Two-dimensional black phosphorus(2D BP)utilized in flame retardant applications frequently encounters significant challenges,including inadequate ambient stability and elevated carbon monoxide(CO)release rates.To miti...Two-dimensional black phosphorus(2D BP)utilized in flame retardant applications frequently encounters significant challenges,including inadequate ambient stability and elevated carbon monoxide(CO)release rates.To mitigate these issues,an effective approach was proposed for the fabrication of 2D heterostructures comprising copper oxide intercalated with BP in this work.This methodology takes into account both thermodynamic and kinetic factors,resulting in substantial enhancements in the ambient stability of BP and the catalytic performance for CO elimination,achieved through the synergistic interactions between 2D BP and copper oxide,all while preserving the structural integrity of 2D BP.The incorporation of gelatin and kosmotropic anions facilitated the efficient adhesion of the multifunctional heterostructures to the flammable flexible polyurethane foam(FPUF),which not only scavenged free radicals in the gas phase but also catalyzed the formation of a dense carbon layer in the condensed phase.Kosmotropic anions induce a salting-out effect that fosters the development of a chain bundle,a hydrophobic interaction domain,and a potential microphase separation region within the gelatin chains,leading to a marked improvement in the mechanical strength of the heterostructure coatings.The modified FPUF exhibited a high limiting oxygen index(LOI)value of 34%,alongside significantly improved flame resistance:the peak CO release rate was reduced by 78%,the peak heat release rate decreased by 57%,and the fire performance index(FPI)was increased by 40 times compared to untreated FPUF.The 2D heterostructure coatings demonstrated better CO catalytic removal performance relative to previously reported flame retardant products.This research offers a promising design principle for the development of next-generation high-performance flame retardant coatings aimed at enhancing fire protection.展开更多
The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most po...The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most popular method for overcoming the above inadequacies.In this work,a CdZnS/TiO_(2) membrane photocatalyst with adjustable suspended depth(include floating)and flexible assembly is designed,which is less prone to dislodgement due to in situ synthesis and has a wider range of applicability than previously reported photocatalysts.The photocatalytic removal of Microcystis aeruginosa revealed that the suspended depth and distribution format of the CdZnS/TiO_(2) membrane photocatalysts have striking effects on the photocatalytic removal performance of Microcystis aeruginosa,the photocatalytic removal efficiency of CdZnS/TiO_(2)-2 membrane photocatalysts for Microcystis aeruginosa could reach to 98.6%in 60 min when the photocatalysts assembled in the form of 3×3 arrays suspended at a depth of 2 cm from the liquid surface.A tiny amount of TiO_(2) loading allows the formation of Z-Scheme heterojunction,resulting in accelerating the separation efficiency of photogenerated carriers,preserving the photogenerated electrons and holes with stronger reduction and oxidation ability and inhabiting the photo-corrosion of CdZnS.展开更多
Carbon-based materials have been widely applied for pollutant removal relying on their rich pore structure,functional groups,chemical stability,and expandability.However,the traditional manufacturing process of carbon...Carbon-based materials have been widely applied for pollutant removal relying on their rich pore structure,functional groups,chemical stability,and expandability.However,the traditional manufacturing process of carbon materials based on organic compounds pyrolysis is high energy-consuming and high-emission,which is not conducive to addressing the climate crisis and achieving the goal of carbon neutrality.Molten salt electrolysis technology enables the direct capture and reduction of CO_(2)to produce solid carbon,resulting in significant environmental benefits while achieving carbon emissions reduction.The molten salt also has a purification function,enabling the production of high-purity carbon materials.The kinetics of the electrochemical reduction process can be easily controlled,and the co-reduction of multiple elements provides convenience for the in-situ optimization of carbon material structure and the expansion of its applications.Therefore,this review focuses on the thermodynamics&kinetics processes of molten salt capture and electrochemical reduction of CO_(2)to prepare carbon materials.It further reviews the recent research progress on the preparation of carbon materials for pollutant removal based on molten salt electrochemical processes for the first time.Finally,we analyze the advantages and challenges of the current molten salt electrochemical processes and offers prospects for future research directions.展开更多
Removal of SO2 and NOx by pulsed corona combined with in situ alkali absorption was experimentally investigated.In the reactor,a plate-wire-plate combination is devised for generating pulsed corona and then alkaline a...Removal of SO2 and NOx by pulsed corona combined with in situ alkali absorption was experimentally investigated.In the reactor,a plate-wire-plate combination is devised for generating pulsed corona and then alkaline absorbent slurries were introduced into the reactor by a continuous band conveying system to capture the gaseous reaction products.It was found that both SO2 and NO could be removed by corona combined with in situ alkali absorption.The removal of SO2 increased to 75%with the corona discharge,compared with 60%removal only with Ca(OH)2 absorption.About 40%removal of NO was reached by pulsed corona combined with in situ Ca(OH)2 absorption.It was found that SO2 and NO in the gas stream are oxidized to SO3 and NO2 by pulsed corona respectively,and then absorbed by the alkali in the reactor.The removals of SO2 as well as NO were higher with Ca(OH)2 as the absorbent,compared with using CaCO3 or ZnO.展开更多
