In this study,a nickel-based MOF{(NH_(2)(CH_(3))_(2))_(2)[Ni_(3)(O)(L)3(NH(CH_(3))_(2))_(3)]}_(n)(Ni_(3)-MOF),with pore sizes of approximately 1.6 nm×1.6 nm,was synthesized by reacting 4,4′-biphenyldicarboxylic ...In this study,a nickel-based MOF{(NH_(2)(CH_(3))_(2))_(2)[Ni_(3)(O)(L)3(NH(CH_(3))_(2))_(3)]}_(n)(Ni_(3)-MOF),with pore sizes of approximately 1.6 nm×1.6 nm,was synthesized by reacting 4,4′-biphenyldicarboxylic acid(H_(2)L)with Ni(NO_(3))_(2)·6H_(2)O in an N,N-dimethylformamide(DMF)solution.The nanoscale adsorbent Ni_(3)-MOF-N with a particle diameter of approximately 200 nm was prepared using Ni_(3)-MOF.It exhibited a maximum equilibrium tetracycline(TC)adsorption capacity of 358.2 mg·g^(-1)at its isoelectric point(pH=6.50),outperforming most reported MOF-based adsorbents.This exceptional performance is likely attributed to the well-matched pore size of Ni_(3)-MOF-N(1.6 nm×1.6 nm)and the molecular dimensions of TC(0.8 nm×1.2 nm),combined with the presence of partial Ni(Ⅱ)sites on the surface of Ni_(3)-MOF-N.These features collectively facilitate effective TC adsorption through a combination of pore filling,electrostatic attraction,hydrogen bonding,surface complexation,andπ-πinteractions.Recycling experiments demonstrated that Ni_(3)-MOF-N possesses excellent structural stability and consistent adsorption performance.CCDC:2481791,Ni_(3)-MOF.展开更多
To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesize...To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesized via a combined method of thermal polymerization,hydrothermal synthesis,and calcination.The crystal structures,morphological features,and optical properties of the composites were systematically characterized,and their photocatalytic performance was evaluated through tetracycline(TC)degradation and hydrogen evolution experiments.Trapping experiments and electron paramagnetic resonance(EPR)measurements were conducted to elucidate the reaction mechanisms.The results demonstrate that the S-scheme heterojunction effectively extends the visible-light absorption range and facilitates the efficient separation of photogenerated electron-hole pairs.Under optimal conditions,the composite achieved a TC degradation rate of 94.5%and a hydrogen evolution rate of 329.1μmol·h^(-1)·g^(-1) after 8 h of irradiation,both values being significantly higher than those of pristine g-C_(3)N_(4) or TiO_(2).Moreover,the S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction retained high photocatalytic activity over five consecutive cycles,confirming its excellent stability.Mechanistic investigations revealed that the S-scheme heterojunction maintained strong redox capacities,with superoxide radicals(·O_(2)^(-)),hydroxyl radicals(·OH),electrons(e-),and holes(h+)serving as the primary active species responsible for TC degradation and H2 production.展开更多
AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(...AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS),photoluminescence(PL)spectroscopy,electron spin resonance(ESR)spectroscopy,transient photocurrent and electrochemical impedance spectroscopy(EIS)were used to characterize binary composites.Tetracycline(TC)was used as a substrate to study the performance efficiency of the degradation of photocatalysts under light conditions,and the degradation effect of TC was also evaluated under different mass concentrations and ionic contents.In addition,we further investigated the photocatalytic mechanism of the binary composite material AgVO_(3)/ZIF-8 and identified the key active components responsible for the catalytic degradation of this new photocatalyst.The experimental results show that the degradation efficiency of 10%-AZ,prepared with a molar ratio of 10%AgVO_(3)and ZIF-8 to TC,was 75.0%.This indicates that the photocatalytic activity can be maintained even under a certain ionic content,making it a suitable photocatalyst for optimal use.In addition,the photocatalytic mechanism of binary composites was further studied by the active species trapping experiment.展开更多
