With the growing concern about the water environment,the advanced oxidation process of persulfate activation assisted by photocatalysis has attracted considerable attention to decompose dissolved organic micropollutan...With the growing concern about the water environment,the advanced oxidation process of persulfate activation assisted by photocatalysis has attracted considerable attention to decompose dissolved organic micropollutants.In this work,to overcome the drawbacks of the photocatalytic activity reduction caused by the photo-corrosion of non-stoichiometric BiO_(2–x),a novel material with amorphous FeOOH in situ grown on layered BiO_(2–x) to form a core-shell structure similar to popcorn chicken-like morphology was produced in two simple and environmentally beneficial steps.Through a series of degradation activity tests of hybrid materials under different conditions,the as-prepared materials exhibited remarkable degradation activity and stability toward tetracycline in the FeOOH@BiO_(2–x)/Vis/PS system due to the synergism of photocatalysis and persulfate activation.The results of XRD,SEM,TEM,XPS,FTIR,and BET show that the loading of FeOOH increases the specific surface area and active sites appreciably;the heterogeneous structure formed by FeOOH and BiO_(2–x) is more favorable to the effective separation of photogenerated carriers.The optimal degradation conditions were at a catalyst addition of 0.7 g·L^(–1),a persulfate concentration of 1.0 g·L^(–1),and an initial pH of 4.5,at which the degradation rate could reach 94.7%after 90 min.The influence of typical inorganic anions on degradation was also examined.ESR studies and radical quenching experiments revealed that·OH,SO_(4)^(-)·,and·O_(2)^(-)were the principal active species generated during the degradation of tetracycline.The results of the 1,10-phenanthroline approach proved that the effect of dissolved iron ions on the tetracycline degradation was limited,and the interfacial reaction that occurs on the active sites on the material's surface was a critical factor.This work provides a novel method for producing efficient broad-spectrum Bismuth-based composite photocatalysts and photocatalytic-activated persulfate synergistic degradation of tetracycline.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 Fe...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
TiO_(2) nanobelts and Co_(3)O_(4)/TiO_(2) catalytic materials were prepared using the hydrothermal method.The cat-alyst was characterized by X-ray diffraction,scanning electron microscopy,transmission electron microsc...TiO_(2) nanobelts and Co_(3)O_(4)/TiO_(2) catalytic materials were prepared using the hydrothermal method.The cat-alyst was characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray electron spectroscopy,and fluorescence spectroscopy.At room temperature,with a relative humidity of 50.0%,the total gas flow rate of 1.0 L·min-1,the space velocity of 1.05×10^(4) h^(-1),and toluene volume concentration of 25.0µL·L^(-1),two 6 W vacuum ultraviolet lamps were used as light sources to catalyze,degrade,and mineralize toluene.The results show that the prepared catalyst is in the shape of nano-ribbons.The loading of Co_(3)O_(4) inhibits the recombina-tion of photogenerated electrons and holes and can effectively improve the catalytic performance.The Co_(3)O_(4)/TiO_(2) with a load of 6.0%Co_(3)O_(4) has the best catalytic effect.When N2 was used as a carrier gas,the degradation rate of tol-uene was only 34.7%.The toluene degradation is mainly due to the photolysis of vacuum ultraviolet light.When air was used as a carrier gas,O_(3) was produced.The Co_(3)O_(4)/TiO_(2) with a load of 6.0%and vacuum ultraviolet synergistical-ly promote toluene degradation.The highest degradation rate of toluene was 91.7%and the mineralization rate was 74.6%.The degradation rate of toluene was 2.6 times that of nitrogen as a carrier gas.展开更多
Plasma-catalysis is considered as one of the most promising technologies for antibiotic degradation in water.In the plasma-catalytic system,one of the factors affecting the degradation effect is the performance of the...Plasma-catalysis is considered as one of the most promising technologies for antibiotic degradation in water.In the plasma-catalytic system,one of the factors affecting the degradation effect is the performance of the photocatalyst,which is usually restricted by the rapid recombination of electrons and holes as well as narrow light absorption range.In this research,a photocatalyst g-C_(3)N_(4)/TiO_(2) was prepared and coupled with gas-liquid discharge(GLD)to degrade tetracycline(TC).The performance was examined,and the degradation pathways and mechanisms were studied.Results show that a 90%degradation rate is achieved in the GLD with g-C_(3)N_(4)/TiO_(2) over a 10 min treatment.Increasing the pulse voltage is conducive to increasing the degradation rate,whereas the addition of excessive g-C_(3)N_(4)/TiO_(2) tends to precipitate agglomerates,resulting in a poor degradation efficiency.The redox properties of the g-C_(3)N_(4)/TiO_(2) surface promote the generation of oxidizing active species(H2O2,O3)in solution.Radical quenching experiments showed that·OH,hole(h^(+)),play important roles in the TC degradation by the discharge with g-C_(3)N_(4)/TiO_(2).Two potential degradation pathways were proposed based on the intermediates.The toxicity of tetracycline was reduced by treatment in the system.Furthermore,the g-C_(3)N_(4)/TiO_(2) composites exhibited excellent recoverability and stability.展开更多