In order to investigate the feasibility of sequential removal NO and SO2 using non-thermal plasma and adsorbent simultaneously, the removal of NO and SO2 from dry gas stream （NO/SO2/N2/O2） with very little O2 using ...In order to investigate the feasibility of sequential removal NO and SO2 using non-thermal plasma and adsorbent simultaneously, the removal of NO and SO2 from dry gas stream （NO/SO2/N2/O2） with very little O2 using non-thermal plasma was investigated using a coaxial dielectric barrier discharge. Comparative experiments were carried out in the dry gas stream with and without Ar respectively at O2 concentration of 0.1%. The results showed that NO could be removed remarkably and it would be enhanced in the presence of Ar in the dry gas stream. It seems that SO2 could not be removed unless there is Ar in the dry gas stream. The mechanism of removal of NO and SO2 in the dry gas stream was discussed.展开更多
The application of photocatalytic technology in treating various environmental pollution issues has been extensively studied.However,its further utilization has been hindered by the limited response to visible light a...The application of photocatalytic technology in treating various environmental pollution issues has been extensively studied.However,its further utilization has been hindered by the limited response to visible light and the serious recombination of charge carriers.In this study,the two-dimensional(2D)layered carbon-supported TiO_(2)particles derived from Ti_(3)C_(2)Mxene were tightly attached on Bi_(2)WO_(6)containing oxygen-rich vacancies,fabricating an efficient S-scheme bifunctional heterojunction.This development aimed to improve the photocatalytic performance towards antibiotics degradation and NO removal.The photochemical characterizations confirmed that the presence of oxygen vacancies broaden the visible light responsiveness of Bi_(2)WO_(6).Subsequently,the formation of S-scheme heterojunction between oxygen vacancy-containing Bi_(2)WO_(6)and TiO_(2)allowed for the maximum retention of the high oxidation and reduction capabilities of the monomer material.Simultaneously,layered carbon between Bi_(2)WO_(6)and TiO_(2)accelerated charge transfer and carrier separation.The optimized BWO/TiO_(2)@C exhibited superior performance,with an 84.03%degradation rate of tetracycline(TC)and a 44.2%removal rate of NO under visible light,representing 1.54 and 4.79 times the performance of the original Bi_(2)WO_(6),respectively.Intermediate species generated during the photocatalytic oxidation processes of TC and NO were identified using liquid chromatograph mass spectrometry(LC-MS)and in-situ DRIFTS.By combining electron paramagnetic resonance(EPR)and density functional theory(DFT)calculations,in-depth mechanisms were elucidated.This study sheds new light on the applications of Bi_(2)WO_(6)and MXene in photocatalysis,offering potential for the development of efficient dual-functional photocatalysts for addressing water and air pollution.展开更多
The removal and recovery of low-concentration phosphates from water have become crucial due to the dual challenges of eutrophication and the phosphorus crisis.Herein,we engineered a highly efficient and recyclable pho...The removal and recovery of low-concentration phosphates from water have become crucial due to the dual challenges of eutrophication and the phosphorus crisis.Herein,we engineered a highly efficient and recyclable phosphate trapping agent of La_(2-x)CexO_(2)CO_(3) solid solution.The incorporation of Ce enhances the surface area and surface potential of La_(2-x)CexO_(2)CO_(3),providing abundant adsorption sites for phosphate.Surprisingly,we found that adjusting the Ce proportion affects the carbonate content,thereby influencing the anion-exchange capacity between carbonate and phosphate.Specifically,at 3% Ce content(3%-CeL),the carbonate ratio is maximized,resulting in an optimal sorption capacity(196.4mg P/g)and a rapid removal rate(under 40min)for phosphate,unaffected by interfering ions.Remarkably,3%-CeL achieved nearly 100%phosphate removal efficiency in diverse water samples from sewage treatment plants,rivers,reservoirs,and groundwater.After five adsorption-desorption cycles,the phosphate removal and recovery efficiency of 3%-CeL remained above 90%.Mechanistic studies revealed that 3%Ce content yielded the highest proportion of Ce^(4+)/Ce^(3+),enabling greater carbonate binding for anion-exchange.This study proposes a high-performance phosphate trapping agentwith broad applicability for treating actual waters and provides a new perspective on enhancing low-concentration phosphate removal in La-based materials through manipulating Ce ratio and valence.展开更多
The Amazon basin plays a crucial role in biodiversity and carbon storage,but its local rainfall is anticipated to decrease under globalwarming.Carbon dioxide removal(CDR)is being considered as a method to mitigate the...The Amazon basin plays a crucial role in biodiversity and carbon storage,but its local rainfall is anticipated to decrease under globalwarming.Carbon dioxide removal(CDR)is being considered as a method to mitigate the impact of global warming.However,the specific effects of CDR on Amazon rainfall have not been well understood.Here,an idealized CDR experiment reveals that the reduced rainfall over the Amazon basin does not recover.Significantly weaker rainfall is found during the ramp-down period compared to the ramp-up period at the same CO_(2)concentration.This response is associated with the enhanced El Niño-like warming in the tropical Pacific Ocean during the CDR period.This warming pattern has dual effects:weakening the zonal circulation and causing anomalous descent directly over the Amazon basin,while also triggering a stationary Rossby wave train that propagated downstream and generated anomalous ascent over the Sargasso Sea.This anomalous ascent induces anomalous descent and weakens moisture transport over the Amazon basin by the local meridional circulation.Consequently,precipitation is reduced over the Amazon basin in response to the weakened zonal and meridional circulation.Our findings indicate that even if the atmospheric CO_(2)concentration is lowered,the Amazon basin will remain susceptible to drought.Effective local climate adaptation strategies are urgently needed to address the vulnerability of this critical ecosystem.展开更多