Natural minerals receive growing attention as inexpensive, green, and efficient catalysts for degradation of organic pollutants. Mechanical activation of natural chalcopyrite was conducted for improving the catalytic ...Natural minerals receive growing attention as inexpensive, green, and efficient catalysts for degradation of organic pollutants. Mechanical activation of natural chalcopyrite was conducted for improving the catalytic performance.Tetracycline degradation was evaluated in the presence of hydrogen peroxide and mechanically activated chalcopyrite.Tetracycline degradation at 100 min is 55.52%(Chp10), 68.97%(Chp30), 77.79%(Chp60), and 86.43%(Chp120),respectively, and the rate constant of pseudo-first-order kinetics is 0.0079, 0.0109, 0.0137 and 0.0192 min^(-1), respectively.Chalcopyrite samples were examined by multiple characterizations. Mechanical activation of natural chalcopyrite induces the decline of particle size and slight increase of surface area, smaller grain size, lattice strain, and partial sulfur oxidation. The relationship between catalytic activity and property change manifests that the improved catalytic ability is mainly ascribed to the increase of surface area and surface oxidation induced by mechanical activation. This work provides novel insights into the improvement of catalytic performance of natural minerals by mechanical activation.展开更多
The removal of the antibiotic compound tetracycline hydrochloride (TC) was investigated by using goethite/H2O2 as a heterogeneous Fenton reagent. Five principle operational parameters, especially solution pH value, we...The removal of the antibiotic compound tetracycline hydrochloride (TC) was investigated by using goethite/H2O2 as a heterogeneous Fenton reagent. Five principle operational parameters, especially solution pH value, were taken into account to investigate how the heterogeneous Fenton process factors mediated the TC removal. This process was effective but seriously impacted by the pH value and temperature, as well as the dosages of α-FeOOH, TC and H2O2. Very interestingly, the acidic and alkaline aqueous medium conditions were both very favorable due to the occurrence of transformation of Fe(III) to Fe(II) on goethite surfaces reduced by TC at pH 3.0~4.0 even though with a low adsorption capacity of TC because its maximum adsorption of negatively charged form occurred at pH around 8.0[1], thereby greatly promoting the TC Fenton oxidative elimination. However, a rapid initial TC decay was observed at the first 5 min, followed by a much slower retardation stage, which was likely because the reductive transformation of Fe(III) to Fe(II) by TC in the solution was inhibited as the Fenton reaction proceeded. Moreover, the hydroxyl radical scavenger t-butanol addition can decrease the removal rate of TC in the goethite/H2O2 system to a certain extent. This further indicated that the main reactive species in this process were hydroxyl radicals[2]. All the goethite-catalysed heterogeneous Fenton reactions are responsible for the TC removal following the Langmuir-Hinshelwood model, were well fitted to pseudo-first order kinetics (R2】0.99), and their apparent activation energy (E) for this Fenton-like reaction was 31.86 kJ mol 1, a low value that is highly consistent with the ease of TC decay greatly enhanced by the temperature rise, indicated that the interfacial controlling interactions such as a proton induced solubilization and a reductive dissolution of goethite can clearly improve its Fenton catalytic activity[3], and these dissolution processes may not be effective in some cases, while the TC adsorption process may always play an important role to control the TC removal rate during the Fenton reaction.展开更多
