Province(2022JJ20013,2021JJ40098).
文摘Carbon-doped copper ferrite(C–CuFe_(2)O_(4))was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe_(2)O_(4) in Fenton-like reaction.A removal efficiency of 94%was achieved with 0.2 g L^(-1) catalyst and 20 mmol L^(-1) H_(2)O_(2) within 90 min.We demonstrated that 5%C–CuFe_(2)O_(4) catalyst in the presence of H_(2)O_(2) was significantly efficient for TCH degradation under the near-neutral pH(5–9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS M€ossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H_(2)O_(2) to generate·OH and·O_(2)^(-).Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C–O–Cu and C–O–Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.
基金the National Key R&D Program of China(No.2018YFB1502201)the Guangdong Basic and Applied Basic Research Foundation,China(No.2020A1515010551).
文摘For present solid oxide fuel cells(SOFCs),rapid performance degradation is observed in the initial aging process,and the dis-cussion of the degradation mechanism necessitates quantitative analysis.Herein,focused ion beam-scanning electron microscopy was em-ployed to characterize and reconstruct the ceramic microstructures of SOFC anodes.The lattice Boltzmann method(LBM)simulation of multiphysical and electrochemical processes in the reconstructed models was performed.Two samples collected from industrial-size cells were characterized,including a reduced reference cell and a cell with an initial aging process.Statistical parameters of the reconstructed microstructures revealed a significant decrease in the active triple-phase boundary and Ni connectivity in the aged cell compared with the reference cell.The LBM simulation revealed that activity degradation is dominant compared with microstructural degradation during the initial aging process,and the electrochemical reactions spread to the support layer in the aged cell.The microstructural and activity de-gradations are attributed to Ni migration and coarsening.
基金supported by Shanghai Rising-Star Program(No.22QA1403900)the National Natural Science Foundation of China(No.71804106)the Noncarbon Energy Conversion and Utilization Institute under the Shanghai Class IV Peak Disciplinary Development Program.
文摘Cascading faults have been identified as the primary cause of multiple power outages in recent years.With the emergence of integrated energy systems(IES),the conventional approach to analyzing power grid cascading faults is no longer appropriate.A cascading fault analysis method considering multi-energy coupling characteristics is of vital importance.In this study,an innovative analysis method for cascading faults in integrated heat and electricity systems(IHES)is proposed.It considers the degradation characteristics of transmission and energy supply com-ponents in the system to address the impact of component aging on cascading faults.Firstly,degradation models for the current carrying capacity of transmission lines,the water carrying capacity and insulation performance of thermal pipelines,as well as the performance of energy supply equipment during aging,are developed.Secondly,a simulation process for cascading faults in the IHES is proposed.It utilizes an overload-dominated development model to predict the propagation path of cascading faults while also considering network islanding,electric-heating rescheduling,and load shedding.The propagation of cascading faults is reflected in the form of fault chains.Finally,the results of cascading faults under different aging levels are analyzed through numerical examples,thereby verifying the effectiveness and rationality of the proposed model and method.
基金Supported by the National Natural Science Foundation of China (Grant No. 20407005)the Hi-Tech Research and Development Program of China (Grant No. 2004AA649290)
文摘Zn-doped titanium oxide (TiO2) nanotubes electrode was prepared on a titanium plate by direct anodic oxidation and immersing method in sequence. Field emission scanning electron microscopy (FESEM) showed that the Zn-doped TiO2 nanotubes were well aligned and organized into high density uniform arrays with diameter ranging from 50 to 90 nm. The length and the thickness were about 200 and 15 nm respectively. TiO2 anatase phase was identified by X-ray diffraction (XRD). X-ray photoelectronspec-troscopy (XPS) indicated that Zn ions were mainly located on the surface of TiO2 nanotubes in form of ZnO clusters. Compared with TiO2 nanotubes electrode,about 20 nm red shift in the spectrum of UV-vis absorption was observed. The degradation of pentachlorophenol (PCP) in aqueous solution under the same condition (initial concentration of PCP: 20 mg/L; concentration of Na2SO4: 0.01 mol/L and pH: 7.03) was carried out using Zn-doped TiO2 nanotubes electrode and TiO2 nanotubes electrode. The degradation rates of PCP using Zn-doped TiO2 nanotubes electrode were found to be twice and 5.8 times as high as that using TiO2 nanotubes electrode by UV radiation (400 μw/cm2) and visible light radiation (4500 μw/cm2),respectively. 73.5% of PCP was removed using Zn-doped TiO2 nanotubes electrode against 48.5% removed using TiO2 nanotubes electrode in 120 min under UV radiation. While under visible light radiation,the degradation efficiency of PCP was 18.4% using Zn-doped TiO2 nano-tubes electrode against 3.2% using TiO2 nanotubes electrode in 120 min. The optimum concentration of Zn doping was found to be 0.909%. The PCP degradation efficiencies of the 10 repeated experiments by Zn-doped TiO2 nanotubes electrode were rather stable with the deviation within 3.0%.
基金supported by the National Natural Science Foundation of China (Nos. 21277134, 21107103)the State Key Laboratory of Environmental, Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences
文摘TiO_2 nanotube(Ti NT) electrodes anodized in fluorinated organic solutions were successfully prepared on Ti sheets. Field-emission scanning electron microscopy(FE-SEM) and X-ray diffraction(XRD) were performed to characterize the TiNT electrodes. The linear voltammetry results under irradiation showed that the TiNT electrode annealed at 450°C presented the highest photoelectrochemical activity. By combining photocatalytic with electrochemical process, a significantly synergetic effect on ammonia degradation was observed with Na_2SO_4 as supporting electrolyte at pH 10.7. Furthermore, the photoelectrocatalytic efficiency on the ammonia degradation was greatly enhanced in presence of chloride ions without the limitation of pH. The degradation rate was improved by 14.8 times reaching 4.98 × 10^(-2) min^(-1) at pH 10.7 and a faster degradation rate of 6.34 × 10^(-2) min^(-1)was obtained at pH 3.01. The in situ photoelectrocatalytic generated active chlorine was proposed to be responsible for the improved efficiency. On the other hand, an enhanced degradation of ammonia using TiNT electrode fabricated in fluorinated organic solution was also confirmed compared to TiNT electrode anodized in fluorinated water solution and TiO_2 film electrode fabricated by sol–gel method. Finally, the effect of chloride concentration was also discussed.