To study the mechanism of SO2 and Hg removal from flue gas, an experimental packed bed reactor was designed to simulate the dry FGD, where a mixture of lime and fly ash in ratio 1：3 w/w was used as the S02 and Hg sor...To study the mechanism of SO2 and Hg removal from flue gas, an experimental packed bed reactor was designed to simulate the dry FGD, where a mixture of lime and fly ash in ratio 1：3 w/w was used as the S02 and Hg sorbent, and steam at temperature of 100 ℃ was applied for activation of the sorbent, while the activation time set to 20 rain. The experimental factors including the SO2/Hg sorbent characteristics, 50% breakthrough time for SO2/Hg removal, sorbent packed bed depth and reaction temperature were investigated. The experimental results show that after steam activation, the BET specific surface area and specific pore volume increased from 37.8 to 45.5 m^2/g and from 0.42 to 0.51 cm^3/g, respectively. With activation of the sorbent by steam, the 50% breakthrough times of SO2 and Hg removal increased from 34 to 42 rain and from 23 to 45 rain, respectively. When the packed bed depth was increased from 5 to 25 ram. the 50% breakthrough times for Hg and S02 removal increased from 12 to 52 rain and from 6 to 47 rain, respectively. With the increase of the reaction temperature, the 50% breakthrough of SO2/Hg removal decreased accordingly. Steam activation can efficiently improve SO2/Hg removal simultaneously.展开更多
To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL...To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL-101 magnetic composite material was successfully synthesized via the one-pot method.Preparation conditions were optimized and structural characterization of this material conducted using FTIR,SEM,EDS,XRD and Hysteresis analysis.The results show that this composite exhibits a more rapid fluoride adsorption dynamics and a higher fluoride adsorption capacity(18.34 mg/g)and its adsorption behavior fitted for the first order dynamic model and the Freundlich isotherm model.The adsorption of fluorine by this composite is mainly physical adsorption according to the mean adsorption energy(1.216 kJ/mol).The interfering ions co-existed in fluoride-containing solutions,like HCO_(3)^(-),NO^(-)and Cl^(-),have a significant effect on fluorine adsorption.This composite has also been proved with magnetism,higher adsorption selectivity and satisfactory reusability.When this composite is employed as an adsorbent for adsorption removing fluoride in zinc sulfate electrolyte,it exhibits higher pH-dependent behavior as well as high fluoride removal efficiency at pH 6.5.展开更多
In this study, titanium dioxide supported by multi-walled carbon nano tubes(MWCNTs/TiO_2) and Cr-doped TiO_2 supported by MWCNTs(MWNTs/Cr-TiO_2) were synthesized by the sol-gel method. The prepared samples were charac...In this study, titanium dioxide supported by multi-walled carbon nano tubes(MWCNTs/TiO_2) and Cr-doped TiO_2 supported by MWCNTs(MWNTs/Cr-TiO_2) were synthesized by the sol-gel method. The prepared samples were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, the BrunauerEmmett-Teller analysis, and the Raman spectroscopy. The oxidation and efficiency for removal of SO_2 in a simulated flue gas were investigated experimentally in a fixed-bed reactor. The 15% MWCNTs/Cr-Ti02 sample displayed excellent adsorption properties, and a SO_2 removal rate equating to 30.415 1 mg/g from the simulated flue gas containing 2 300 μg/g of SO_2, 8% of 02, and 5% of H20 was achieved under optimal conditions covering a temperature of 333.15 K, and a space velocity of 1 275 h^(-1). The adsorption process was enhanced because Cr doping modified the pore structure and inhibited the grain growth of TiO_2. In addition, the Freundlich and Langmuir models revealed that SO_2 was mainly adsorbed through chemical adsorption on the sample surfaces, and the thermodynamic model analysis indicated that the adsorption was a spontaneous, exothermic, and entropy-reducing process. The adsorption kinetics of SO_2 can be described by the pseudosecond-order kinetic and the Bangham dynamics models. The possible reaction mechanism involved in desulfurization process was also proposed.展开更多
The dielectric barrier corona discharge(DBCD) in a wire-cylinder configuration and the dielectric barrier discharge(DBD) in a coaxial cylinder configuration are studied. The discharge current in DBD has a higher pulse...The dielectric barrier corona discharge(DBCD) in a wire-cylinder configuration and the dielectric barrier discharge(DBD) in a coaxial cylinder configuration are studied. The discharge current in DBD has a higher pulse amplitude than in DBCD. The dissipated power and the gas-gap voltage are calculated by analyzing the measured Lissajous figure. With the increasing applied voltage, the energy utilization factor for SO2 removal increases in DBCD but decreases in DBD because of the difference in their electric field distribution. Experiments of SO2 removal show that in the absence of NH3 the energy utilization factor can reach 31 g/kWh in DBCD and 39 g/kWh in DBD.展开更多
The industrial implementation of Solar-driven photocatalysis is hampered by inefficient charge separation,poor reusability and hard retrieval of powdery catalysts.To conquer these drawbacks,a self-floating S-scheme Bi...The industrial implementation of Solar-driven photocatalysis is hampered by inefficient charge separation,poor reusability and hard retrieval of powdery catalysts.To conquer these drawbacks,a self-floating S-scheme Bi_(4)O_(5)Br_(2)/P-doped C_(3)N_(4)/carbon fiber cloth(BB/PN/CC)composed of carbon fibers(CC)as the core and Bi_(4)O_(5)Br_(2)/P-doped C_(3)N_(4)(BB/PN)nanosheets as the shell was constructed as a competent,recyclable cloth-shaped photocatalyst for safe and efficient degradation of aquacultural antibiotics.The BB/PN/CC fabric achieves an exceptional tetracycline degradation rate constant of 0.0118 min‒1,surpassing CN/CC(0.0015 min^(‒1)),BB/CC(0.0066 min^(‒1))and PN/CC(0.0023 min^(‒1))by 6.9,0.8 and 4.1 folds,respectively.Beyond its catalytic prowess,the photocatalyst’s practical superiority is evident in its effortless recovery and environmental adaptability.The superior catalytic effectiveness stems from the S-scheme configuration,which retains the maximum redox capacities of the constituent BB and PN while enabling efficient spatial detachment of photo-carriers.X-ray photoelectron spectroscopy(XPS),in-situ XPS,and electron paramagnetic resonance analyses corroborate the S-scheme mechanism,revealing electron accumulation on PN and hole retention on BB under illumination.Density functional theory calculations further confirm S-scheme interfacial charge redistribution and internal electric field formation.This study advances the design of macroscopic S-scheme heterojunction photocatalysts for sustainable water purification.展开更多