Efficient and convenient treatment of industrial dyeing wastewater is of great significance to guarantee human and animal health.This work presented the enhanced catalytic activity at pH 3.0 of laccase immobilized on ...Efficient and convenient treatment of industrial dyeing wastewater is of great significance to guarantee human and animal health.This work presented the enhanced catalytic activity at pH 3.0 of laccase immobilized on amino-functionalized ZnFe_(2)O_(4) nanoparticles(ZnFe_(2)O_(4)-laccase)and its application for the degradation of textile dyes.Due to the existence of a large number of oxygen vacancies on the surface of the ZnFe_(2)O_(4) nanoparticles,negative ions accumulated on the magnetic carriers,which resulted in a harsh optimal pH value of the ZnFe_(2)O_(4)-laccase.Laccase activity assays revealed that the ZnFe_(2)O_(4)-laccase possessed superior pH and thermal stabilities,excellent reusability,and noticeable organic solvent tolerance.Meanwhile,the ZnFe_(2)O_(4) laccase presented efficient and sustainable degradation of high concentrations of textile dyes.The initial decoloration efficiencies of malachite green(MG),brilliant green(BG),azophloxine,crystal violet(CV),reactive blue 19(RB19),and procion red MX-5B were approximately 99.1%,95.0%,93.3%,87.4%,86.1%,and 85.3%,respectively.After 10 consecutive reuses,the degradation rates of the textile dyes still maintained about 98.2%,92.5%,83.2%,81.5%,79.8%and 65.9%,respectively.The excellent dye degradation properties indicate that the ZnFe_(2)O_(4)-laccase has a technical application in high concentrations of dyestuff treatment.展开更多
High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of th...High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications.展开更多
In this work,Ag/Bi_(5)O_(7)I nanocomposite was prepared and firstly applied in piezo/photocatalytic reduction of N2 to NH3 and methyl orange(MO)degradation.Bi_(5)O_(7)I was synthesized via a hydrothermal-calcination m...In this work,Ag/Bi_(5)O_(7)I nanocomposite was prepared and firstly applied in piezo/photocatalytic reduction of N2 to NH3 and methyl orange(MO)degradation.Bi_(5)O_(7)I was synthesized via a hydrothermal-calcination method and shows nanorods morphology.Ag nanoparticles(NPs)were photo deposited on the Bi_(5)O_(7)I nanorods as electron trappers to improve the spatial separation of charge carriers,which was confirmed via XPS,TEM,and electronic chemical analyses.The catalytic test indicates that Bi_(5)O_(7)I presents the piezoelectric-like behavior,while the loading of Ag NPs can strengthen the character.Under ultrasonic vibration,the optimal Ag/Bi_(5)O_(7)I presents high efficiency in MO degradation.The degradation rate is determined to be 0.033 min1,which is 4.7 folds faster than that of Bi_(5)O_(7)I.The Ag/Bi_(5)O_(7)I also presents a high performance in piezocatalytic N2 fixation.The piezocatalytic NH3 generation rate reaches 65.4 μmol L^(-1)g^(-1)h^(-1)with water as a hole scavenger.The addition of methanol can hasten the piezoelectric catalytic reaction.Interestingly,when ultrasonic vibration and light irradiation simultaneously act on the Ag/Bi_(5)O_(7)I catalyst,higher performance in NH3 generation and MO degradation is observed.However,due to the weak adhesion of Ag NPs,some Ag NPs would fall off from the Bi_(5)O_(7)I surface under long-term ultrasonic vibration,which would greatly reduce the piezoelectric catalytic performance.This result indicates that a strong binding force is required when preparing the piezoelectric composite catalyst.The current work provides new insights for the development of highly efficient catalysts that can use multiple energies.展开更多
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
A series of MoS_(2)-modified CuO(CuO/MoS_(2))heterostructures were successfully fabricated.The photodegradation properties of organic dyes were explored in detail under visible light.The photocatalytic results demonst...A series of MoS_(2)-modified CuO(CuO/MoS_(2))heterostructures were successfully fabricated.The photodegradation properties of organic dyes were explored in detail under visible light.The photocatalytic results demonstrate that the CuO/MoS_(2)-3 heterostructure delivers superior degradation rates towards methyl violet dye(MV)and rhodamine B(RhB),reaching 99.8%and 95.3%within 30 min,respectively.The decent photodegradation activity is due to improved visible light adsorption and faster transfer of electron-hole pairs.The radical trapping experiments show that superoxide radicals(O_(2)^(-))and holes(h+)are the main active species in the removal of MV.Furthermore,the CuO/MoS_(2)-3 composite possesses the prominent stability and recyclability.This work offers a highly sustainable technique for designing a high-efficiency photocatalyst to remove environmental pollutants.展开更多
