Singlet oxygen(^(1)O_(2))is recognized as one of the most effective and selective oxygen agents.However,the explorative study of photocatalysts(PCs)for effective ^(1)O_(2)-based photocatalytic oxidation remains challe...Singlet oxygen(^(1)O_(2))is recognized as one of the most effective and selective oxygen agents.However,the explorative study of photocatalysts(PCs)for effective ^(1)O_(2)-based photocatalytic oxidation remains challenging and critical.In this study,a novel donor-acceptor metal-organic framework(D-A MOF)has been developed by engineering the D-A system,which was then evaluated as a photocatalyst for ^(1)O_(2)-based oxidation.By regulating the donor component of the D-A systematic framework,the MOF(B1)exhibits delayed fluorescence(DF)behavior with a reduced singlet-triplet gap.Given the significantly improved electron transfer behavior in combination with an efficient energy transfer process,the optimal B1 demonstrates remarkable activity toward ^(1)O_(2)generation under suitable photoexcitation conditions.Therefore,it can be utilized for the photocatalytic oxidation of 1,5-dioxynaphthalene(1,5-DHN)to Juglone,achieving the highest yield(conversion>99%at 25℃ in 30 min)and selectivity among all previously reported MOF photocatalysts.展开更多
Successfully generating reactive oxygen species(ROS)in a targeted and efficient manner for the detoxification of chlorinated organic pollutants(CPs)is a significant and demanding challenge.Herein,we present an in-situ...Successfully generating reactive oxygen species(ROS)in a targeted and efficient manner for the detoxification of chlorinated organic pollutants(CPs)is a significant and demanding challenge.Herein,we present an in-situ photoreduction strategy to fabricate a composite of palladium(Pd)nanoparticles anchored few-layer carbon nitride nanosheets(Pd-CN).This innovative Pd-CN is then leveraged to activate peroxymonosulfate(PMS)in pursuit of our objective.The incorporation of Pd nanoparticles enhances PMS absorption and targets its terminal oxygen,thereby aiding in the cleavage of the O-O bond.This process generates crucial intermediates,including adsorbed hydroxyl radicals(*OH)and adsorbed atomic oxygen(O*),which are essential for the production of ^(1)O_(2).Consequently,the Pd-CN catalyst demonstrates strong preference for ^(1)O_(2) generation during the PMS activation process,successfully degrading over 95%of pollutants such as 4-chlorophenol(4-CP),2,4-dichlorophenol(2,4-DCP),and 2,4,6-trichlorophenol(2,4,6-TCP)within just 20 min.Additionally,the catalyst exhibits total organic carbon(TOC)removal rates ranging from 49.4%to 31.4%,while the rates for de-chlorination fall between 68.6%and 72.7%.A subsequent continuous-flow treatment experiment has confirmed the application potential of this system,demonstrating consistent catalytic activity for up to 8 h.This promising technique presents an efficient strategy for addressing the high toxicity of chlorinated organic pollutants in contaminated water.展开更多
Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and of...Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and offering the highest theoretical energy density(~3.5 k Wh kg^(-1))among discussed candidates.Contributing to the poor cycle life of currently reported Li-O_(2)cells is singlet oxygen(1O_(2))formation,inducing parasitic reactions,degrading key components,and severely deteriorating cell performance.Here,we harness the chirality-induced spin selectivity effect of chiral cobalt oxide nanosheets(Co_(3)O_(4)NSs)as cathode materials to suppress 1O_(2)in Li-O_(2)batteries for the first time.Operando photoluminescence spectroscopy reveals a 3.7-fold and 3.23-fold reduction in 1O_(2)during discharge and charge,respectively,compared to conventional carbon paperbased cells,consistent with differential electrochemical mass spectrometry results,which indicate a near-theoretical charge-to-O_(2)ratio(2.04 e-/O_(2)).Density functional theory calculations demonstrate that chirality induces a peak shift near the Fermi level,enhancing Co 3d-O 2p hybridization,stabilizing reaction intermediates,and lowering activation barriers for Li_(2)O_(2)formation and decomposition.These findings establish a new strategy for improving the stability and energy efficiency of sustainable Li-O_(2)batteries,abridging the current gap to commercialization.展开更多
Conventional hyperspectral cameras cascade lenses and spectrometers to acquire the spectral datacube,which forms the fundamental framework for hyperspectral imaging.However,this cascading framework involves tradeoffs ...Conventional hyperspectral cameras cascade lenses and spectrometers to acquire the spectral datacube,which forms the fundamental framework for hyperspectral imaging.However,this cascading framework involves tradeoffs among spectral and imaging performances when the system is driven toward miniaturization.Here,we propose a spectral singlet lens that unifies optical imaging and computational spectrometry functions,enabling the creation of minimalist,miniaturized and high-performance hyperspectral cameras.As a paradigm,we capitalize on planar liquid crystal optics to implement the proposed framework,with each liquid-crystal unit cell acting as both phase modulator and electrically tunable spectral filter.Experiments with various targets show that the resulting millimeter-scale hyperspectral camera exhibits both high spectral fidelity(>95%)and high spatial resolutions(~1.7 times the diffraction limit).The proposed“two-in-one”framework can resolve the conflicts between spectral and imaging resolutions,which paves a practical pathway for advancing hyperspectral imaging systems toward miniaturization and portable applications.展开更多
Singlet oxygen(^(1)O_(2)),as the primary reactive oxygen species in photodynamic therapy,can effectively induce excessive oxidative stress to ablate tumors and kill germs in clinical treatment.However,monitoring endog...Singlet oxygen(^(1)O_(2)),as the primary reactive oxygen species in photodynamic therapy,can effectively induce excessive oxidative stress to ablate tumors and kill germs in clinical treatment.However,monitoring endogenous^(1)O_(2)is greatly challenging due to its extremely short lifetime and high reactivity in biological condition.Herein,we report an ultra-high signal-to-ratio near-infrared chemiluminescent probe(DCMCy)for the precise detection of endogenous^(1)O_(2)during photodynamic therapy(PDT).The methoxy moiety was removed from enolether unit in DCM-Cy to suppress the potential self-photooxidation reaction,thus greatly eliminating the photoinduced background signals during PDT.Additionally,the compact cyclobutane modification of DCM-Cy resulted in a significant 6-fold increase in cell permeability compared to conventional adamantane-dioxane probes.Therefore,our“step-by-step”strategy for DCM-Cy addressed the limitations of traditional chemiluminescent(CL)probes for^(1)O_(2),enabling effectively tracking of endogenous^(1)O_(2)level changes in living cells,pathogenic bacteria and mice in PDT.展开更多