In this paper, an experimental study on SO2 removal by nanosecond rising edge pulse dielectric barrier discharge （DBD） plasma, generated by multi-needle-to-plane electrodes, is carried out. The mechanism of the effe...In this paper, an experimental study on SO2 removal by nanosecond rising edge pulse dielectric barrier discharge （DBD） plasma, generated by multi-needle-to-plane electrodes, is carried out. The mechanism of the effect of various factors, such as gap size between dielectric barrier and discharge needles, environmental humidity, and inlet speed of gas flow upon the removal efficiency of air purification is analyzed. The studies show that SOs removal efficiency improves with the increase in the gap size between dielectric barrier and discharge needles in the case of a fixed space between two electrodes, and also improves with the increase in the environmental humidity. For a mixed gas with a fixed concentration, there is an optimal inlet speed of gas flow, which leads to the best removal efficiency.展开更多
Dielectric barrier discharge （DBD） for SOs removal from indoor air is investigated. In order to improve the removal efficiency, two novel methods are combined in this paper, namely by applying a pulsed driving volta...Dielectric barrier discharge （DBD） for SOs removal from indoor air is investigated. In order to improve the removal efficiency, two novel methods are combined in this paper, namely by applying a pulsed driving voltage with nanosecond rising time and applying a magnetic field. For SOs removal efficiency, different matches of electric field and magnetic field are discussed. And nanosecond rising edge pulsed power supply and microsecond rising edge pulsed power supply are compared. It can be concluded that a pulsed DBD with nanosecond rising edge should be adopted, and electrical field and magnetic field should be applied in an appropriate match.展开更多
In this study, lime-hydrate （Ca（OH）2） desulfurizer was treated by plasma with strong ionization discharge of a dielectric barrier. The removal of SO2 from simulated flue gas was investigated. The principles of SO2...In this study, lime-hydrate （Ca（OH）2） desulfurizer was treated by plasma with strong ionization discharge of a dielectric barrier. The removal of SO2 from simulated flue gas was investigated. The principles of SO2 removal are discussed. Several factors affecting the efficiency of SO2 removal were studied. They included the ratio of calcium to sulfur （Ca/S）, desulfurizer granularity, residence time of the flue gas, voltage applied to the discharge electrode in the plasma generator, and energy consumption. Experimental results indicate that the increase in Ca/S ratio, the applied voltage and discharge power, the residence time, and the reduction in the desulfurizer granularity all can raise the SO2 removal efficiency. The SO2 removal efficiency was up to 91.3% under the following conditions, namely a primary concentration of SO2 of 2262×10^-6 （v/v） in the emission gas, 21%（v/v） of oxygen, 1.8% （v/v） of water, a Ca/S ratio of 1.48, a residence time of 2.8 s, a 3.4 kV voltage and a 10kHz frequency power applied to the discharge electrodes in the plasma generator, and a flow rate of 100 m^3/h for emission gas.展开更多
Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of...Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of approximately 41-148 nm and are dispersed with non-uniform pores on the template surface.By swapping the salt template with KC1 or Na2SO4,different morphologies of Bi2WO6 are obtained.The experimental results demonstrate that NaCl plays a key role on the formation of Bi2WO6 with hollow structures.The specific growth mechanism of hollow microspheres was studied in detail.The Bi2WO6 hollow microspheres exhibit an excellent photocatalytic efficiency for NO removal under solar light irradiation,which is 1.73 times higher than for the Bi2WO6 obtained in the absence of any salt template.This enhancement can be ascribed to the simultaneous improvement on the surface area and visible light-harvesting ability from the hollow structures.Electron spin resonance（ESR） results suggest that both radicals of ·OH and ·O2^- are involved in the photocatalytic process over the BWO-NaCl sample.The production of ·O2^- radicals offers better durability for NO removal.展开更多
基金supported by the National Natural Science Foundation of China(52404258)Postdoctoral Fellowship Program of CPSF(GZB20230714)+1 种基金Anhui Provincial Natural Science Foundation(2408085QE173)China Postdoctoral Science Foundation funded project(2023M743387)。
文摘Two-dimensional black phosphorus(2D BP)utilized in flame retardant applications frequently encounters significant challenges,including inadequate ambient stability and elevated carbon monoxide(CO)release rates.To mitigate these issues,an effective approach was proposed for the fabrication of 2D heterostructures comprising copper oxide intercalated with BP in this work.This methodology takes into account both thermodynamic and kinetic factors,resulting in substantial enhancements in the ambient stability of BP and the catalytic performance for CO elimination,achieved through the synergistic interactions between 2D BP and copper oxide,all while preserving the structural integrity of 2D BP.The incorporation of gelatin and kosmotropic anions facilitated the efficient adhesion of the multifunctional heterostructures to the flammable flexible polyurethane foam(FPUF),which not only scavenged free radicals in the gas phase but also catalyzed the formation of a dense carbon layer in the condensed phase.Kosmotropic anions induce a salting-out effect that fosters the development of a chain bundle,a hydrophobic interaction domain,and a potential microphase separation region within the gelatin chains,leading to a marked improvement in the mechanical strength of the heterostructure coatings.The modified FPUF exhibited a high limiting oxygen index(LOI)value of 34%,alongside significantly improved flame resistance:the peak CO release rate was reduced by 78%,the peak heat release rate decreased by 57%,and the fire performance index(FPI)was increased by 40 times compared to untreated FPUF.The 2D heterostructure coatings demonstrated better CO catalytic removal performance relative to previously reported flame retardant products.This research offers a promising design principle for the development of next-generation high-performance flame retardant coatings aimed at enhancing fire protection.