Photocatalysis is an environmentally friendly and energy-saving technology, which can effectively remove persistent dangerous pollutants in the water. Pitifully, optical absorption capacity and carrier separation have...Photocatalysis is an environmentally friendly and energy-saving technology, which can effectively remove persistent dangerous pollutants in the water. Pitifully, optical absorption capacity and carrier separation have become major bottlenecks for marvelous photocatalytic performance of photocatalysts.Herein, to address these issue, Nanodiamonds/yolk-shell ZnFe_(2)O_(4) spheres(NDs/ZFO) nanocomposites were successfully constructed via a facile two-step of solvothermal and calcination methods. The synthesized optimal NDs/ZFO-10 nanocomposite exhibits superior photocatalytic degradation activity of antibiotic under visible light, approximately 85% of the total tetracycline(TC) is degraded, and this photocatalyst shows durable cycling stability. This stems from two aspects of refinement: improvement of light absorption capacity and photo-induced charges migration and separation. In addition, the NDs/ZFO composite photocatalyst features excellent magnetic recovery capability, facilitating the recovery of photocatalyst in industry. This study opens a new chapter in the combination of NDs with magnetic materials, and deepens the understanding of the application of NDs modified composite photocatalysts.展开更多
The effect of N_(2)discharge products on cyclohexane degradation over a MnO_(2)/γ-Al_(2)O_(3)catalyst has been evaluated by feeding N_(2)discharge products to the catalyst using a specially designed dielectric barrie...The effect of N_(2)discharge products on cyclohexane degradation over a MnO_(2)/γ-Al_(2)O_(3)catalyst has been evaluated by feeding N_(2)discharge products to the catalyst using a specially designed dielectric barrier discharge reactor.At a reaction temperature of 100℃,the cyclohexane conversion increased from 2.46%(without N_(2)discharge products)to 26.3%(with N_(2)discharge products).N-and O-containing by-product(3,4-dehydroproline)was found on the catalyst surface using gas chromatograph-mass spectrometry identification,in which C=N–C and C=N–H bonds were also confirmed from x-ray photoelectron spectroscopy analysis results.Operando analysis results using diffuse reflectance infrared Fourier transform spectroscopy revealed that N atoms can react with surface H_(2)O possibly to NH and OH reactive species that have reactivities to promote CO oxidation to CO_(2).The mechanism of N-atom-driven cyclohexane degradation to CO and CO_(2)is proposed.展开更多
Trifunctional Cu-mesh/Cu_(2)O@FeO nanoarrays heterostructure is designed and fabricated by integrating CuCu_(2)O@FeO nanoarrays onto Cu-mesh(CM)via an in situ growth and phase transformation process.It is successfully...Trifunctional Cu-mesh/Cu_(2)O@FeO nanoarrays heterostructure is designed and fabricated by integrating CuCu_(2)O@FeO nanoarrays onto Cu-mesh(CM)via an in situ growth and phase transformation process.It is successfully applied to efficiently mitigate the antibiotic pollution,including degradation of antibiotics,inactivation of antibiotic-resistant bacteria(ARB),and damage of antibiotics resistance genes(ARGs).Under visible-light irradiation,CM/CuCu_(2)O@FeO nanoarrays exhibit a superior degradation efficiency on antibiotics(e.g.,up to 99%in 25 min for tetracycline hydrochloride,TC),due to the generated reactive oxygen species(ROS),especially the dominant·O^(2−).It can fully inactivate E.coli(HB101)with initial number of~108 CFU mL^(−1) in 10 min,which is mainly attributed to the synergistic effects of 1D nanostructure,dissolved metal ions,and generated ROS.Meanwhile,it is able to damage ARGs after 180 min of photodegradation,including tetA(vs TC)of 3.3 log 10,aphA(vs kanamycin sulfate,KAN)of 3.4 log 10,and tnpA(vs ampicillin,AMP)of 4.4 log 10,respectively.This work explores a green way for treating antibiotic pollution under visible light.展开更多