Different from reversible agonist-stimulated receptor activation,singlet oxygen oxidation activates permanently G protein-coupled receptor(GPCR)cholecystokinin 1(CCK1R)in type II photodynamic action,with soluble photo...Different from reversible agonist-stimulated receptor activation,singlet oxygen oxidation activates permanently G protein-coupled receptor(GPCR)cholecystokinin 1(CCK1R)in type II photodynamic action,with soluble photosensitizer dyes(sulphonated aluminum phthalocyanine,λmax 675 nm)or genetically encoded protein photosensitizers(KillerRedλmax 585 nm;mini singlet oxygen generatorλmax 450 nm),together with a pulse of light(37 mW/cm2,1-2 minutes).Three lines of evidence shed light on the mechanism of GPCR activated by singlet oxygen(GPCR-ABSO):(1)CCK1R is quantitatively converted from dimer to monomer;(2)Transmembrane domain 3,a pharmacophore for permanent photodynamic CCK1R activation,can be transplanted to non-susceptible M3 acetylcholine receptor;and(3)Larger size of disordered region in intracellular loop 3 correlates with higher sensitivity to photodynamic CCK1R activation.GPCR-ABSO will add to the arsenal of engineered designer GPCR such as receptors activated solely by synthetic ligands and designer receptors exclusively activated by designer drugs,but show some clear advantages:Enhanced selectivity(double selectivity of localized photosensitizer and light illumination),long-lasting activation with no need for repeated drug administration,antagonist-binding site remains intact when needed,ease to apply to multiple GPCR.This type of permanent photodynamic activation may be applied to functional proteins other than GPCR.展开更多
Common activations of sulfite(S(Ⅳ))-based advanced oxidation processes(AOPs)utilized metal ions and oxides as catalysts,which are constrained by challenges in catalyst recovery,inadequate stability,and susceptibility...Common activations of sulfite(S(Ⅳ))-based advanced oxidation processes(AOPs)utilized metal ions and oxides as catalysts,which are constrained by challenges in catalyst recovery,inadequate stability,and susceptibility to secondary pollution in application.Calcium sulfite(CaSO_(3)),one of the byproducts of flue gas desulfurization,is of interest in AOPs because of its ability to slowly release S(Ⅳ),low toxicity,and costeffectiveness.Therefore,a heterogenous activator,molybdenum carbide(Mo_(2)C)was selected to stimulate Ca SO3for typical antibiotic elimination.Benefiting from the dissociation form of HSO_(3^(-))from CaSO_(3)and improved electron transfer of Mo_(2)C at pH 6,the simulated target metronidazole(MTZ)can be removed by 85.65%with rate constant of 0.02424 min^(-1)under near-neutral circumstance.The combining determinations of quenching test,electron spin resonance spectrum,and reactive species probe demonstrated singlet oxygen(^(1)O_(2))and sulfate radicals played leading role for MTZ decontamination.Characterization and theoretical calculation suggested the alteration of Mo valence state drove the activation of S(Ⅳ),and revealed that dissolved oxygen promoted the adsorption of HSO_(3^(-))on the surface of Mo_(2)C,then facilitating production of^(1)O_(2).The favorable stability and applicability for Mo_(2)C/CaSO_(3)process indicated an applied prospect in actual pharmaceutical wastewater.展开更多
Singlet oxygen(^(1)O_(2)),as an electrophilic oxidant,is essential for the selective water decontamination of pollutants from water.Herein,we showcase a high-performing electrocatalytic filtration system composed of c...Singlet oxygen(^(1)O_(2)),as an electrophilic oxidant,is essential for the selective water decontamination of pollutants from water.Herein,we showcase a high-performing electrocatalytic filtration system composed of carbon nanotubes functionalized with CoFe alloy nanoparticles(CoFeCNT)to selectively facilitate the electrochemical activation of O_(2)to^(1)O_(2).Benefiting from the prominently featured bimetal active sites of CoFeCNT,nearly complete production of^(1)O_(2)is achieved by the electrocatalytic activation of O_(2).Additionally,the proposed system exhibits a consistent pollutant removal efficiency>90%in a flow-through reactor over 48 h of continuous operation without a noticeable decline in performance,highlighting the dependable stability of the system for practical applications.The flow-through configuration demonstrates a striking 8-fold enhancement in tetracycline oxidation compared to a conventional batch reactor.This work provides a molecular level understanding of the oxygen reduction reaction,showing promising potential for the selective removal of emerging organic contaminants from water.展开更多
Harnessing the redox potential of biochar to activate airborne O_(2)for contaminant removal is challenging.In this study,ferrihydrite(Fh)modified the boron(B),nitrogen(N)co-doped biochars(BCs)composites(Fh/B(n)NC)were...Harnessing the redox potential of biochar to activate airborne O_(2)for contaminant removal is challenging.In this study,ferrihydrite(Fh)modified the boron(B),nitrogen(N)co-doped biochars(BCs)composites(Fh/B(n)NC)were developed for enhancing the degradation of a model pollutant,tetracycline(TC),merely by airborne O_(2).Fh/B(3)NC showed excellent O_(2)activation activity for efficient TC degradation with a apparent TC degradation rate of 5.54,6.88,and 22.15 times that of B(3)NC,Fh,and raw BCs,respectively,where 1O_(2)and H_(2)O_(2)were identified as the dominant ROS for TC degradation.The B incorporation into the carbon lattice of Fh/B(3)NC promoted the generation of electron donors,sp2 C and the reductive B species,hence boosting Fe(III)reduction and 1O_(2)generation.O_(2)adsorption was enhanced due to the positively charged adsorption sites(C-B+and N-C+).And 1O_(2)was generated via Fe(II)catalyzed low-efficient successive one-electron transfer(O_(2)→O_(2)·−→1O_(2),H_(2)O_(2)),as well as biochar catalyzed high-efficient two-electron transfer(O_(2)→H_(2)O_(2)→1O_(2))that does not involve.O_(2)−as the intermediate.Moreover,Fh/B,N co-doped biochar showed a wide pH range,remarkable anti-interference capabilities,and effective detoxification.These findings shed new light on the development of environmentally benign BCs materials capable of degradading organic pollutants.展开更多
The authors regret<During the submission process,Hongxiang Zhang and Honggen Peng served as the first and the second corresponding author,respectively.The original manuscript submitted for this paper also listed tw...The authors regret<During the submission process,Hongxiang Zhang and Honggen Peng served as the first and the second corresponding author,respectively.The original manuscript submitted for this paper also listed two co-corresponding authors(Hongxiang Zhang and Honggen Peng).But the corresponding author of Honggen Peng was omitted in the final published manuscript.So,we apply to designate Honggen Peng(penghonggen@ncu.edu.cn)as the second co-corresponding author and the corresponding unit is“a,b">.展开更多
Reactive oxygen species(ROS),including singlet oxygen(^(1)O_(2)),hydroxyl radicals(·OH),and superoxide anions(O_(2)^(·-)),are highly reactive molecules that play central roles in many chemical,biological,and...Reactive oxygen species(ROS),including singlet oxygen(^(1)O_(2)),hydroxyl radicals(·OH),and superoxide anions(O_(2)^(·-)),are highly reactive molecules that play central roles in many chemical,biological,and environmental processes due to their strong oxidative power[1].Generating ROS in a controlled manner under mild conditions is essential for achieving selective oxidation reactions.Light-driven methods are especially appealing for this purpose,as they offer precise control over where and when ROS are produced.展开更多