基金financially supported by the Natural Science Foundation of ShanDong(Nos.ZR2023QD152 and ZR2021MD002).
文摘The application of photocatalytic technology in algae killing is limited by the non-floatability and difficulty in recycling of the photocatalysts.Loading photocatalyst on magnetic or floatable carriers is the most popular method for overcoming the above inadequacies.In this work,a CdZnS/TiO_(2) membrane photocatalyst with adjustable suspended depth(include floating)and flexible assembly is designed,which is less prone to dislodgement due to in situ synthesis and has a wider range of applicability than previously reported photocatalysts.The photocatalytic removal of Microcystis aeruginosa revealed that the suspended depth and distribution format of the CdZnS/TiO_(2) membrane photocatalysts have striking effects on the photocatalytic removal performance of Microcystis aeruginosa,the photocatalytic removal efficiency of CdZnS/TiO_(2)-2 membrane photocatalysts for Microcystis aeruginosa could reach to 98.6%in 60 min when the photocatalysts assembled in the form of 3×3 arrays suspended at a depth of 2 cm from the liquid surface.A tiny amount of TiO_(2) loading allows the formation of Z-Scheme heterojunction,resulting in accelerating the separation efficiency of photogenerated carriers,preserving the photogenerated electrons and holes with stronger reduction and oxidation ability and inhabiting the photo-corrosion of CdZnS.
基金supported by the National Natural Science Foundation of China(Nos.52200143,51979011 and 52276208)the Natural Science Foundation of Hubei Province(No.2024AFB546)the Fundamental Research Funds for Central Public Welfare Research Institutes(Nos.CKSF2023302/CL and CKSF2023314/CL).
文摘Carbon-based materials have been widely applied for pollutant removal relying on their rich pore structure,functional groups,chemical stability,and expandability.However,the traditional manufacturing process of carbon materials based on organic compounds pyrolysis is high energy-consuming and high-emission,which is not conducive to addressing the climate crisis and achieving the goal of carbon neutrality.Molten salt electrolysis technology enables the direct capture and reduction of CO_(2)to produce solid carbon,resulting in significant environmental benefits while achieving carbon emissions reduction.The molten salt also has a purification function,enabling the production of high-purity carbon materials.The kinetics of the electrochemical reduction process can be easily controlled,and the co-reduction of multiple elements provides convenience for the in-situ optimization of carbon material structure and the expansion of its applications.Therefore,this review focuses on the thermodynamics&kinetics processes of molten salt capture and electrochemical reduction of CO_(2)to prepare carbon materials.It further reviews the recent research progress on the preparation of carbon materials for pollutant removal based on molten salt electrochemical processes for the first time.Finally,we analyze the advantages and challenges of the current molten salt electrochemical processes and offers prospects for future research directions.
基金Supported by the Science and Technology Development Project of Zhejiang Province(2007C13085)Hangzhou City(20070733B28)
文摘Removal of SO2 and NOx by pulsed corona combined with in situ alkali absorption was experimentally investigated.In the reactor,a plate-wire-plate combination is devised for generating pulsed corona and then alkaline absorbent slurries were introduced into the reactor by a continuous band conveying system to capture the gaseous reaction products.It was found that both SO2 and NO could be removed by corona combined with in situ alkali absorption.The removal of SO2 increased to 75%with the corona discharge,compared with 60%removal only with Ca(OH)2 absorption.About 40%removal of NO was reached by pulsed corona combined with in situ Ca(OH)2 absorption.It was found that SO2 and NO in the gas stream are oxidized to SO3 and NO2 by pulsed corona respectively,and then absorbed by the alkali in the reactor.The removals of SO2 as well as NO were higher with Ca(OH)2 as the absorbent,compared with using CaCO3 or ZnO.
基金Project supported by the National Natural Sciences Foundation of China(No.50576037)Natural Science Foundation of Jiangsu Province(No.BK2006198)
文摘In order to investigate the feasibility of sequential removal NO and SO2 using non-thermal plasma and adsorbent simultaneously, the removal of NO and SO2 from dry gas stream （NO/SO2/N2/O2） with very little O2 using non-thermal plasma was investigated using a coaxial dielectric barrier discharge. Comparative experiments were carried out in the dry gas stream with and without Ar respectively at O2 concentration of 0.1%. The results showed that NO could be removed remarkably and it would be enhanced in the presence of Ar in the dry gas stream. It seems that SO2 could not be removed unless there is Ar in the dry gas stream. The mechanism of removal of NO and SO2 in the dry gas stream was discussed.