The crystal form of TiO_2 is a crucial focus of research on the photocatalytic degradation of gaseous pollutants by TiO_2-based composite photocatalysts. To explore the synergistic effect of mixed crystalline TiO_2 on...The crystal form of TiO_2 is a crucial focus of research on the photocatalytic degradation of gaseous pollutants by TiO_2-based composite photocatalysts. To explore the synergistic effect of mixed crystalline TiO_2 on gaseous organic-pollutant photocatalytic degradation, we synthesized a series of TiO_2 nanoparticles with controllable phase ratios. We explored the role of the TiO_2 phase ratio on the photocatalytic activity and degradation pathway in the photodegradation of 2-propanol(IPA). We estimated the crystallite size and crystal proportions of anatase and rutile by X-ray diffraction. We used the Brunauer-Emmett-Teller method to calculate the specific surface area and Fourier transform infrared spectroscopy to characterize the surface chemistry of the samples. Our results show the photocatalytic activities of pure anatase and the sample with 8.6% rutile to be much better than those of the samples with a phase junction and pure rutile. As such, anatase is the better option for the study of photodegradation design and preparation of gas-phase organic pollutants.展开更多
We report the construction of a graphene/tourmaline/TiO2(G/T/TiO2)composite system with enhanced charge‐carrier separation,and therefore enhanced photocatalytic properties,based on tailoring the surface‐charged stat...We report the construction of a graphene/tourmaline/TiO2(G/T/TiO2)composite system with enhanced charge‐carrier separation,and therefore enhanced photocatalytic properties,based on tailoring the surface‐charged state of graphene and/or by introducing an external electric field arising from tourmaline.A simple two‐step hydrothermal method was used to synthesize G/T/TiO2composites and poly(diallyldimethylammonium chloride)‐G/T/TiO2composites.In the photocatalytic degradation of2‐propanol(IPA),the catalytic activity of the composite containing negatively charged graphene was higher than of the composite containing positively charged graphene.The highest acetone evolution rate(223?mol/h)was achieved using the ternary composite with the optimum composition,i.e.,G0.5/T5/TiO2(0.5wt%graphene and5wt%tourmaline).The involvement of tourmaline and graphene in the composite is believed to facilitate the separation and transportation of electrons and holes photogenerated in TiO2.This synergetic effect could account for the enhanced photocatalytic activity of the G/T/TiO2composite.A mechanistic study indicated that O2??radicals and holes were the main reactive oxygen species in photocatalytic degradation of IPA.展开更多
In order to explore the reaction mechanism of Fe^3+ and the mineralization effect of the micropollutant, Fe^3+ assisted photocatalytic oxidation of sulfadiazine (SD) in the TiO2 suspended solution is investigated....In order to explore the reaction mechanism of Fe^3+ and the mineralization effect of the micropollutant, Fe^3+ assisted photocatalytic oxidation of sulfadiazine (SD) in the TiO2 suspended solution is investigated. The effect of Fe^3+ participation, the degradation kinetics of SD, the effect of SD mineralization and the possible mechanism of Fe^3+ participation in TiO2 suspension are analyzed by adding FeCl3, taking samples at a given time and determining the SD concentration. Results indicate that the degradation of SD catalyzed by TiO2/ Fe^3+ is faster than that catalyzed by TiO2 or Fe^3+ separately. The photocatalytic degradation of SD follows the pseudo-first- order kinetics model in a range of 20 to 80 mg/L of initial concentration. The mineralization rate of SD can be enhanced by the addition of Fe^3+ in the TiO2 suspended solution. The mechanism of the rapid degradation of SD is proposed, which indicates that Fe^3+ adsorbed on the surface of TiO2 particles acts as an electron acceptor. The amount of recombining electronhole pairs decreases, and the amount of hydroxyl radicals increases. The increased hydroxyl radical strengthens the degradation of SD in the TiO2/Fe^3+ suspended solution.展开更多
ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. Th...ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photoeatalytic activities of the as-prepared samples were evaluated by the photocatalytic degradation of methyl orange and inactivation of Escherichia coli in suspension under the irradiation of the simulated sunlight. The effects of compositions, calcination temperatures, concentration ofphotocatalysts and light source on the photocatalytic activities were systematically studied. The results show that when the concentration of ZnO/ZnA1204 photocatalyst with the starting Zn to Al molar ratio of 1:1.5 calcined at 600 ℃ is 1.0 g/L, the maximum photocatalytic degradation rate of 98.5% can be obtained in 50 min under the irradiation of the simulated sunlight. Under the same conditions, an inactivation rate of 99.8% for E.coli is achieved in 60 min.展开更多
基金supported by the National Key Research and Development Program of China(2019YFC1904100)the National Natural Science Foundation of China(21503144)+3 种基金the Science and Technology Innovation Project for Students of Hebei Province(22E50174D)the Science and Technology Project of Hebei Education Department(QN2021047)the Program of Hebei Vocational University of Industry and Technology(dxs202207,ZY202401)the Key Program of Natural Science of Hebei Province(B2020209017).