A singlet diatomic molecule naturally carries doubly degenerate ±Λ states when the projection of the total electronic angular momentum onto the internuclear axis is nonzero. These doubly degenerate states contri...A singlet diatomic molecule naturally carries doubly degenerate ±Λ states when the projection of the total electronic angular momentum onto the internuclear axis is nonzero. These doubly degenerate states contribute equally in conventional measurements and are thus treated the same in corresponding simulations. In this study, we demonstrate that in resonant excitation by intense laser pulses, the doubly degenerate ±Λ states must be clearly identified. This is exemplified in the X^(1)Σ → A^(1)Π transition of CO molecules. This distinction becomes especially important in the case of circularly polarized radiation. We attribute this phenomenon to the interference of electron-rotational pathways in the strong-field coupled transition with the ±Λ-state of the excited Π state. This research sheds light on the fundamental aspects of intense laser-molecule interactions when extending conventional theories.展开更多
[Objective ]The aim of this study was to improve the photostability of pho-tosensitizers. [Method] 2,5-Diphenylthiophene and 2,5-dithienylethynylthiophene were synthesized by replacing thiophene rings of α-terthienyl...[Objective ]The aim of this study was to improve the photostability of pho-tosensitizers. [Method] 2,5-Diphenylthiophene and 2,5-dithienylethynylthiophene were synthesized by replacing thiophene rings of α-terthienyl （α-T） with benzene rings. Photoactivated activities on Spodoptera litura （SL） cells, singlet oxygen with UV and photostability of photosensitizers were investigated. [Result] The cytotoxicity of pho-tosensitizer 2,5-diphenylthiophene on SL cells was 0.22 and 0.16 μg/ml after treat-ment for 24 and 48 h, respectively, while that of 2,5-dithienylethynylthiophene on SL cells was 0.06 and 0.04 μg/ml. Singlet oxygen of 2,5-diphenylthiophene and 2,5-dithienylethynylthiophene was 1.047 5, 1.529 4 μg/mmol under UV, respectively. Degradation dynamic equations of 2,5-diphenylthiophene and 2,5-dithienylethynylthio-phene in methanol were Ct= 5.227 1e-0.006 1t, Ct= 5.084 2e-0.097 3t and half life was 111.79, 7.12 h. [Conclusion] Photosensitizer 2,5-diphenylthiophene has high singlet oxygen production ability, and high photoactivated cytotoxicity on SL cells under UV. Moreover, 2,5-diphenylthiophene has overcome the deficiency of photoactivated in-secticides, which is not applied directly in field because it degrades quickly in the environment.展开更多
Based on a cosmological model without singularity, a possible structure of the universe is presented. It is proved that there must simultaneously be two sorts of symmetry breaking in the universe. The universe is comp...Based on a cosmological model without singularity, a possible structure of the universe is presented. It is proved that there must simultaneously be two sorts of symmetry breaking in the universe. The universe is composed of infinite s-cosmic islands, infinite v-cosmic islands and infinite transition zone. The existing and changing forms of the cosmic islands must be diverse. The cosmological principle holds only approximately within a cosmic island. No information can be exchanged between an s-cosmic island and an adjacent v-cosmic island so that every observer thinks his cosmic island to be the whole universe. It is possible that some cosmic islands are contracting, some cosmic islands are expanding, and other cosmic islands are stable for a time. But the universe as a whole is always invariable and contains all possible existing forms of matter. To give a possible explanation for orphan quasars. To predict some characteristics of contracting large and huge black holes in a cosmic island. The characteristics of the light coming from the contracting huge black holes are that the intensity of the light is huge relatively to their distance, the red shifts are huge, the distribution of the huge red shifts and the orphan quasars are anisotropic, and luminescence spectrum is very wide.展开更多
A flow system was set up to measure the quenching probability ~ of O2（1△g） on various O2- adsorbed metal surfaces including Cu, Cr, Ni, and Ag. increased with both the duration of the experiment and the O2（1△g）...A flow system was set up to measure the quenching probability ~ of O2（1△g） on various O2- adsorbed metal surfaces including Cu, Cr, Ni, and Ag. increased with both the duration of the experiment and the O2（1△g） concentration. After several hours evacuation to a few Pa, γ can return to its original value. A deactivation mechanism of O2（1△g） is suggested by considering first the weak chemisorption of O2（1△g） on the surface adsorption sites, followed by the near resonant energy transfer between the gas phase O2（1△g） and surface O2（1△g）. A phenomenological model in accord with the experimental fact has been proposed together with relevant kinetic equations.展开更多
Magnetic CuO nanosheet(Mag-CuO), as a cheap, stable, efficient and easily separated peroxymonosulfate(PMS) activator, was prepared by a simple one-step precipitation method for the removal of organic compounds from sa...Magnetic CuO nanosheet(Mag-CuO), as a cheap, stable, efficient and easily separated peroxymonosulfate(PMS) activator, was prepared by a simple one-step precipitation method for the removal of organic compounds from salt-containing wastewater.The experiments showed that the removal efficiencies of various organic pollutants including Acid Orange 7, Methylene Blue, Rhodamine B and atrazine in a high-salinity system(0.2 mol/L Na2SO4) with the Mag-CuO/PMS process were 95.81%, 74.57%, 100% and 100%,respectively.Meanwhile, Mag-CuO still maintained excellent catalytic activity in other salt systems including one or more salt components(NaCl, NaNO3, Na2HPO4, NaHCO3).A radical-quenching study and electron paramagnetic resonance analysis confirmed that singlet oxygen(1O2) was the dominant reactive oxygen species for the oxidation of organic pollutants in high-salinity systems, which is less susceptible to hindrance by background constituents in wastewater than radicals(·OH or SO4·-).The surface hydroxylation of the catalyst and catalytic redox cycle including Cu and Fe are responsible for the generation of1O2.The developed Mag-CuO catalyst shows good application prospects for the removal of organic pollutants from saline wastewater.展开更多