A novel nitrogen-doped graphene(NG)supporting magnetic nanoparticles(Fe and Fe_(3)C)was synthesized from g-C_(3)N_(4)and Fe(C_(5)H_(5))_(2).When used as a photocatalyst exposed to visible light,the material was excell...A novel nitrogen-doped graphene(NG)supporting magnetic nanoparticles(Fe and Fe_(3)C)was synthesized from g-C_(3)N_(4)and Fe(C_(5)H_(5))_(2).When used as a photocatalyst exposed to visible light,the material was excellent in degrading tetracycline(TC)in aqueous solutions.Scanning electron microscopy indicated that it had a folded sheet structure,with numerous nanoparticles observed on graphene sheets.Raman spectroscopy confirmed the presence of significant defects in the material,which suppressed the recombination of photogenerated electron-hole pairs.The performance and degradation mechanism of the photocatalyst was verified using a series of optical and electrochemical experiments and theoretical calculations.The degradation efficiency of the catalyst for TC was as high as 97.1%in 120 min under visible light irradiation,which is superior to other reported catalysts.A mechanism study showed that TC is rapidly degraded into CO_(2),H_(2)O and other small inorganic molecules,with holes(h^(+))serving as the primary driving force.The catalyst had an outstanding stability and reusability,and could be easily recovered using an external magnetic field.展开更多
Developing a low-cost stable and high-performance peroxymonosulfate(PMS)catalyst to degrade refractory organic pollutants is still an urgent problem.Herein,this study reported FeVO_(4)nanorods decorated sepiolite(FeVO...Developing a low-cost stable and high-performance peroxymonosulfate(PMS)catalyst to degrade refractory organic pollutants is still an urgent problem.Herein,this study reported FeVO_(4)nanorods decorated sepiolite(FeVO_(4)/sepiolite)through simple hydrothermal method as an adsorptive-catalyst for PMS activation to degrade tetracycline(TC).Benefiting from the introduction of sepiolite support,FeVO_(4)nanorods could be uniformly immobilized onto fibrous sepiolite surface.As a result,FeVO_(4)/sepiolite composite was endowed with excellent adsorption properties,rich surface hydroxyl groups,more reaction active sites,and the stable redox cycle of Fe^(3+)/Fe^(2+)and V5^(+)/V4^(+).Therefore,higher TC degradation efficiency(91.19%within 40 min)and larger reaction rate constant(0.1649 min^(-1))were obtained in FeVO_(4)/sepiolite/PMS system than in FeVO_(4)/PMS system.Besides,the composite presented good stability and reusability,and the effects of application parameters on TC degradation were investigated in detail.Through quenching experiment and electron paramagentic resonance(EPR)test,it was found that both radical and non-radical species participates in TC degradation,and ^(1)O_(2) were the main active species.The PMS activation mechanism was proposed,and the possible degradation pathway was also analyzed according to the high performance liquid chromatography-mass spectrometry(HPLC-MS)results.Overall,this work provides meaningful insights for designing natural mineral based PMS activators to effectively remediate antibiotic wastewater.展开更多
Herein,a luminescent europium-based metal-organic framework(Eu-MOF,[Eu_(3)(L)(HL)(NO_(3))_(2)(DMF)_(2)]·4DMF·5H_(2)O,H_(4)L=5,5′-(pyrazine-2,6-diyl)diisophthalic acid,DMF=N,N-dimethylformamide)was developed...Herein,a luminescent europium-based metal-organic framework(Eu-MOF,[Eu_(3)(L)(HL)(NO_(3))_(2)(DMF)_(2)]·4DMF·5H_(2)O,H_(4)L=5,5′-(pyrazine-2,6-diyl)diisophthalic acid,DMF=N,N-dimethylformamide)was developed for the dual-functional detection of environmental pollutants.This fluorescence-quenching-based sensor exhibited excep-tional sensitivity for both 2,4,6-trinitrophenol(TNP)and tetracycline(TC),achieving remarkably low detection lim-its of 1.96×10^(-6)and 1.71×10^(-7)mol·L^(-1),respectively.Notably,the system exhibited 99%fluorescence quenching ef-ficiency for TC,indicating ultra-efficient analyte recognition.The detection performance surpasses most reported lu-minescent MOF sensors,attributed to synergistic mechanisms of fluorescence resonance energy transfer(FRET)and photoinduced electron transfer(PET).CCDC:2446483.展开更多
A method for simultaneous analysis of five tetracyclines(tetracycline,oxytetracycline,chlortetracycline,doxycycline and minocycline) in bovine muscle was developed by UPLC-MS/MS.The sample was extracted with Mcllvaine...A method for simultaneous analysis of five tetracyclines(tetracycline,oxytetracycline,chlortetracycline,doxycycline and minocycline) in bovine muscle was developed by UPLC-MS/MS.The sample was extracted with Mcllvaine buffer-EDTA(pH 4.0) and cleaned up by solid-phase extraction on Oasis HLB cartridges.Analytes were separated by UPLC,and detected by mass spectrum with MRM mode.The calibration curves showed good linear relations in the concentration range of 1-100 μg·L-1(r>0.994) for five tetracyclines.The average recoveries at the spiked concentration levels of 1,20,50 and 100 μg·kg-1 were range of 68%-105% and the RSD were less than 34.1%.The LOD of the method was 0.05 μg·kg-1 for five tetracyclines.展开更多