基金supported by the National Natural Science Foundation of China(Nos.22001026 and 52100179)the Natural Scienceof Chongqing(Nos.CSTB2024NSCQLZX0073 and CSTB2022NSCQ-MSX1308)+1 种基金the Chongqing College Students’Innovation and Entrepreneurship Training Program(No.S202311799025)the Science and Technology Research Program of Chongqing Municipal Education Commission(Nos.KJZD-K202300806,KJQN202200821,KJQN202400810,and KJQN202100831)。
文摘The application of photocatalytic technology in treating various environmental pollution issues has been extensively studied.However,its further utilization has been hindered by the limited response to visible light and the serious recombination of charge carriers.In this study,the two-dimensional(2D)layered carbon-supported TiO_(2)particles derived from Ti_(3)C_(2)Mxene were tightly attached on Bi_(2)WO_(6)containing oxygen-rich vacancies,fabricating an efficient S-scheme bifunctional heterojunction.This development aimed to improve the photocatalytic performance towards antibiotics degradation and NO removal.The photochemical characterizations confirmed that the presence of oxygen vacancies broaden the visible light responsiveness of Bi_(2)WO_(6).Subsequently,the formation of S-scheme heterojunction between oxygen vacancy-containing Bi_(2)WO_(6)and TiO_(2)allowed for the maximum retention of the high oxidation and reduction capabilities of the monomer material.Simultaneously,layered carbon between Bi_(2)WO_(6)and TiO_(2)accelerated charge transfer and carrier separation.The optimized BWO/TiO_(2)@C exhibited superior performance,with an 84.03%degradation rate of tetracycline(TC)and a 44.2%removal rate of NO under visible light,representing 1.54 and 4.79 times the performance of the original Bi_(2)WO_(6),respectively.Intermediate species generated during the photocatalytic oxidation processes of TC and NO were identified using liquid chromatograph mass spectrometry(LC-MS)and in-situ DRIFTS.By combining electron paramagnetic resonance(EPR)and density functional theory(DFT)calculations,in-depth mechanisms were elucidated.This study sheds new light on the applications of Bi_(2)WO_(6)and MXene in photocatalysis,offering potential for the development of efficient dual-functional photocatalysts for addressing water and air pollution.
基金supported by the National Key Research and Development Program of China(Nos.2022YFC3703700,2021YFA0910300,and 2021YFC3200902)the National Natural Science Foundation of China(No.22125606)+1 种基金the Special Project of Ecological Environmental Technology for Carbon Dioxide Emissions Peak and Carbon Neutrality(No.RCEESTDZ-2021-21)China South-to-North Water Diversion Corporation Limited Research Project(No.NSBDZX/SH/KY/2022-001).
文摘The removal and recovery of low-concentration phosphates from water have become crucial due to the dual challenges of eutrophication and the phosphorus crisis.Herein,we engineered a highly efficient and recyclable phosphate trapping agent of La_(2-x)CexO_(2)CO_(3) solid solution.The incorporation of Ce enhances the surface area and surface potential of La_(2-x)CexO_(2)CO_(3),providing abundant adsorption sites for phosphate.Surprisingly,we found that adjusting the Ce proportion affects the carbonate content,thereby influencing the anion-exchange capacity between carbonate and phosphate.Specifically,at 3% Ce content(3%-CeL),the carbonate ratio is maximized,resulting in an optimal sorption capacity(196.4mg P/g)and a rapid removal rate(under 40min)for phosphate,unaffected by interfering ions.Remarkably,3%-CeL achieved nearly 100%phosphate removal efficiency in diverse water samples from sewage treatment plants,rivers,reservoirs,and groundwater.After five adsorption-desorption cycles,the phosphate removal and recovery efficiency of 3%-CeL remained above 90%.Mechanistic studies revealed that 3%Ce content yielded the highest proportion of Ce^(4+)/Ce^(3+),enabling greater carbonate binding for anion-exchange.This study proposes a high-performance phosphate trapping agentwith broad applicability for treating actual waters and provides a new perspective on enhancing low-concentration phosphate removal in La-based materials through manipulating Ce ratio and valence.
基金supported by the National Natural Science Foundation of China(Nos.42141019,42175055,and 42261144687)the second Tibetan Plateau Scientific Expedition and Research program(No.2019QZKK0102)。
文摘The Amazon basin plays a crucial role in biodiversity and carbon storage,but its local rainfall is anticipated to decrease under globalwarming.Carbon dioxide removal(CDR)is being considered as a method to mitigate the impact of global warming.However,the specific effects of CDR on Amazon rainfall have not been well understood.Here,an idealized CDR experiment reveals that the reduced rainfall over the Amazon basin does not recover.Significantly weaker rainfall is found during the ramp-down period compared to the ramp-up period at the same CO_(2)concentration.This response is associated with the enhanced El Niño-like warming in the tropical Pacific Ocean during the CDR period.This warming pattern has dual effects:weakening the zonal circulation and causing anomalous descent directly over the Amazon basin,while also triggering a stationary Rossby wave train that propagated downstream and generated anomalous ascent over the Sargasso Sea.This anomalous ascent induces anomalous descent and weakens moisture transport over the Amazon basin by the local meridional circulation.Consequently,precipitation is reduced over the Amazon basin in response to the weakened zonal and meridional circulation.Our findings indicate that even if the atmospheric CO_(2)concentration is lowered,the Amazon basin will remain susceptible to drought.Effective local climate adaptation strategies are urgently needed to address the vulnerability of this critical ecosystem.