This work was designed to explore the characteristics of photodegradation of herbicides in the copper-polluted water body. The results showed that Cu（Ⅱ） alone could induce a photo Fenton-like reaction to enhance th...This work was designed to explore the characteristics of photodegradation of herbicides in the copper-polluted water body. The results showed that Cu（Ⅱ） alone could induce a photo Fenton-like reaction to enhance the degradation of atrazine, in which hydroxyl radical （.OH） was a main active species. Humic acids restrained atrazine degradation, nevertheless, when introducing Cu（Ⅱ）, the photodegradation was accelerated, in which singlet oxygen （102） replaced -OH acting as the prevailing species. A feasible mechanism for the photochemical process was also proposed, which is helpful for better understanding the environmental photochemistry of atrazine in the copper-polluted water.展开更多
Nonradical reaction driven by peroxymonosulfate(PMS)based advanced oxidation pro-cesses has drawn widespread attention in water treatment due to their inherent advantages,but the degradation behavior and mechanism of ...Nonradical reaction driven by peroxymonosulfate(PMS)based advanced oxidation pro-cesses has drawn widespread attention in water treatment due to their inherent advantages,but the degradation behavior and mechanism of organic pollutants are still unclear.In this study,the performance,intermediates,mechanism and toxicity of tetracycline(TC)degra-dation were thoroughly examined in the constructed magnetic nitrogen-doped porous car-bon/peroxymonosulfate(Co-N/C-PMS)system.The results showed that 85.4%of TC could be removed within 15 min when Co-N/C and PMS was simultaneously added and the degra-dation rate was enhanced by 3.4 and 14.7 folds compared with Co-N/C or PMS alone,re-spectively.Moreover,the performance of Co-N/C was superior to that of most previously reported catalysts.Many lines of evidence indicated that Co-N/C-PMS system was a singlet oxygen-dominated nonradical reaction,which was less interfered by pH and water compo-nents,and displayed high adaptability to actual water bodies.Subsequently,the degrada-tion process was elaborated on the basis of three-dimensional excitation-emission matrix spectra and liquid chromatography-mass spectrometry.At last,the toxicity of treated TC was greatly reduced by using microalgae Coelastrella sp.as ecological indicator.This study provides a promising approach based on singlet oxygen-dominated nonradical reaction for eliminating TC in water treatment.展开更多
A series of Sr-doped BiFeO3 perovskites(Bi1-xSrxFeO3,BSFO)fabricated via sol-gel method was applied as peroxydisulfate(PDS)activator for ciprofloxacin(CIP)degradation.Various technologies were used to characterize the...A series of Sr-doped BiFeO3 perovskites(Bi1-xSrxFeO3,BSFO)fabricated via sol-gel method was applied as peroxydisulfate(PDS)activator for ciprofloxacin(CIP)degradation.Various technologies were used to characterize the morphology and physicochemical features of prepared BSFO samples and the results indicated that Sr was successfully inserted into the perovskites lattice.The catalytic performance of BiFeO3 was significantly boosted by strontium doping.Specifically,Bi0.9Sr0.1FeO3(0.1 BSFO)exhibited the highest catalytic performance for PDS activation to remove CIP,where 95%of CIP(10 mg/L)could be degraded with the addition of 1 g/L 0.1 BSFO and 1 mmol/L PDS within 60 min.Moreover,0.1 BSFO displayed high reusability and stability with lower metal leaching.Weak acidic condition was preferred to neutral and alkaline conditions in 0.1 BSFO/PDS system.The boosted catalytic performance can be interpreted as the lower oxidation state of Fe and the existence of affluent oxygen vacancies generated by Sr doping,that induced the formation of singlet oxygen(^1O_(2))which was confirmed as the dominant reactive species by radical scavenging studies and electron spin resonance(ESR)tests.The catalytic oxidation mechanism related to major ^1O_(2) and minor free radicals was proposed.Current study opens a new avenue to develop effective A-site modified perovskite and expands their application for PDS activation in wastewater remediation.展开更多
Magnetic Cuº/Fe_(3)O_(4)submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)and the degradation of organic pollutants.The...Magnetic Cuº/Fe_(3)O_(4)submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)and the degradation of organic pollutants.The as-prepared magnetic Cu/Fe_(3)O_(4)submicron composites were composed of Cu°and FesO+crystals and had an average size of approximately 220 nm.The Cu/FesO+composites could efficiently catalyze the activation of PMS to generate singlet oxygen,and thusinduced the rapid degradation of rhodamine B,methylene blue,orange 1l,phenol and 4-chlorophenol.The use of 0.1 g/L of the Cu°/Fe_(3)O_(4)composites induced the complete removal of rhodamine B(20μmol/L)in 15 min,methylene blue(20μmol/L)in 5 min,orange II(20μmol/L)in 10 min,phenol(0.1 mmol/L)in 30 min and 4-chlorophenol(0.1 mmol/L)in 15 min with an initial pH value of 7.0 and a PMS concentration of 0.5 mmol/L.The total organic carbon(TOC)removal higher than 85%for all of these five pollutants was obtained in 30 min when the PMS concentration was 2.5 mmol/L.The rate of degradation was considerably higher than that obtained with Cuªor FezO4 particles alone.The enhanced catalytic activity of the Cu°/Fe_(3)O_(4)composites in the activation of PMS was attributed to the synergistic effect of the Cu*and Fe_(3)O_(4)crystals in the composites.Singlet oxygen was identi-fied as the primary reactive oxygen species responsible for pollutant degradation by electron spin resonance and radical quenching experiments.A possible mechanism for the activation of PMS by Cu°/Fe_(3)O_(4)composites is proposed as electron transfer from the organic pollutants to PMS induces the activation of PMS to generate 10z,which induces the degradation of the organic pollutants.As a magnetic catalyst,the Cu°/Fe_(3)O_(4)composites were easily recovered by magnetic separation,and exhibited excellent stability over five successive degradation cycles.The present study provides a facile and green heterogeneous catalysis method for the oxidative removal of organic pollutants.展开更多
基金supported by the National Key R&D Program of China(2022YFA1503301)the National Natural Science Foundation of China(NSFC)(22375104,22035003,22201143,22371134)+1 种基金the China Postdoctoral Science Foundation(2022M711699)the Haihe Laboratory of Sustainable Chemical Transformations(YYJC202101)。
文摘Singlet oxygen(^(1)O_(2))is recognized as one of the most effective and selective oxygen agents.However,the explorative study of photocatalysts(PCs)for effective ^(1)O_(2)-based photocatalytic oxidation remains challenging and critical.In this study,a novel donor-acceptor metal-organic framework(D-A MOF)has been developed by engineering the D-A system,which was then evaluated as a photocatalyst for ^(1)O_(2)-based oxidation.By regulating the donor component of the D-A systematic framework,the MOF(B1)exhibits delayed fluorescence(DF)behavior with a reduced singlet-triplet gap.Given the significantly improved electron transfer behavior in combination with an efficient energy transfer process,the optimal B1 demonstrates remarkable activity toward ^(1)O_(2)generation under suitable photoexcitation conditions.Therefore,it can be utilized for the photocatalytic oxidation of 1,5-dioxynaphthalene(1,5-DHN)to Juglone,achieving the highest yield(conversion>99%at 25℃ in 30 min)and selectivity among all previously reported MOF photocatalysts.