A method for simultaneous determination of oxytetracycline,tetracycline,chlortetracycline in animal tissue was successfully established by HPLC-ESI MS/MS.The tetracycline antibiotics in animal tissue were extracted by...A method for simultaneous determination of oxytetracycline,tetracycline,chlortetracycline in animal tissue was successfully established by HPLC-ESI MS/MS.The tetracycline antibiotics in animal tissue were extracted by liquid-solid extraction and cleaned up by SPE.The mass spectrometer was operated in the positive-ion mode using selected reaction monitoring(SRM).The results showed that three tetracycline antibiotics were well separated under the optimal conditions.The detection limits of oxytetracycline,tetracycline and chlortetracycline were 0.16 ng/g,0.1 ng/g and 0.1 ng/g,respectively.The spiked recoveries were range of 84%-94% and the relative standard deviations were 2.4%-2.9%.展开更多
Graphitic carbon nitride(g-C_(3)N_(4))is a promising semiconductor photocatalytic material to treat residual organic pollutants due to its advantages in photoelectric properties,physical chemical stability,redox prope...Graphitic carbon nitride(g-C_(3)N_(4))is a promising semiconductor photocatalytic material to treat residual organic pollutants due to its advantages in photoelectric properties,physical chemical stability,redox properties and so on.However,the unmodified g-C_(3)N_(4)catalyst has defects such as wide band gap,small specific surface area,and low efficiency of photogenerated electron hole separation,which limited its application in the field of photocatalysis.To overcome its drawbacks,herein,we presented a facile NaOH/KOH-assited thermal condensation approach to prepare a series of element doping(Na or K)and N vacancies simultaneously functionalized carbon nitride(DCN-xNa or DCN-xK).The modified g-C_(3)N_(4)showed a significantly enhanced photocatalytic degradation tetracycline hydrochloride(TC-HCl)activity.Surprisingly,DCN-6Na and DCN-8K exhibited a high TC-HCl degradation activity of 50%(2.4 times as much as that of pristine g-C_(3)N_(4))and a high TC-HCl degradation activity of 56%(2.7 times as much as that of pristine g-C_(3)N_(4)),respectively.The related characterizations confirmed that the accompanying Na/K doping and nitrogen defect structure characteristics improved the optical absorption ability and the effective separation of photogenerated carriers.The major active species in the photocatalytic process are superoxide radicals(•O_(2)^(−))and photo-induced holes(h+).展开更多
文摘In this study,a nickel-based MOF{(NH_(2)(CH_(3))_(2))_(2)[Ni_(3)(O)(L)3(NH(CH_(3))_(2))_(3)]}_(n)(Ni_(3)-MOF),with pore sizes of approximately 1.6 nm×1.6 nm,was synthesized by reacting 4,4′-biphenyldicarboxylic acid(H_(2)L)with Ni(NO_(3))_(2)·6H_(2)O in an N,N-dimethylformamide(DMF)solution.The nanoscale adsorbent Ni_(3)-MOF-N with a particle diameter of approximately 200 nm was prepared using Ni_(3)-MOF.It exhibited a maximum equilibrium tetracycline(TC)adsorption capacity of 358.2 mg·g^(-1)at its isoelectric point(pH=6.50),outperforming most reported MOF-based adsorbents.This exceptional performance is likely attributed to the well-matched pore size of Ni_(3)-MOF-N(1.6 nm×1.6 nm)and the molecular dimensions of TC(0.8 nm×1.2 nm),combined with the presence of partial Ni(Ⅱ)sites on the surface of Ni_(3)-MOF-N.These features collectively facilitate effective TC adsorption through a combination of pore filling,electrostatic attraction,hydrogen bonding,surface complexation,andπ-πinteractions.Recycling experiments demonstrated that Ni_(3)-MOF-N possesses excellent structural stability and consistent adsorption performance.CCDC:2481791,Ni_(3)-MOF.
