Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio ...Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio of 1:0.5,temperature of 120°C and time of 1 h at Mg^(2+)concentration of 2 mol/L.Spherical flower-like Mg(OH)_(2) composed of ultra-thin sheets exhibits an excellent adsorption ability for Ni^(2+),Cu^(2+),Zn^(2+),Pb^(2+),Fe^(3+)and Co^(2+),and the adsorption reaches the equilibrium in 6 min.The maximum adsorption capacities of the studied heavy metal ions onto Mg(OH)_(2) at 20°C are 58.55,85.84,44.94,485.44,625.00 and 27.86 mg/g,respectively.The adsorption is well fitted by the Langmuir model,indicating that the adsorption is monolayer.The adsorption kinetics follows the pseudo-second-order model.Chemisorption is the operative mechanism.Spherical flower-like Mg(OH)_(2) is a qualified candidate for heavy metal ions removal.展开更多
The interaction between several different metal ions and H2O along with CO2 has been researched theoretically in the CO2 photocatalytic reduction with H2O system at the B3LYP level by DFT.The computational results rev...The interaction between several different metal ions and H2O along with CO2 has been researched theoretically in the CO2 photocatalytic reduction with H2O system at the B3LYP level by DFT.The computational results revealed that relatively high valence metal ions loaded on TiO2 activated the H2O and CO2 consumingly,and it might be looked as some proofs for modified photocatalyst selecting.In addition,the metal ions conducted photoelectrons to prevent the re-combination of photoelectrons and holes during the reaction process.展开更多
1 IntrodutionInterleukin-2(IL-2)was found to selectively keep growth of T lymphocytes for longperiod in vitro in 1976,and was then named T cell growth factor,TCGF.After that,IL-2 was found to promote proliferation of ...1 IntrodutionInterleukin-2(IL-2)was found to selectively keep growth of T lymphocytes for longperiod in vitro in 1976,and was then named T cell growth factor,TCGF.After that,IL-2 was found to promote proliferation of various cells,mainly including T,B,NK,and to in-crease activity of T cell and NK cell.Discovery of its surprising effect in treatment of can-cer,tumor through inducing LAK(lymphokine-activated killer cells)or activating TIL(tumor infiltrated lymphocytes)to kill cancer cell made it very attractive.Therefore it wasfound a wide application in therapy of cancer,immunodeficiency and diseases relating toinfection.However,in its application,problem was found that it had very serious side-effect,and very high dose made the side effect even more serious.The aim of this study was to find a simple way to stabilize IL-2 so as to lower the doserequired in application and in turn to solve the problem.展开更多
Recently, Hsieh and Horng [1] published the paper entitled as above. In section 3 results and discussion, the authors mentioned the first and the second order kinetic models without any quotations. In fact these two k...Recently, Hsieh and Horng [1] published the paper entitled as above. In section 3 results and discussion, the authors mentioned the first and the second order kinetic models without any quotations. In fact these two kinetic models have been published [2-5]. In order to distinguish a kinetics model based on the ad- sorption capacity of a solid from the one based on the concentration of a solution, Lagergren＇s first-order rate equation has been called pseudo-first-order [6-7]. The Lagergren＇s equation has been widely cited, but there are far more mistakes made in the quotation and in the reference section of papers, including the title, the author＇s name, journal title, year of publishing, volume, and page number [3]. In addition, the second order kinetic expression for the adsorption systems of divalent metal ions using sphagnum moss peat has been reported by Ho [8].展开更多
2,2’-Bithiophene-5-carboxylic acid (BTA) thin-films on platinum (Pt) electrodes were electrochemically prepared in acetonitrile solution containing 0.1 M tetrabutylammonium perchlorate (TBAP) and 0.05 M BTA. These fi...2,2’-Bithiophene-5-carboxylic acid (BTA) thin-films on platinum (Pt) electrodes were electrochemically prepared in acetonitrile solution containing 0.1 M tetrabutylammonium perchlorate (TBAP) and 0.05 M BTA. These films were complexes with several metal ions such as Cu2+, Ag+ and Co2+. Their structural characteristics were compared with those of powder complexes chemically prepared from BTA and the corresponding metal ion. IR and XPS techniques reveal that the film complexes with metal ions have the same structures as the corresponding powder complexes. The electrocatalytic activity of BTA film-metal ions has been investigated toward ascorbic acid (AA) oxidation and compared to that obtained on a free BTA film. BTA film-metal ions exhibit good catalytic proprieties and better detection of AA than a free BTA film. This new propriety allows these films to be used as electrochemical sensors. This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.展开更多