基金supported by the Natural Science Foundation of Hebei Province(No.B2024203026)the Yanzhao Golden Platform Talent Project(Education Platform)of Hebei Province(No.HJYB202517)+1 种基金the National Natural Science Foundation of China(Nos.U22A20403,22006128)the Open Foundation of MOE Key Laboratory of Resources and Environmental System Optimization,College of Environmental Science and Engineering,North China Electric Power University(No.KLRE-KF202308).
文摘Successfully generating reactive oxygen species(ROS)in a targeted and efficient manner for the detoxification of chlorinated organic pollutants(CPs)is a significant and demanding challenge.Herein,we present an in-situ photoreduction strategy to fabricate a composite of palladium(Pd)nanoparticles anchored few-layer carbon nitride nanosheets(Pd-CN).This innovative Pd-CN is then leveraged to activate peroxymonosulfate(PMS)in pursuit of our objective.The incorporation of Pd nanoparticles enhances PMS absorption and targets its terminal oxygen,thereby aiding in the cleavage of the O-O bond.This process generates crucial intermediates,including adsorbed hydroxyl radicals(*OH)and adsorbed atomic oxygen(O*),which are essential for the production of ^(1)O_(2).Consequently,the Pd-CN catalyst demonstrates strong preference for ^(1)O_(2) generation during the PMS activation process,successfully degrading over 95%of pollutants such as 4-chlorophenol(4-CP),2,4-dichlorophenol(2,4-DCP),and 2,4,6-trichlorophenol(2,4,6-TCP)within just 20 min.Additionally,the catalyst exhibits total organic carbon(TOC)removal rates ranging from 49.4%to 31.4%,while the rates for de-chlorination fall between 68.6%and 72.7%.A subsequent continuous-flow treatment experiment has confirmed the application potential of this system,demonstrating consistent catalytic activity for up to 8 h.This promising technique presents an efficient strategy for addressing the high toxicity of chlorinated organic pollutants in contaminated water.
基金supported by Basic Science Research Program(Priority Research Institute)through the NRF of Korea funded by the Ministry of Education(2021R1A6A1A10039823)by the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education(2020R1A6C101B194)。
文摘Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and offering the highest theoretical energy density(~3.5 k Wh kg^(-1))among discussed candidates.Contributing to the poor cycle life of currently reported Li-O_(2)cells is singlet oxygen(1O_(2))formation,inducing parasitic reactions,degrading key components,and severely deteriorating cell performance.Here,we harness the chirality-induced spin selectivity effect of chiral cobalt oxide nanosheets(Co_(3)O_(4)NSs)as cathode materials to suppress 1O_(2)in Li-O_(2)batteries for the first time.Operando photoluminescence spectroscopy reveals a 3.7-fold and 3.23-fold reduction in 1O_(2)during discharge and charge,respectively,compared to conventional carbon paperbased cells,consistent with differential electrochemical mass spectrometry results,which indicate a near-theoretical charge-to-O_(2)ratio(2.04 e-/O_(2)).Density functional theory calculations demonstrate that chirality induces a peak shift near the Fermi level,enhancing Co 3d-O 2p hybridization,stabilizing reaction intermediates,and lowering activation barriers for Li_(2)O_(2)formation and decomposition.These findings establish a new strategy for improving the stability and energy efficiency of sustainable Li-O_(2)batteries,abridging the current gap to commercialization.
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFB2804700,2021YFA1202000 and 2021YFE0205800)National Natural Science Foundation of China(Grant Nos.12174292,62222507,and 62175101)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20212004)Fundamental Research Funds for the Central Universities(2042024kf1005).
文摘Conventional hyperspectral cameras cascade lenses and spectrometers to acquire the spectral datacube,which forms the fundamental framework for hyperspectral imaging.However,this cascading framework involves tradeoffs among spectral and imaging performances when the system is driven toward miniaturization.Here,we propose a spectral singlet lens that unifies optical imaging and computational spectrometry functions,enabling the creation of minimalist,miniaturized and high-performance hyperspectral cameras.As a paradigm,we capitalize on planar liquid crystal optics to implement the proposed framework,with each liquid-crystal unit cell acting as both phase modulator and electrically tunable spectral filter.Experiments with various targets show that the resulting millimeter-scale hyperspectral camera exhibits both high spectral fidelity(>95%)and high spatial resolutions(~1.7 times the diffraction limit).The proposed“two-in-one”framework can resolve the conflicts between spectral and imaging resolutions,which paves a practical pathway for advancing hyperspectral imaging systems toward miniaturization and portable applications.
基金supported by National Natural Science Foundation of China(Nos.32121005,22225805,22308101,and 32394001)Shanghai Science and Technology Innovation Action Plan(No.23J21901600)+2 种基金Innovation Program of Shanghai Municipal Education Commission,Shanghai Frontier Science Research Base of Optogenetic Techniques for Cell Metabolism(Shanghai Municipal Education Commission,No.2021 Sci&Tech 03-28)the China Postdoctoral Science Foundation(No.2021M701199)Natural Science Foundation of Shanghai(No.23ZR1416600).