文摘With the growing concern about the water environment,the advanced oxidation process of persulfate activation assisted by photocatalysis has attracted considerable attention to decompose dissolved organic micropollutants.In this work,to overcome the drawbacks of the photocatalytic activity reduction caused by the photo-corrosion of non-stoichiometric BiO_(2–x),a novel material with amorphous FeOOH in situ grown on layered BiO_(2–x) to form a core-shell structure similar to popcorn chicken-like morphology was produced in two simple and environmentally beneficial steps.Through a series of degradation activity tests of hybrid materials under different conditions,the as-prepared materials exhibited remarkable degradation activity and stability toward tetracycline in the FeOOH@BiO_(2–x)/Vis/PS system due to the synergism of photocatalysis and persulfate activation.The results of XRD,SEM,TEM,XPS,FTIR,and BET show that the loading of FeOOH increases the specific surface area and active sites appreciably;the heterogeneous structure formed by FeOOH and BiO_(2–x) is more favorable to the effective separation of photogenerated carriers.The optimal degradation conditions were at a catalyst addition of 0.7 g·L^(–1),a persulfate concentration of 1.0 g·L^(–1),and an initial pH of 4.5,at which the degradation rate could reach 94.7%after 90 min.The influence of typical inorganic anions on degradation was also examined.ESR studies and radical quenching experiments revealed that·OH,SO_(4)^(-)·,and·O_(2)^(-)were the principal active species generated during the degradation of tetracycline.The results of the 1,10-phenanthroline approach proved that the effect of dissolved iron ions on the tetracycline degradation was limited,and the interfacial reaction that occurs on the active sites on the material's surface was a critical factor.This work provides a novel method for producing efficient broad-spectrum Bismuth-based composite photocatalysts and photocatalytic-activated persulfate synergistic degradation of tetracycline.
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.
文摘TiO_(2) nanobelts and Co_(3)O_(4)/TiO_(2) catalytic materials were prepared using the hydrothermal method.The cat-alyst was characterized by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,X-ray electron spectroscopy,and fluorescence spectroscopy.At room temperature,with a relative humidity of 50.0%,the total gas flow rate of 1.0 L·min-1,the space velocity of 1.05×10^(4) h^(-1),and toluene volume concentration of 25.0µL·L^(-1),two 6 W vacuum ultraviolet lamps were used as light sources to catalyze,degrade,and mineralize toluene.The results show that the prepared catalyst is in the shape of nano-ribbons.The loading of Co_(3)O_(4) inhibits the recombina-tion of photogenerated electrons and holes and can effectively improve the catalytic performance.The Co_(3)O_(4)/TiO_(2) with a load of 6.0%Co_(3)O_(4) has the best catalytic effect.When N2 was used as a carrier gas,the degradation rate of tol-uene was only 34.7%.The toluene degradation is mainly due to the photolysis of vacuum ultraviolet light.When air was used as a carrier gas,O_(3) was produced.The Co_(3)O_(4)/TiO_(2) with a load of 6.0%and vacuum ultraviolet synergistical-ly promote toluene degradation.The highest degradation rate of toluene was 91.7%and the mineralization rate was 74.6%.The degradation rate of toluene was 2.6 times that of nitrogen as a carrier gas.
基金supported by National Natural Science Foundation of China(Nos.52277151 and 51907088)Innovative Talents Team Project of‘Six Talent Peaks’of Jiangsu Province(No.TD-JNHB-006).
文摘Plasma-catalysis is considered as one of the most promising technologies for antibiotic degradation in water.In the plasma-catalytic system,one of the factors affecting the degradation effect is the performance of the photocatalyst,which is usually restricted by the rapid recombination of electrons and holes as well as narrow light absorption range.In this research,a photocatalyst g-C_(3)N_(4)/TiO_(2) was prepared and coupled with gas-liquid discharge(GLD)to degrade tetracycline(TC).The performance was examined,and the degradation pathways and mechanisms were studied.Results show that a 90%degradation rate is achieved in the GLD with g-C_(3)N_(4)/TiO_(2) over a 10 min treatment.Increasing the pulse voltage is conducive to increasing the degradation rate,whereas the addition of excessive g-C_(3)N_(4)/TiO_(2) tends to precipitate agglomerates,resulting in a poor degradation efficiency.The redox properties of the g-C_(3)N_(4)/TiO_(2) surface promote the generation of oxidizing active species(H2O2,O3)in solution.Radical quenching experiments showed that·OH,hole(h^(+)),play important roles in the TC degradation by the discharge with g-C_(3)N_(4)/TiO_(2).Two potential degradation pathways were proposed based on the intermediates.The toxicity of tetracycline was reduced by treatment in the system.Furthermore,the g-C_(3)N_(4)/TiO_(2) composites exhibited excellent recoverability and stability.