基金supported by the National High-Tech R&D Program of China (No. 2008AA06Z318)the Ministry of Environmental Protection of China (Nos. 201009048 and 200909025)
文摘To study the mechanism of SO2 and Hg removal from flue gas, an experimental packed bed reactor was designed to simulate the dry FGD, where a mixture of lime and fly ash in ratio 1：3 w/w was used as the S02 and Hg sorbent, and steam at temperature of 100 ℃ was applied for activation of the sorbent, while the activation time set to 20 rain. The experimental factors including the SO2/Hg sorbent characteristics, 50% breakthrough time for SO2/Hg removal, sorbent packed bed depth and reaction temperature were investigated. The experimental results show that after steam activation, the BET specific surface area and specific pore volume increased from 37.8 to 45.5 m^2/g and from 0.42 to 0.51 cm^3/g, respectively. With activation of the sorbent by steam, the 50% breakthrough times of SO2 and Hg removal increased from 34 to 42 rain and from 23 to 45 rain, respectively. When the packed bed depth was increased from 5 to 25 ram. the 50% breakthrough times for Hg and S02 removal increased from 12 to 52 rain and from 6 to 47 rain, respectively. With the increase of the reaction temperature, the 50% breakthrough of SO2/Hg removal decreased accordingly. Steam activation can efficiently improve SO2/Hg removal simultaneously.
基金National Natural Science Foundation of China(21865011)2024 Innovation and Entrepreneurship Project of College Student in Jishou University(JDCX20241122)。
文摘To remove the fluoride in zinc sulfate electrolyte to an appropriate level,mitigate environmental fluoride pollution,and drive the development of the hydrometallurgy industry of zinc,a novel Fe_(3)O_(4)@SiO_(2)@Fe-MIL-101 magnetic composite material was successfully synthesized via the one-pot method.Preparation conditions were optimized and structural characterization of this material conducted using FTIR,SEM,EDS,XRD and Hysteresis analysis.The results show that this composite exhibits a more rapid fluoride adsorption dynamics and a higher fluoride adsorption capacity(18.34 mg/g)and its adsorption behavior fitted for the first order dynamic model and the Freundlich isotherm model.The adsorption of fluorine by this composite is mainly physical adsorption according to the mean adsorption energy(1.216 kJ/mol).The interfering ions co-existed in fluoride-containing solutions,like HCO_(3)^(-),NO^(-)and Cl^(-),have a significant effect on fluorine adsorption.This composite has also been proved with magnetism,higher adsorption selectivity and satisfactory reusability.When this composite is employed as an adsorbent for adsorption removing fluoride in zinc sulfate electrolyte,it exhibits higher pH-dependent behavior as well as high fluoride removal efficiency at pH 6.5.
基金financially supported by the National Natural Science Foundation of China (No. 51706091)the Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering, MOE of China (No. KLIEEE-18-04)+1 种基金the Talent Scientific Research Fund of LSHU(No. 2018XJJ-011)the PhD Research Startup Foundation of Liaoning Shihua University (No. 2016XJJ-025)
文摘In this study, titanium dioxide supported by multi-walled carbon nano tubes(MWCNTs/TiO_2) and Cr-doped TiO_2 supported by MWCNTs(MWNTs/Cr-TiO_2) were synthesized by the sol-gel method. The prepared samples were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, the BrunauerEmmett-Teller analysis, and the Raman spectroscopy. The oxidation and efficiency for removal of SO_2 in a simulated flue gas were investigated experimentally in a fixed-bed reactor. The 15% MWCNTs/Cr-Ti02 sample displayed excellent adsorption properties, and a SO_2 removal rate equating to 30.415 1 mg/g from the simulated flue gas containing 2 300 μg/g of SO_2, 8% of 02, and 5% of H20 was achieved under optimal conditions covering a temperature of 333.15 K, and a space velocity of 1 275 h^(-1). The adsorption process was enhanced because Cr doping modified the pore structure and inhibited the grain growth of TiO_2. In addition, the Freundlich and Langmuir models revealed that SO_2 was mainly adsorbed through chemical adsorption on the sample surfaces, and the thermodynamic model analysis indicated that the adsorption was a spontaneous, exothermic, and entropy-reducing process. The adsorption kinetics of SO_2 can be described by the pseudosecond-order kinetic and the Bangham dynamics models. The possible reaction mechanism involved in desulfurization process was also proposed.
文摘The dielectric barrier corona discharge(DBCD) in a wire-cylinder configuration and the dielectric barrier discharge(DBD) in a coaxial cylinder configuration are studied. The discharge current in DBD has a higher pulse amplitude than in DBCD. The dissipated power and the gas-gap voltage are calculated by analyzing the measured Lissajous figure. With the increasing applied voltage, the energy utilization factor for SO2 removal increases in DBCD but decreases in DBD because of the difference in their electric field distribution. Experiments of SO2 removal show that in the absence of NH3 the energy utilization factor can reach 31 g/kWh in DBCD and 39 g/kWh in DBD.