文摘Singlet oxygen(^(1)O_(2)),as the primary reactive oxygen species in photodynamic therapy,can effectively induce excessive oxidative stress to ablate tumors and kill germs in clinical treatment.However,monitoring endogenous^(1)O_(2)is greatly challenging due to its extremely short lifetime and high reactivity in biological condition.Herein,we report an ultra-high signal-to-ratio near-infrared chemiluminescent probe(DCMCy)for the precise detection of endogenous^(1)O_(2)during photodynamic therapy(PDT).The methoxy moiety was removed from enolether unit in DCM-Cy to suppress the potential self-photooxidation reaction,thus greatly eliminating the photoinduced background signals during PDT.Additionally,the compact cyclobutane modification of DCM-Cy resulted in a significant 6-fold increase in cell permeability compared to conventional adamantane-dioxane probes.Therefore,our“step-by-step”strategy for DCM-Cy addressed the limitations of traditional chemiluminescent(CL)probes for^(1)O_(2),enabling effectively tracking of endogenous^(1)O_(2)level changes in living cells,pathogenic bacteria and mice in PDT.
基金Supported by the National Natural Science Foundation of China,No.32271278 and No.31971170.
文摘Different from reversible agonist-stimulated receptor activation,singlet oxygen oxidation activates permanently G protein-coupled receptor(GPCR)cholecystokinin 1(CCK1R)in type II photodynamic action,with soluble photosensitizer dyes(sulphonated aluminum phthalocyanine,λmax 675 nm)or genetically encoded protein photosensitizers(KillerRedλmax 585 nm;mini singlet oxygen generatorλmax 450 nm),together with a pulse of light(37 mW/cm2,1-2 minutes).Three lines of evidence shed light on the mechanism of GPCR activated by singlet oxygen(GPCR-ABSO):(1)CCK1R is quantitatively converted from dimer to monomer;(2)Transmembrane domain 3,a pharmacophore for permanent photodynamic CCK1R activation,can be transplanted to non-susceptible M3 acetylcholine receptor;and(3)Larger size of disordered region in intracellular loop 3 correlates with higher sensitivity to photodynamic CCK1R activation.GPCR-ABSO will add to the arsenal of engineered designer GPCR such as receptors activated solely by synthetic ligands and designer receptors exclusively activated by designer drugs,but show some clear advantages:Enhanced selectivity(double selectivity of localized photosensitizer and light illumination),long-lasting activation with no need for repeated drug administration,antagonist-binding site remains intact when needed,ease to apply to multiple GPCR.This type of permanent photodynamic activation may be applied to functional proteins other than GPCR.
基金the support received from the National Natural Science Foundation of China(No.51908485)the Central Guidance on Local Science and Technology Development Fund of Hebei Province(Nos.246Z3603G and 226Z3603G)。
文摘Common activations of sulfite(S(Ⅳ))-based advanced oxidation processes(AOPs)utilized metal ions and oxides as catalysts,which are constrained by challenges in catalyst recovery,inadequate stability,and susceptibility to secondary pollution in application.Calcium sulfite(CaSO_(3)),one of the byproducts of flue gas desulfurization,is of interest in AOPs because of its ability to slowly release S(Ⅳ),low toxicity,and costeffectiveness.Therefore,a heterogenous activator,molybdenum carbide(Mo_(2)C)was selected to stimulate Ca SO3for typical antibiotic elimination.Benefiting from the dissociation form of HSO_(3^(-))from CaSO_(3)and improved electron transfer of Mo_(2)C at pH 6,the simulated target metronidazole(MTZ)can be removed by 85.65%with rate constant of 0.02424 min^(-1)under near-neutral circumstance.The combining determinations of quenching test,electron spin resonance spectrum,and reactive species probe demonstrated singlet oxygen(^(1)O_(2))and sulfate radicals played leading role for MTZ decontamination.Characterization and theoretical calculation suggested the alteration of Mo valence state drove the activation of S(Ⅳ),and revealed that dissolved oxygen promoted the adsorption of HSO_(3^(-))on the surface of Mo_(2)C,then facilitating production of^(1)O_(2).The favorable stability and applicability for Mo_(2)C/CaSO_(3)process indicated an applied prospect in actual pharmaceutical wastewater.
基金supported by the Natural Science Foundation of Shanghai(No.23ZR1401300)the National Natural Science Foundation of China(No.52170068).
文摘Singlet oxygen(^(1)O_(2)),as an electrophilic oxidant,is essential for the selective water decontamination of pollutants from water.Herein,we showcase a high-performing electrocatalytic filtration system composed of carbon nanotubes functionalized with CoFe alloy nanoparticles(CoFeCNT)to selectively facilitate the electrochemical activation of O_(2)to^(1)O_(2).Benefiting from the prominently featured bimetal active sites of CoFeCNT,nearly complete production of^(1)O_(2)is achieved by the electrocatalytic activation of O_(2).Additionally,the proposed system exhibits a consistent pollutant removal efficiency>90%in a flow-through reactor over 48 h of continuous operation without a noticeable decline in performance,highlighting the dependable stability of the system for practical applications.The flow-through configuration demonstrates a striking 8-fold enhancement in tetracycline oxidation compared to a conventional batch reactor.This work provides a molecular level understanding of the oxygen reduction reaction,showing promising potential for the selective removal of emerging organic contaminants from water.
基金supported by the National Natural Science Foundation of China(No.U21A20293).
文摘Harnessing the redox potential of biochar to activate airborne O_(2)for contaminant removal is challenging.In this study,ferrihydrite(Fh)modified the boron(B),nitrogen(N)co-doped biochars(BCs)composites(Fh/B(n)NC)were developed for enhancing the degradation of a model pollutant,tetracycline(TC),merely by airborne O_(2).Fh/B(3)NC showed excellent O_(2)activation activity for efficient TC degradation with a apparent TC degradation rate of 5.54,6.88,and 22.15 times that of B(3)NC,Fh,and raw BCs,respectively,where 1O_(2)and H_(2)O_(2)were identified as the dominant ROS for TC degradation.The B incorporation into the carbon lattice of Fh/B(3)NC promoted the generation of electron donors,sp2 C and the reductive B species,hence boosting Fe(III)reduction and 1O_(2)generation.O_(2)adsorption was enhanced due to the positively charged adsorption sites(C-B+and N-C+).And 1O_(2)was generated via Fe(II)catalyzed low-efficient successive one-electron transfer(O_(2)→O_(2)·−→1O_(2),H_(2)O_(2)),as well as biochar catalyzed high-efficient two-electron transfer(O_(2)→H_(2)O_(2)→1O_(2))that does not involve.O_(2)−as the intermediate.Moreover,Fh/B,N co-doped biochar showed a wide pH range,remarkable anti-interference capabilities,and effective detoxification.These findings shed new light on the development of environmentally benign BCs materials capable of degradading organic pollutants.