基金supported by the National Natural Science Foundation of China(21471002)Scientific Research Projects of Universities in Anhui Province(2022AH040135)+1 种基金Natural Science Research Project for Anhui Universities(KJ2021A0509)Anhui Natural Science Foundation(2208085MC83).
文摘Efficient and convenient treatment of industrial dyeing wastewater is of great significance to guarantee human and animal health.This work presented the enhanced catalytic activity at pH 3.0 of laccase immobilized on amino-functionalized ZnFe_(2)O_(4) nanoparticles(ZnFe_(2)O_(4)-laccase)and its application for the degradation of textile dyes.Due to the existence of a large number of oxygen vacancies on the surface of the ZnFe_(2)O_(4) nanoparticles,negative ions accumulated on the magnetic carriers,which resulted in a harsh optimal pH value of the ZnFe_(2)O_(4)-laccase.Laccase activity assays revealed that the ZnFe_(2)O_(4)-laccase possessed superior pH and thermal stabilities,excellent reusability,and noticeable organic solvent tolerance.Meanwhile,the ZnFe_(2)O_(4) laccase presented efficient and sustainable degradation of high concentrations of textile dyes.The initial decoloration efficiencies of malachite green(MG),brilliant green(BG),azophloxine,crystal violet(CV),reactive blue 19(RB19),and procion red MX-5B were approximately 99.1%,95.0%,93.3%,87.4%,86.1%,and 85.3%,respectively.After 10 consecutive reuses,the degradation rates of the textile dyes still maintained about 98.2%,92.5%,83.2%,81.5%,79.8%and 65.9%,respectively.The excellent dye degradation properties indicate that the ZnFe_(2)O_(4)-laccase has a technical application in high concentrations of dyestuff treatment.
基金Project supported by the National Natural Science Foundation of China(Nos.12302278,U2241267,12172155,and 11932008)the Fundamental Research Funds for the Central Universities of China(No.lzujbky-2022-48)the Natural Science Foundation of Gansu Province of China(No.24JRRA473)。
文摘High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications.
基金supported by Nature Science Foundation of Zhejiang Province(Grant No.LY20B030004).
文摘In this work,Ag/Bi_(5)O_(7)I nanocomposite was prepared and firstly applied in piezo/photocatalytic reduction of N2 to NH3 and methyl orange(MO)degradation.Bi_(5)O_(7)I was synthesized via a hydrothermal-calcination method and shows nanorods morphology.Ag nanoparticles(NPs)were photo deposited on the Bi_(5)O_(7)I nanorods as electron trappers to improve the spatial separation of charge carriers,which was confirmed via XPS,TEM,and electronic chemical analyses.The catalytic test indicates that Bi_(5)O_(7)I presents the piezoelectric-like behavior,while the loading of Ag NPs can strengthen the character.Under ultrasonic vibration,the optimal Ag/Bi_(5)O_(7)I presents high efficiency in MO degradation.The degradation rate is determined to be 0.033 min1,which is 4.7 folds faster than that of Bi_(5)O_(7)I.The Ag/Bi_(5)O_(7)I also presents a high performance in piezocatalytic N2 fixation.The piezocatalytic NH3 generation rate reaches 65.4 μmol L^(-1)g^(-1)h^(-1)with water as a hole scavenger.The addition of methanol can hasten the piezoelectric catalytic reaction.Interestingly,when ultrasonic vibration and light irradiation simultaneously act on the Ag/Bi_(5)O_(7)I catalyst,higher performance in NH3 generation and MO degradation is observed.However,due to the weak adhesion of Ag NPs,some Ag NPs would fall off from the Bi_(5)O_(7)I surface under long-term ultrasonic vibration,which would greatly reduce the piezoelectric catalytic performance.This result indicates that a strong binding force is required when preparing the piezoelectric composite catalyst.The current work provides new insights for the development of highly efficient catalysts that can use multiple energies.
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the National Natural Science Foundation of China(51572185)Natural Science Foundation of Shanxi Province(202203021211158 and 20210302123173)the Key Research and Developmen program of Shanxi Province(International Cooperation,201903D421079)for the financial support.