文摘The industrial implementation of Solar-driven photocatalysis is hampered by inefficient charge separation,poor reusability and hard retrieval of powdery catalysts.To conquer these drawbacks,a self-floating S-scheme Bi_(4)O_(5)Br_(2)/P-doped C_(3)N_(4)/carbon fiber cloth(BB/PN/CC)composed of carbon fibers(CC)as the core and Bi_(4)O_(5)Br_(2)/P-doped C_(3)N_(4)(BB/PN)nanosheets as the shell was constructed as a competent,recyclable cloth-shaped photocatalyst for safe and efficient degradation of aquacultural antibiotics.The BB/PN/CC fabric achieves an exceptional tetracycline degradation rate constant of 0.0118 min‒1,surpassing CN/CC(0.0015 min^(‒1)),BB/CC(0.0066 min^(‒1))and PN/CC(0.0023 min^(‒1))by 6.9,0.8 and 4.1 folds,respectively.Beyond its catalytic prowess,the photocatalyst’s practical superiority is evident in its effortless recovery and environmental adaptability.The superior catalytic effectiveness stems from the S-scheme configuration,which retains the maximum redox capacities of the constituent BB and PN while enabling efficient spatial detachment of photo-carriers.X-ray photoelectron spectroscopy(XPS),in-situ XPS,and electron paramagnetic resonance analyses corroborate the S-scheme mechanism,revealing electron accumulation on PN and hole retention on BB under illumination.Density functional theory calculations further confirm S-scheme interfacial charge redistribution and internal electric field formation.This study advances the design of macroscopic S-scheme heterojunction photocatalysts for sustainable water purification.
基金the National Science Foundation for Distinguished Young Scholars of China (No.50525722)the Science and Technology research key project of MOE
文摘In this paper, an experimental study on SO2 removal by nanosecond rising edge pulse dielectric barrier discharge （DBD） plasma, generated by multi-needle-to-plane electrodes, is carried out. The mechanism of the effect of various factors, such as gap size between dielectric barrier and discharge needles, environmental humidity, and inlet speed of gas flow upon the removal efficiency of air purification is analyzed. The studies show that SOs removal efficiency improves with the increase in the gap size between dielectric barrier and discharge needles in the case of a fixed space between two electrodes, and also improves with the increase in the environmental humidity. For a mixed gas with a fixed concentration, there is an optimal inlet speed of gas flow, which leads to the best removal efficiency.
基金the Sci.& Tech.research key project of Ministry of Education and National Natural Science Foundation of China (Nos.50477025 and 50537050)
文摘Dielectric barrier discharge （DBD） for SOs removal from indoor air is investigated. In order to improve the removal efficiency, two novel methods are combined in this paper, namely by applying a pulsed driving voltage with nanosecond rising time and applying a magnetic field. For SOs removal efficiency, different matches of electric field and magnetic field are discussed. And nanosecond rising edge pulsed power supply and microsecond rising edge pulsed power supply are compared. It can be concluded that a pulsed DBD with nanosecond rising edge should be adopted, and electrical field and magnetic field should be applied in an appropriate match.
基金National Natural Science Foundation of China(No.50578020)the Project of Jiangsu University High-level Professional Scientific Research Fund(No.05JDG052)Jiangsu Educational Science Key Topics for the"11th Five-Year"Plan(B-b/2006/01/019)
文摘In this study, lime-hydrate （Ca（OH）2） desulfurizer was treated by plasma with strong ionization discharge of a dielectric barrier. The removal of SO2 from simulated flue gas was investigated. The principles of SO2 removal are discussed. Several factors affecting the efficiency of SO2 removal were studied. They included the ratio of calcium to sulfur （Ca/S）, desulfurizer granularity, residence time of the flue gas, voltage applied to the discharge electrode in the plasma generator, and energy consumption. Experimental results indicate that the increase in Ca/S ratio, the applied voltage and discharge power, the residence time, and the reduction in the desulfurizer granularity all can raise the SO2 removal efficiency. The SO2 removal efficiency was up to 91.3% under the following conditions, namely a primary concentration of SO2 of 2262×10^-6 （v/v） in the emission gas, 21%（v/v） of oxygen, 1.8% （v/v） of water, a Ca/S ratio of 1.48, a residence time of 2.8 s, a 3.4 kV voltage and a 10kHz frequency power applied to the discharge electrodes in the plasma generator, and a flow rate of 100 m^3/h for emission gas.
基金supported by the National Natural Science Foundation of China (41503102, 41401567, 41573138)the China Postdoctoral Science Foundation (2015M572568)~~
文摘Hollow Bi2WO6 microspheres are successfully synthesized by a facile ultrasonic spray pyrolysis（USP） method using NaCl as a salt template.The as-prepared hollow microspheres assembled as nanoplates with dimensions of approximately 41-148 nm and are dispersed with non-uniform pores on the template surface.By swapping the salt template with KC1 or Na2SO4,different morphologies of Bi2WO6 are obtained.The experimental results demonstrate that NaCl plays a key role on the formation of Bi2WO6 with hollow structures.The specific growth mechanism of hollow microspheres was studied in detail.The Bi2WO6 hollow microspheres exhibit an excellent photocatalytic efficiency for NO removal under solar light irradiation,which is 1.73 times higher than for the Bi2WO6 obtained in the absence of any salt template.This enhancement can be ascribed to the simultaneous improvement on the surface area and visible light-harvesting ability from the hollow structures.Electron spin resonance（ESR） results suggest that both radicals of ·OH and ·O2^- are involved in the photocatalytic process over the BWO-NaCl sample.The production of ·O2^- radicals offers better durability for NO removal.