文摘The authors regret<During the submission process,Hongxiang Zhang and Honggen Peng served as the first and the second corresponding author,respectively.The original manuscript submitted for this paper also listed two co-corresponding authors(Hongxiang Zhang and Honggen Peng).But the corresponding author of Honggen Peng was omitted in the final published manuscript.So,we apply to designate Honggen Peng(penghonggen@ncu.edu.cn)as the second co-corresponding author and the corresponding unit is“a,b">.
文摘Reactive oxygen species(ROS),including singlet oxygen(^(1)O_(2)),hydroxyl radicals(·OH),and superoxide anions(O_(2)^(·-)),are highly reactive molecules that play central roles in many chemical,biological,and environmental processes due to their strong oxidative power[1].Generating ROS in a controlled manner under mild conditions is essential for achieving selective oxidation reactions.Light-driven methods are especially appealing for this purpose,as they offer precise control over where and when ROS are produced.
基金supported by the National Natural Science Foundation of China(Grant No.12374238)the Postdoctoral Science Foundation of Shaanxi Province (Grant No.2024BSHSDZZ148)Ministry of Science and Higher Education of Russian Federation (Grant No.FSRZ 2023-0006)。
文摘A singlet diatomic molecule naturally carries doubly degenerate ±Λ states when the projection of the total electronic angular momentum onto the internuclear axis is nonzero. These doubly degenerate states contribute equally in conventional measurements and are thus treated the same in corresponding simulations. In this study, we demonstrate that in resonant excitation by intense laser pulses, the doubly degenerate ±Λ states must be clearly identified. This is exemplified in the X^(1)Σ → A^(1)Π transition of CO molecules. This distinction becomes especially important in the case of circularly polarized radiation. We attribute this phenomenon to the interference of electron-rotational pathways in the strong-field coupled transition with the ±Λ-state of the excited Π state. This research sheds light on the fundamental aspects of intense laser-molecule interactions when extending conventional theories.
基金Supported by Science and Technology Support Program of Jiangsu Province(Agricultural Project)(BE2012346)Science and Technology Projects for Social Development of Yangzhou City,China(2012110)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(13KJB210010)~~
文摘[Objective ]The aim of this study was to improve the photostability of pho-tosensitizers. [Method] 2,5-Diphenylthiophene and 2,5-dithienylethynylthiophene were synthesized by replacing thiophene rings of α-terthienyl （α-T） with benzene rings. Photoactivated activities on Spodoptera litura （SL） cells, singlet oxygen with UV and photostability of photosensitizers were investigated. [Result] The cytotoxicity of pho-tosensitizer 2,5-diphenylthiophene on SL cells was 0.22 and 0.16 μg/ml after treat-ment for 24 and 48 h, respectively, while that of 2,5-dithienylethynylthiophene on SL cells was 0.06 and 0.04 μg/ml. Singlet oxygen of 2,5-diphenylthiophene and 2,5-dithienylethynylthiophene was 1.047 5, 1.529 4 μg/mmol under UV, respectively. Degradation dynamic equations of 2,5-diphenylthiophene and 2,5-dithienylethynylthio-phene in methanol were Ct= 5.227 1e-0.006 1t, Ct= 5.084 2e-0.097 3t and half life was 111.79, 7.12 h. [Conclusion] Photosensitizer 2,5-diphenylthiophene has high singlet oxygen production ability, and high photoactivated cytotoxicity on SL cells under UV. Moreover, 2,5-diphenylthiophene has overcome the deficiency of photoactivated in-secticides, which is not applied directly in field because it degrades quickly in the environment.
文摘Based on a cosmological model without singularity, a possible structure of the universe is presented. It is proved that there must simultaneously be two sorts of symmetry breaking in the universe. The universe is composed of infinite s-cosmic islands, infinite v-cosmic islands and infinite transition zone. The existing and changing forms of the cosmic islands must be diverse. The cosmological principle holds only approximately within a cosmic island. No information can be exchanged between an s-cosmic island and an adjacent v-cosmic island so that every observer thinks his cosmic island to be the whole universe. It is possible that some cosmic islands are contracting, some cosmic islands are expanding, and other cosmic islands are stable for a time. But the universe as a whole is always invariable and contains all possible existing forms of matter. To give a possible explanation for orphan quasars. To predict some characteristics of contracting large and huge black holes in a cosmic island. The characteristics of the light coming from the contracting huge black holes are that the intensity of the light is huge relatively to their distance, the red shifts are huge, the distribution of the huge red shifts and the orphan quasars are anisotropic, and luminescence spectrum is very wide.
基金This work was supported by the National Natural Science Foundation of China （No.20703045） and the National Key Basic Research and Science Foundation （No.2007CBS15202）.
文摘A flow system was set up to measure the quenching probability ~ of O2（1△g） on various O2- adsorbed metal surfaces including Cu, Cr, Ni, and Ag. increased with both the duration of the experiment and the O2（1△g） concentration. After several hours evacuation to a few Pa, γ can return to its original value. A deactivation mechanism of O2（1△g） is suggested by considering first the weak chemisorption of O2（1△g） on the surface adsorption sites, followed by the near resonant energy transfer between the gas phase O2（1△g） and surface O2（1△g）. A phenomenological model in accord with the experimental fact has been proposed together with relevant kinetic equations.
基金supported by the National Water Pollution Control and Management Program of China (No.2017ZX07107002).
文摘Magnetic CuO nanosheet(Mag-CuO), as a cheap, stable, efficient and easily separated peroxymonosulfate(PMS) activator, was prepared by a simple one-step precipitation method for the removal of organic compounds from salt-containing wastewater.The experiments showed that the removal efficiencies of various organic pollutants including Acid Orange 7, Methylene Blue, Rhodamine B and atrazine in a high-salinity system(0.2 mol/L Na2SO4) with the Mag-CuO/PMS process were 95.81%, 74.57%, 100% and 100%,respectively.Meanwhile, Mag-CuO still maintained excellent catalytic activity in other salt systems including one or more salt components(NaCl, NaNO3, Na2HPO4, NaHCO3).A radical-quenching study and electron paramagnetic resonance analysis confirmed that singlet oxygen(1O2) was the dominant reactive oxygen species for the oxidation of organic pollutants in high-salinity systems, which is less susceptible to hindrance by background constituents in wastewater than radicals(·OH or SO4·-).The surface hydroxylation of the catalyst and catalytic redox cycle including Cu and Fe are responsible for the generation of1O2.The developed Mag-CuO catalyst shows good application prospects for the removal of organic pollutants from saline wastewater.