文摘A series of MoS_(2)-modified CuO(CuO/MoS_(2))heterostructures were successfully fabricated.The photodegradation properties of organic dyes were explored in detail under visible light.The photocatalytic results demonstrate that the CuO/MoS_(2)-3 heterostructure delivers superior degradation rates towards methyl violet dye(MV)and rhodamine B(RhB),reaching 99.8%and 95.3%within 30 min,respectively.The decent photodegradation activity is due to improved visible light adsorption and faster transfer of electron-hole pairs.The radical trapping experiments show that superoxide radicals(O_(2)^(-))and holes(h+)are the main active species in the removal of MV.Furthermore,the CuO/MoS_(2)-3 composite possesses the prominent stability and recyclability.This work offers a highly sustainable technique for designing a high-efficiency photocatalyst to remove environmental pollutants.
基金the founding support from the National Natural Science Foundation of China(21906072 and 22006057)the Natural Science Foundation of Jiangsu Province(BK20190982)+2 种基金Henan Postdoctoral Foundation(202003013)“Doctor of Mass entrepreneurship and innovation” Project in Jiangsu ProvinceOpen Fund for Hebei Province Key Laboratory of Sustained Utilization & Development of Water Recourse(HSZYL2021003)。
文摘Photocatalysis is an environmentally friendly and energy-saving technology, which can effectively remove persistent dangerous pollutants in the water. Pitifully, optical absorption capacity and carrier separation have become major bottlenecks for marvelous photocatalytic performance of photocatalysts.Herein, to address these issue, Nanodiamonds/yolk-shell ZnFe_(2)O_(4) spheres(NDs/ZFO) nanocomposites were successfully constructed via a facile two-step of solvothermal and calcination methods. The synthesized optimal NDs/ZFO-10 nanocomposite exhibits superior photocatalytic degradation activity of antibiotic under visible light, approximately 85% of the total tetracycline(TC) is degraded, and this photocatalyst shows durable cycling stability. This stems from two aspects of refinement: improvement of light absorption capacity and photo-induced charges migration and separation. In addition, the NDs/ZFO composite photocatalyst features excellent magnetic recovery capability, facilitating the recovery of photocatalyst in industry. This study opens a new chapter in the combination of NDs with magnetic materials, and deepens the understanding of the application of NDs modified composite photocatalysts.
基金National Natural Science Foundation of China(No.12075037)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_2873)Research and Application Service Platform Project of API Manufacturing Environmental Protection and Safety Technology in China(No.2020-0107-3-1).
文摘The effect of N_(2)discharge products on cyclohexane degradation over a MnO_(2)/γ-Al_(2)O_(3)catalyst has been evaluated by feeding N_(2)discharge products to the catalyst using a specially designed dielectric barrier discharge reactor.At a reaction temperature of 100℃,the cyclohexane conversion increased from 2.46%(without N_(2)discharge products)to 26.3%(with N_(2)discharge products).N-and O-containing by-product(3,4-dehydroproline)was found on the catalyst surface using gas chromatograph-mass spectrometry identification,in which C=N–C and C=N–H bonds were also confirmed from x-ray photoelectron spectroscopy analysis results.Operando analysis results using diffuse reflectance infrared Fourier transform spectroscopy revealed that N atoms can react with surface H_(2)O possibly to NH and OH reactive species that have reactivities to promote CO oxidation to CO_(2).The mechanism of N-atom-driven cyclohexane degradation to CO and CO_(2)is proposed.
基金This work was financially sup-ported by the National Natural Science Foundation of China(NSFC Nos:22171212,21771140,51771138,51979194)International Corporation Project of Shanghai Committee of Science and Technology by China(No.21160710300)International Exchange Grant(IEC/NSFC/201078)through Royal Society UK and NSFC.
文摘Trifunctional Cu-mesh/Cu_(2)O@FeO nanoarrays heterostructure is designed and fabricated by integrating CuCu_(2)O@FeO nanoarrays onto Cu-mesh(CM)via an in situ growth and phase transformation process.It is successfully applied to efficiently mitigate the antibiotic pollution,including degradation of antibiotics,inactivation of antibiotic-resistant bacteria(ARB),and damage of antibiotics resistance genes(ARGs).Under visible-light irradiation,CM/CuCu_(2)O@FeO nanoarrays exhibit a superior degradation efficiency on antibiotics(e.g.,up to 99%in 25 min for tetracycline hydrochloride,TC),due to the generated reactive oxygen species(ROS),especially the dominant·O^(2−).It can fully inactivate E.coli(HB101)with initial number of~108 CFU mL^(−1) in 10 min,which is mainly attributed to the synergistic effects of 1D nanostructure,dissolved metal ions,and generated ROS.Meanwhile,it is able to damage ARGs after 180 min of photodegradation,including tetA(vs TC)of 3.3 log 10,aphA(vs kanamycin sulfate,KAN)of 3.4 log 10,and tnpA(vs ampicillin,AMP)of 4.4 log 10,respectively.This work explores a green way for treating antibiotic pollution under visible light.