文摘To overcome the limitations of traditional photocatalysts,such as inefficient separation of charge carriers and poor visible-light absorption,S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction photocatalysts were synthesized via a combined method of thermal polymerization,hydrothermal synthesis,and calcination.The crystal structures,morphological features,and optical properties of the composites were systematically characterized,and their photocatalytic performance was evaluated through tetracycline(TC)degradation and hydrogen evolution experiments.Trapping experiments and electron paramagnetic resonance(EPR)measurements were conducted to elucidate the reaction mechanisms.The results demonstrate that the S-scheme heterojunction effectively extends the visible-light absorption range and facilitates the efficient separation of photogenerated electron-hole pairs.Under optimal conditions,the composite achieved a TC degradation rate of 94.5%and a hydrogen evolution rate of 329.1μmol·h^(-1)·g^(-1) after 8 h of irradiation,both values being significantly higher than those of pristine g-C_(3)N_(4) or TiO_(2).Moreover,the S-scheme g-C_(3)N_(4)/TiO_(2) heterojunction retained high photocatalytic activity over five consecutive cycles,confirming its excellent stability.Mechanistic investigations revealed that the S-scheme heterojunction maintained strong redox capacities,with superoxide radicals(·O_(2)^(-)),hydroxyl radicals(·OH),electrons(e-),and holes(h+)serving as the primary active species responsible for TC degradation and H2 production.
文摘AgVO_(3)/ZIF-8 composites with enhanced photocatalytic effect were prepared by the combination of AgVO_(3)and ZIF-8.X-ray diffraction(XRD),scanning electron microscopy(SEM),high-power transmission electron microscopy(HRTEM),X-ray photoelectron spectroscopy(XPS),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS),photoluminescence(PL)spectroscopy,electron spin resonance(ESR)spectroscopy,transient photocurrent and electrochemical impedance spectroscopy(EIS)were used to characterize binary composites.Tetracycline(TC)was used as a substrate to study the performance efficiency of the degradation of photocatalysts under light conditions,and the degradation effect of TC was also evaluated under different mass concentrations and ionic contents.In addition,we further investigated the photocatalytic mechanism of the binary composite material AgVO_(3)/ZIF-8 and identified the key active components responsible for the catalytic degradation of this new photocatalyst.The experimental results show that the degradation efficiency of 10%-AZ,prepared with a molar ratio of 10%AgVO_(3)and ZIF-8 to TC,was 75.0%.This indicates that the photocatalytic activity can be maintained even under a certain ionic content,making it a suitable photocatalyst for optimal use.In addition,the photocatalytic mechanism of binary composites was further studied by the active species trapping experiment.
基金Project(2020YFC1908802) supported by the National Key Research and Development Project of China。
文摘Natural minerals receive growing attention as inexpensive, green, and efficient catalysts for degradation of organic pollutants. Mechanical activation of natural chalcopyrite was conducted for improving the catalytic performance.Tetracycline degradation was evaluated in the presence of hydrogen peroxide and mechanically activated chalcopyrite.Tetracycline degradation at 100 min is 55.52%(Chp10), 68.97%(Chp30), 77.79%(Chp60), and 86.43%(Chp120),respectively, and the rate constant of pseudo-first-order kinetics is 0.0079, 0.0109, 0.0137 and 0.0192 min^(-1), respectively.Chalcopyrite samples were examined by multiple characterizations. Mechanical activation of natural chalcopyrite induces the decline of particle size and slight increase of surface area, smaller grain size, lattice strain, and partial sulfur oxidation. The relationship between catalytic activity and property change manifests that the improved catalytic ability is mainly ascribed to the increase of surface area and surface oxidation induced by mechanical activation. This work provides novel insights into the improvement of catalytic performance of natural minerals by mechanical activation.