基金supported by the National Basic Research Program (973) of China (No. 2007CB407302)the New Century Excellent Talent Program of the Ministry of Education of China (2010)the Fundamental Research Funds for the Central Universities of China (No.DUT11ZD108)
文摘This work was designed to explore the characteristics of photodegradation of herbicides in the copper-polluted water body. The results showed that Cu（Ⅱ） alone could induce a photo Fenton-like reaction to enhance the degradation of atrazine, in which hydroxyl radical （.OH） was a main active species. Humic acids restrained atrazine degradation, nevertheless, when introducing Cu（Ⅱ）, the photodegradation was accelerated, in which singlet oxygen （102） replaced -OH acting as the prevailing species. A feasible mechanism for the photochemical process was also proposed, which is helpful for better understanding the environmental photochemistry of atrazine in the copper-polluted water.
基金This work was supported by the National Natural Science Foundation of China(Nos.51978178 and 51521006)the Department of Science and Technology of Guangdong Province of China(Nos.2019A1515012044 and 2021A1515011797)+3 种基金the International S&T Cooperation Program of China(No.2015DFG92750)the Maoming Municipal Bureau of Science and Technology of Guangdong of China(No.2018S0013)the Startup Fund of Guangdong University of Petrochemical Technology(No.2020rc041)the Shanghai Tongji Gao Tingyao Environmental Science&Technology Development Foundation.
文摘Nonradical reaction driven by peroxymonosulfate(PMS)based advanced oxidation pro-cesses has drawn widespread attention in water treatment due to their inherent advantages,but the degradation behavior and mechanism of organic pollutants are still unclear.In this study,the performance,intermediates,mechanism and toxicity of tetracycline(TC)degra-dation were thoroughly examined in the constructed magnetic nitrogen-doped porous car-bon/peroxymonosulfate(Co-N/C-PMS)system.The results showed that 85.4%of TC could be removed within 15 min when Co-N/C and PMS was simultaneously added and the degra-dation rate was enhanced by 3.4 and 14.7 folds compared with Co-N/C or PMS alone,re-spectively.Moreover,the performance of Co-N/C was superior to that of most previously reported catalysts.Many lines of evidence indicated that Co-N/C-PMS system was a singlet oxygen-dominated nonradical reaction,which was less interfered by pH and water compo-nents,and displayed high adaptability to actual water bodies.Subsequently,the degrada-tion process was elaborated on the basis of three-dimensional excitation-emission matrix spectra and liquid chromatography-mass spectrometry.At last,the toxicity of treated TC was greatly reduced by using microalgae Coelastrella sp.as ecological indicator.This study provides a promising approach based on singlet oxygen-dominated nonradical reaction for eliminating TC in water treatment.
基金the National Key Research and Development Program of China(Nos.2018YFD1100505,2019YFD1100201)。
文摘A series of Sr-doped BiFeO3 perovskites(Bi1-xSrxFeO3,BSFO)fabricated via sol-gel method was applied as peroxydisulfate(PDS)activator for ciprofloxacin(CIP)degradation.Various technologies were used to characterize the morphology and physicochemical features of prepared BSFO samples and the results indicated that Sr was successfully inserted into the perovskites lattice.The catalytic performance of BiFeO3 was significantly boosted by strontium doping.Specifically,Bi0.9Sr0.1FeO3(0.1 BSFO)exhibited the highest catalytic performance for PDS activation to remove CIP,where 95%of CIP(10 mg/L)could be degraded with the addition of 1 g/L 0.1 BSFO and 1 mmol/L PDS within 60 min.Moreover,0.1 BSFO displayed high reusability and stability with lower metal leaching.Weak acidic condition was preferred to neutral and alkaline conditions in 0.1 BSFO/PDS system.The boosted catalytic performance can be interpreted as the lower oxidation state of Fe and the existence of affluent oxygen vacancies generated by Sr doping,that induced the formation of singlet oxygen(^1O_(2))which was confirmed as the dominant reactive species by radical scavenging studies and electron spin resonance(ESR)tests.The catalytic oxidation mechanism related to major ^1O_(2) and minor free radicals was proposed.Current study opens a new avenue to develop effective A-site modified perovskite and expands their application for PDS activation in wastewater remediation.
文摘Magnetic Cuº/Fe_(3)O_(4)submicron composites were prepared using a hydrothermal method and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)and the degradation of organic pollutants.The as-prepared magnetic Cu/Fe_(3)O_(4)submicron composites were composed of Cu°and FesO+crystals and had an average size of approximately 220 nm.The Cu/FesO+composites could efficiently catalyze the activation of PMS to generate singlet oxygen,and thusinduced the rapid degradation of rhodamine B,methylene blue,orange 1l,phenol and 4-chlorophenol.The use of 0.1 g/L of the Cu°/Fe_(3)O_(4)composites induced the complete removal of rhodamine B(20μmol/L)in 15 min,methylene blue(20μmol/L)in 5 min,orange II(20μmol/L)in 10 min,phenol(0.1 mmol/L)in 30 min and 4-chlorophenol(0.1 mmol/L)in 15 min with an initial pH value of 7.0 and a PMS concentration of 0.5 mmol/L.The total organic carbon(TOC)removal higher than 85%for all of these five pollutants was obtained in 30 min when the PMS concentration was 2.5 mmol/L.The rate of degradation was considerably higher than that obtained with Cuªor FezO4 particles alone.The enhanced catalytic activity of the Cu°/Fe_(3)O_(4)composites in the activation of PMS was attributed to the synergistic effect of the Cu*and Fe_(3)O_(4)crystals in the composites.Singlet oxygen was identi-fied as the primary reactive oxygen species responsible for pollutant degradation by electron spin resonance and radical quenching experiments.A possible mechanism for the activation of PMS by Cu°/Fe_(3)O_(4)composites is proposed as electron transfer from the organic pollutants to PMS induces the activation of PMS to generate 10z,which induces the degradation of the organic pollutants.As a magnetic catalyst,the Cu°/Fe_(3)O_(4)composites were easily recovered by magnetic separation,and exhibited excellent stability over five successive degradation cycles.The present study provides a facile and green heterogeneous catalysis method for the oxidative removal of organic pollutants.