The photocatalytic degradation of dyes （Acid Chrome Blue K （ACBK） and Alizarin Red （AR）） with strong complexation ability was investigated in the presence of metal ions under visible light irradiation. It was fo...The photocatalytic degradation of dyes （Acid Chrome Blue K （ACBK） and Alizarin Red （AR）） with strong complexation ability was investigated in the presence of metal ions under visible light irradiation. It was found that, at low dye-metal ratio, the photodegradation of ACBK was markedly inhibited by the addition of high oxidative potential Cu2＋. However, at high dye-metal ratio, the presence of Cu2＋ enhanced the photodegradation of ACBK. The negtive effect of Cu2＋ on the photodegradation of AR was observed for all dyemetal ratios. The relative chemical inert Zn2＋ tended to enhance the photodegradation of both anionic dyes. The mechanism underlying the different effect of Cu2＋ was discussed from the different roles of surface-adsorbed and dye-coordinated Cu2＋ in the photodegradation of dyes.展开更多
Zeolite X was synthesized by a two-step hydrothermal method using natural stellerite zeolite as the silicon seed,and its adsorption performance for Cd^(2+)and Ni^(2+)ions was experimentally and comprehensively investi...Zeolite X was synthesized by a two-step hydrothermal method using natural stellerite zeolite as the silicon seed,and its adsorption performance for Cd^(2+)and Ni^(2+)ions was experimentally and comprehensively investigated.The effects of p H,zeolite X dosage,contact time,and temperature on adsorption performance for Cd^(2+)and Ni^(2+)ions over were studied.The adsorption process was endothermic and spontaneous,and followed the pseudo-second-order kinetic and the Langmuir isotherm models.The maximum adsorption capacitiesfor Cd^(2+)and Ni^(2+)ions at 298 K were 173.553 and 75.897 mg.g-1,respectively.Ion exchange and precipitation were the principal mechanisms for the removal of Cd^(2+)ions from aqueous solutions by zeolite X,followed by electrostatic adsorption.Ion exchange was the principal mechanisms for the removal of Ni^(2+)ions from aqueous solutions by zeolite X,followed by electrostatic adsorption and precipitation.The zeolite X converted from stellerite zeolite has a low n(Si/Al),abundant hydroxyl groups,and high crystallinity and purity,imparting a good adsorption performance for Cd^(2+)and Ni^(2+)ions.This study suggests that zeolite X converted from stellerite zeolite could be a useful environmentally-friendly and effective tool for the removal of Cd^(2+)and Ni^(2+)ions from aqueous solutions.展开更多
To maximize the potential of monolayer molybdenum disulfide(MoS2)sheet in the disposal of heavy metal ions in wastewater,we compared the adsorption of several common heavy metal ions(including Cr^(3+),Ni^(2+),Cu^(2+),...To maximize the potential of monolayer molybdenum disulfide(MoS2)sheet in the disposal of heavy metal ions in wastewater,we compared the adsorption of several common heavy metal ions(including Cr^(3+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),and Pb^(2+))in wastewater on the monolayer MoS2 sheet through first-principles calculation.Our simulation results show that the monolayer MoS2 sheet is a potential heavy metal adsorption material because of the attractive interaction between them.The most negative adsorption energy determines that the TMo site is the most stable adsorption site for the heavy metal ions.The attractive interaction is considered as chemical adsorption,and it is closely related to charge transfer.The orbital hybridization between S p and heavy metal ions p and d states electrons contributes to the adsorption,except the orbital hybridization between S p and Pb p states electrons contributes to the Pb^(2+) adsorption.All the results show that the monolayer MoS2 sheet is most suitable for removing Ni^(2+) and Cr^(3+) ions from wastewater,followed by Cu^(2+) and Pb^(2+).For the ions Cd^(2+),Zn^(2+),and Hg^(2+),its adsorption strength remains to be improved.展开更多
The presence of silver ions(Ag(I))in wastewater has a detrimental effect on living organisms.Removal of soluble silver,especially at low concentrations,is challenging.This paper presents the use ofβ-MnO2 particles as...The presence of silver ions(Ag(I))in wastewater has a detrimental effect on living organisms.Removal of soluble silver,especially at low concentrations,is challenging.This paper presents the use ofβ-MnO2 particles as a photocatalyst to remove Ag(I)ions selectively from aqueous solution at various pH levels.Inductively coupled plasma mass spectrometry(ICP-MS),X-ray diffraction(XRD),field emission electron microscope(FESEM),transmission electron microscopy(TEM),and X-ray photoelectron microscopy(XPS)were employed to determine the removal efficiency and to characterize the deposition of silver onto the surface ofβ-MnO2 particles.The optimum pH for the removal of Ag(I)ions was at pH 4 with 99%removal efficiency under 1 h of visible light irradiation.This phenomenon can be attributed to the electrostatic attraction betweenβ-MnO2 particles and Ag(I)ions as well as the suppression of electron–hole recombination in the presence of H+ions.展开更多