文摘The removal of the antibiotic compound tetracycline hydrochloride (TC) was investigated by using goethite/H2O2 as a heterogeneous Fenton reagent. Five principle operational parameters, especially solution pH value, were taken into account to investigate how the heterogeneous Fenton process factors mediated the TC removal. This process was effective but seriously impacted by the pH value and temperature, as well as the dosages of α-FeOOH, TC and H2O2. Very interestingly, the acidic and alkaline aqueous medium conditions were both very favorable due to the occurrence of transformation of Fe(III) to Fe(II) on goethite surfaces reduced by TC at pH 3.0~4.0 even though with a low adsorption capacity of TC because its maximum adsorption of negatively charged form occurred at pH around 8.0[1], thereby greatly promoting the TC Fenton oxidative elimination. However, a rapid initial TC decay was observed at the first 5 min, followed by a much slower retardation stage, which was likely because the reductive transformation of Fe(III) to Fe(II) by TC in the solution was inhibited as the Fenton reaction proceeded. Moreover, the hydroxyl radical scavenger t-butanol addition can decrease the removal rate of TC in the goethite/H2O2 system to a certain extent. This further indicated that the main reactive species in this process were hydroxyl radicals[2]. All the goethite-catalysed heterogeneous Fenton reactions are responsible for the TC removal following the Langmuir-Hinshelwood model, were well fitted to pseudo-first order kinetics (R2】0.99), and their apparent activation energy (E) for this Fenton-like reaction was 31.86 kJ mol 1, a low value that is highly consistent with the ease of TC decay greatly enhanced by the temperature rise, indicated that the interfacial controlling interactions such as a proton induced solubilization and a reductive dissolution of goethite can clearly improve its Fenton catalytic activity[3], and these dissolution processes may not be effective in some cases, while the TC adsorption process may always play an important role to control the TC removal rate during the Fenton reaction.
文摘A novel nitrogen-doped graphene(NG)supporting magnetic nanoparticles(Fe and Fe_(3)C)was synthesized from g-C_(3)N_(4)and Fe(C_(5)H_(5))_(2).When used as a photocatalyst exposed to visible light,the material was excellent in degrading tetracycline(TC)in aqueous solutions.Scanning electron microscopy indicated that it had a folded sheet structure,with numerous nanoparticles observed on graphene sheets.Raman spectroscopy confirmed the presence of significant defects in the material,which suppressed the recombination of photogenerated electron-hole pairs.The performance and degradation mechanism of the photocatalyst was verified using a series of optical and electrochemical experiments and theoretical calculations.The degradation efficiency of the catalyst for TC was as high as 97.1%in 120 min under visible light irradiation,which is superior to other reported catalysts.A mechanism study showed that TC is rapidly degraded into CO_(2),H_(2)O and other small inorganic molecules,with holes(h^(+))serving as the primary driving force.The catalyst had an outstanding stability and reusability,and could be easily recovered using an external magnetic field.
基金Project(23-2-1-107-zyyd-jch)supported by the Qingdao Natural Science Foundation,ChinaProject(ZR2022QE236)supported by the Natural Science Foundation of Shandong Province Youth Project,China+2 种基金Project(SDCX-ZG-202400211,SDCX-ZG-202203052)supported by the Shandong Postdoctoral Science Foundation,ChinaProject(ZD2023K03)supported by the Engineering Research Center of Non-metallic Minerals of Zhejiang Province,ChinaProject(01020240806)supported by the Qingdao Postdoctoral Program for Applied Research,China。
文摘Developing a low-cost stable and high-performance peroxymonosulfate(PMS)catalyst to degrade refractory organic pollutants is still an urgent problem.Herein,this study reported FeVO_(4)nanorods decorated sepiolite(FeVO_(4)/sepiolite)through simple hydrothermal method as an adsorptive-catalyst for PMS activation to degrade tetracycline(TC).Benefiting from the introduction of sepiolite support,FeVO_(4)nanorods could be uniformly immobilized onto fibrous sepiolite surface.As a result,FeVO_(4)/sepiolite composite was endowed with excellent adsorption properties,rich surface hydroxyl groups,more reaction active sites,and the stable redox cycle of Fe^(3+)/Fe^(2+)and V5^(+)/V4^(+).Therefore,higher TC degradation efficiency(91.19%within 40 min)and larger reaction rate constant(0.1649 min^(-1))were obtained in FeVO_(4)/sepiolite/PMS system than in FeVO_(4)/PMS system.Besides,the composite presented good stability and reusability,and the effects of application parameters on TC degradation were investigated in detail.Through quenching experiment and electron paramagentic resonance(EPR)test,it was found that both radical and non-radical species participates in TC degradation,and ^(1)O_(2) were the main active species.The PMS activation mechanism was proposed,and the possible degradation pathway was also analyzed according to the high performance liquid chromatography-mass spectrometry(HPLC-MS)results.Overall,this work provides meaningful insights for designing natural mineral based PMS activators to effectively remediate antibiotic wastewater.