基金supported by the National Natural Science Foundation of China (Nos.21406164,21466035,51203111)the National Basic Research Program of China("973" program,Nos.2012CB720100,2014CB239300)
文摘The crystal form of TiO_2 is a crucial focus of research on the photocatalytic degradation of gaseous pollutants by TiO_2-based composite photocatalysts. To explore the synergistic effect of mixed crystalline TiO_2 on gaseous organic-pollutant photocatalytic degradation, we synthesized a series of TiO_2 nanoparticles with controllable phase ratios. We explored the role of the TiO_2 phase ratio on the photocatalytic activity and degradation pathway in the photodegradation of 2-propanol(IPA). We estimated the crystallite size and crystal proportions of anatase and rutile by X-ray diffraction. We used the Brunauer-Emmett-Teller method to calculate the specific surface area and Fourier transform infrared spectroscopy to characterize the surface chemistry of the samples. Our results show the photocatalytic activities of pure anatase and the sample with 8.6% rutile to be much better than those of the samples with a phase junction and pure rutile. As such, anatase is the better option for the study of photodegradation design and preparation of gas-phase organic pollutants.
基金supported by the National Basic Research Program of China (973 Program,2014CB239300)the National Natural Science Foundation of China (51572191)the Natural Science Foundation of Tianjin (13JCYBJC16600)~~
文摘We report the construction of a graphene/tourmaline/TiO2(G/T/TiO2)composite system with enhanced charge‐carrier separation,and therefore enhanced photocatalytic properties,based on tailoring the surface‐charged state of graphene and/or by introducing an external electric field arising from tourmaline.A simple two‐step hydrothermal method was used to synthesize G/T/TiO2composites and poly(diallyldimethylammonium chloride)‐G/T/TiO2composites.In the photocatalytic degradation of2‐propanol(IPA),the catalytic activity of the composite containing negatively charged graphene was higher than of the composite containing positively charged graphene.The highest acetone evolution rate(223?mol/h)was achieved using the ternary composite with the optimum composition,i.e.,G0.5/T5/TiO2(0.5wt%graphene and5wt%tourmaline).The involvement of tourmaline and graphene in the composite is believed to facilitate the separation and transportation of electrons and holes photogenerated in TiO2.This synergetic effect could account for the enhanced photocatalytic activity of the G/T/TiO2composite.A mechanistic study indicated that O2??radicals and holes were the main reactive oxygen species in photocatalytic degradation of IPA.
基金The Priority Academic Program Development of Jiangsu Higher Education Institutions (No. 1105007001 )the Ph. D. Programs Foundation of Ministry of Education of China (No. 20100092120018)the Natural Science Foundation of Jiangsu Province (No. BK2009453)
文摘In order to explore the reaction mechanism of Fe^3+ and the mineralization effect of the micropollutant, Fe^3+ assisted photocatalytic oxidation of sulfadiazine (SD) in the TiO2 suspended solution is investigated. The effect of Fe^3+ participation, the degradation kinetics of SD, the effect of SD mineralization and the possible mechanism of Fe^3+ participation in TiO2 suspension are analyzed by adding FeCl3, taking samples at a given time and determining the SD concentration. Results indicate that the degradation of SD catalyzed by TiO2/ Fe^3+ is faster than that catalyzed by TiO2 or Fe^3+ separately. The photocatalytic degradation of SD follows the pseudo-first- order kinetics model in a range of 20 to 80 mg/L of initial concentration. The mineralization rate of SD can be enhanced by the addition of Fe^3+ in the TiO2 suspended solution. The mechanism of the rapid degradation of SD is proposed, which indicates that Fe^3+ adsorbed on the surface of TiO2 particles acts as an electron acceptor. The amount of recombining electronhole pairs decreases, and the amount of hydroxyl radicals increases. The increased hydroxyl radical strengthens the degradation of SD in the TiO2/Fe^3+ suspended solution.
基金Project(21271071)supported by the National Natural Science Foundation of ChinaProject(21306041)supported by the National Natural Science Young Foundation of China
文摘ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photoeatalytic activities of the as-prepared samples were evaluated by the photocatalytic degradation of methyl orange and inactivation of Escherichia coli in suspension under the irradiation of the simulated sunlight. The effects of compositions, calcination temperatures, concentration ofphotocatalysts and light source on the photocatalytic activities were systematically studied. The results show that when the concentration of ZnO/ZnA1204 photocatalyst with the starting Zn to Al molar ratio of 1:1.5 calcined at 600 ℃ is 1.0 g/L, the maximum photocatalytic degradation rate of 98.5% can be obtained in 50 min under the irradiation of the simulated sunlight. Under the same conditions, an inactivation rate of 99.8% for E.coli is achieved in 60 min.