An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved....An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the? values from the extraction-experimentally obtained logKD,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, KD,Pic, denotes an individual distribution constant of Pic﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the? terms in their functional expressions.展开更多
Li-rich layered oxide(LRLO)cathodes have been regarded as promising candidates for next-generation Li-ion batteries due to their exceptionally high energy density,which combines cationic and anionic redox activities.H...Li-rich layered oxide(LRLO)cathodes have been regarded as promising candidates for next-generation Li-ion batteries due to their exceptionally high energy density,which combines cationic and anionic redox activities.However,continuous voltage decay during cycling remains the primary obstacle for practical applications,which has yet to be fundamentally addressed.It is widely acknowledged that voltage decay originates from the irreversible migration of transition metal ions,which usually further exacerbates structural evolution and aggravates the irreversible oxygen redox reactions.Recently,constructing O2-type structure has been considered one of the most promising approaches for inhibiting voltage decay.In this review,the relationship between voltage decay and structural evolution is systematically elucidated.Strategies to suppress voltage decay are systematically summarized.Additionally,the design of O2-type structure and the corresponding mechanism of suppressing voltage decay are comprehensively discussed.Unfortunately,the reported O2-type LRLO cathodes still exhibit partially disordered structure with extended cycles.Herein,the factors that may cause the irreversible transition metal migrations in O2-type LRLO materials are also explored,while the perspectives and challenges for designing high-performance O2-type LRLO cathodes without voltage decay are proposed.展开更多
Extraction of heavy metal ions from solid matrix by means of an incorporation of chelating agents with supercritical carbon dioxide（scCO2） was investigated experimentally. Four commercially available chelating agent...Extraction of heavy metal ions from solid matrix by means of an incorporation of chelating agents with supercritical carbon dioxide（scCO2） was investigated experimentally. Four commercially available chelating agents, diethylammonium diethyldithiocarbamate（Et2NH2DDC）, trifluoroacetylacetone（TFA）, hexafluoroacetylacetone（HFA） and thenoyltrifluoroacetone（TTA） were tested. The extraction experiments were conducted at 50 °C and 1.39×107― 2.80×107 Pa. According to the experimental results, for the extraction of Cu2＋, all the chelating agents investigated here are effective. For other metal ions, such as Pb2＋, Ni2＋ and Cd2＋, Et2NH2DDC exhibited a better extraction result, while other chelating agents were less effective. This investigation is expected to provide a tentative evaluation on the scCO2-based metal extraction from solid media.展开更多
Two systems of La_(2-x)Sr_xCuO_(4±λ) and La_(2-x)Th_xCuO_(4±λ) mixed oxides with K_2NiF_4structure were synthesized.The compositions and structures of the catalysts were characterized by means of XRD,XPS,c...Two systems of La_(2-x)Sr_xCuO_(4±λ) and La_(2-x)Th_xCuO_(4±λ) mixed oxides with K_2NiF_4structure were synthesized.The compositions and structures of the catalysts were characterized by means of XRD,XPS,chemical analysis and so on.The catalytic behavior for the direct decomposition of NO has been investigated.The results show that the catalytic activity is closely related to the oxygen vacancy and lower valence metallic ion in the direct decomposition of NO.The presence of oxygen vacancy is necessary for mixed oxide to have steady activity in NO decomposition.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 51774070 and 52004165)the Science and Technology Project of Yunnan Province, China (No. 202101AS070029)
文摘Spherical flower-like Mg(OH)_(2) was fabricated from MgSO_(4) effluent and its adsorption performance for heavy metal ions was evaluated.The appropriate fabrication conditions are as follows:Mg^(2+)/NH4OH molar ratio of 1:0.5,temperature of 120°C and time of 1 h at Mg^(2+)concentration of 2 mol/L.Spherical flower-like Mg(OH)_(2) composed of ultra-thin sheets exhibits an excellent adsorption ability for Ni^(2+),Cu^(2+),Zn^(2+),Pb^(2+),Fe^(3+)and Co^(2+),and the adsorption reaches the equilibrium in 6 min.The maximum adsorption capacities of the studied heavy metal ions onto Mg(OH)_(2) at 20°C are 58.55,85.84,44.94,485.44,625.00 and 27.86 mg/g,respectively.The adsorption is well fitted by the Langmuir model,indicating that the adsorption is monolayer.The adsorption kinetics follows the pseudo-second-order model.Chemisorption is the operative mechanism.Spherical flower-like Mg(OH)_(2) is a qualified candidate for heavy metal ions removal.