文摘Herein,a luminescent europium-based metal-organic framework(Eu-MOF,[Eu_(3)(L)(HL)(NO_(3))_(2)(DMF)_(2)]·4DMF·5H_(2)O,H_(4)L=5,5′-(pyrazine-2,6-diyl)diisophthalic acid,DMF=N,N-dimethylformamide)was developed for the dual-functional detection of environmental pollutants.This fluorescence-quenching-based sensor exhibited excep-tional sensitivity for both 2,4,6-trinitrophenol(TNP)and tetracycline(TC),achieving remarkably low detection lim-its of 1.96×10^(-6)and 1.71×10^(-7)mol·L^(-1),respectively.Notably,the system exhibited 99%fluorescence quenching ef-ficiency for TC,indicating ultra-efficient analyte recognition.The detection performance surpasses most reported lu-minescent MOF sensors,attributed to synergistic mechanisms of fluorescence resonance energy transfer(FRET)and photoinduced electron transfer(PET).CCDC:2446483.
文摘A method for simultaneous analysis of five tetracyclines(tetracycline,oxytetracycline,chlortetracycline,doxycycline and minocycline) in bovine muscle was developed by UPLC-MS/MS.The sample was extracted with Mcllvaine buffer-EDTA(pH 4.0) and cleaned up by solid-phase extraction on Oasis HLB cartridges.Analytes were separated by UPLC,and detected by mass spectrum with MRM mode.The calibration curves showed good linear relations in the concentration range of 1-100 μg·L-1(r>0.994) for five tetracyclines.The average recoveries at the spiked concentration levels of 1,20,50 and 100 μg·kg-1 were range of 68%-105% and the RSD were less than 34.1%.The LOD of the method was 0.05 μg·kg-1 for five tetracyclines.
文摘A method for simultaneous determination of oxytetracycline,tetracycline,chlortetracycline in animal tissue was successfully established by HPLC-ESI MS/MS.The tetracycline antibiotics in animal tissue were extracted by liquid-solid extraction and cleaned up by SPE.The mass spectrometer was operated in the positive-ion mode using selected reaction monitoring(SRM).The results showed that three tetracycline antibiotics were well separated under the optimal conditions.The detection limits of oxytetracycline,tetracycline and chlortetracycline were 0.16 ng/g,0.1 ng/g and 0.1 ng/g,respectively.The spiked recoveries were range of 84%-94% and the relative standard deviations were 2.4%-2.9%.
基金The National Natural Science Foundation of China(22361001)The Natural Science Foundation of Inner Mongolia,China(2023LHMS02010)Entrepreneurship Training Program of Inner Mongolia Autonomous Region,China(S202310138022).
文摘Graphitic carbon nitride(g-C_(3)N_(4))is a promising semiconductor photocatalytic material to treat residual organic pollutants due to its advantages in photoelectric properties,physical chemical stability,redox properties and so on.However,the unmodified g-C_(3)N_(4)catalyst has defects such as wide band gap,small specific surface area,and low efficiency of photogenerated electron hole separation,which limited its application in the field of photocatalysis.To overcome its drawbacks,herein,we presented a facile NaOH/KOH-assited thermal condensation approach to prepare a series of element doping(Na or K)and N vacancies simultaneously functionalized carbon nitride(DCN-xNa or DCN-xK).The modified g-C_(3)N_(4)showed a significantly enhanced photocatalytic degradation tetracycline hydrochloride(TC-HCl)activity.Surprisingly,DCN-6Na and DCN-8K exhibited a high TC-HCl degradation activity of 50%(2.4 times as much as that of pristine g-C_(3)N_(4))and a high TC-HCl degradation activity of 56%(2.7 times as much as that of pristine g-C_(3)N_(4)),respectively.The related characterizations confirmed that the accompanying Na/K doping and nitrogen defect structure characteristics improved the optical absorption ability and the effective separation of photogenerated carriers.The major active species in the photocatalytic process are superoxide radicals(•O_(2)^(−))and photo-induced holes(h+).