基金Supported by the Natural Science Foundation of Jiangxi Province (Nos. 0220006 and 2007GZH2643)
文摘The interaction between several different metal ions and H2O along with CO2 has been researched theoretically in the CO2 photocatalytic reduction with H2O system at the B3LYP level by DFT.The computational results revealed that relatively high valence metal ions loaded on TiO2 activated the H2O and CO2 consumingly,and it might be looked as some proofs for modified photocatalyst selecting.In addition,the metal ions conducted photoelectrons to prevent the re-combination of photoelectrons and holes during the reaction process.
文摘1 IntrodutionInterleukin-2(IL-2)was found to selectively keep growth of T lymphocytes for longperiod in vitro in 1976,and was then named T cell growth factor,TCGF.After that,IL-2 was found to promote proliferation of various cells,mainly including T,B,NK,and to in-crease activity of T cell and NK cell.Discovery of its surprising effect in treatment of can-cer,tumor through inducing LAK(lymphokine-activated killer cells)or activating TIL(tumor infiltrated lymphocytes)to kill cancer cell made it very attractive.Therefore it wasfound a wide application in therapy of cancer,immunodeficiency and diseases relating toinfection.However,in its application,problem was found that it had very serious side-effect,and very high dose made the side effect even more serious.The aim of this study was to find a simple way to stabilize IL-2 so as to lower the doserequired in application and in turn to solve the problem.
文摘Recently, Hsieh and Horng [1] published the paper entitled as above. In section 3 results and discussion, the authors mentioned the first and the second order kinetic models without any quotations. In fact these two kinetic models have been published [2-5]. In order to distinguish a kinetics model based on the ad- sorption capacity of a solid from the one based on the concentration of a solution, Lagergren＇s first-order rate equation has been called pseudo-first-order [6-7]. The Lagergren＇s equation has been widely cited, but there are far more mistakes made in the quotation and in the reference section of papers, including the title, the author＇s name, journal title, year of publishing, volume, and page number [3]. In addition, the second order kinetic expression for the adsorption systems of divalent metal ions using sphagnum moss peat has been reported by Ho [8].
文摘2,2’-Bithiophene-5-carboxylic acid (BTA) thin-films on platinum (Pt) electrodes were electrochemically prepared in acetonitrile solution containing 0.1 M tetrabutylammonium perchlorate (TBAP) and 0.05 M BTA. These films were complexes with several metal ions such as Cu2+, Ag+ and Co2+. Their structural characteristics were compared with those of powder complexes chemically prepared from BTA and the corresponding metal ion. IR and XPS techniques reveal that the film complexes with metal ions have the same structures as the corresponding powder complexes. The electrocatalytic activity of BTA film-metal ions has been investigated toward ascorbic acid (AA) oxidation and compared to that obtained on a free BTA film. BTA film-metal ions exhibit good catalytic proprieties and better detection of AA than a free BTA film. This new propriety allows these films to be used as electrochemical sensors. This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.
基金supported by the Ministry of Science and Technology of China (No. 2007AA061402)the National Natural Science Foundation of China (No. 20537010,20772129)the Chinese Academy of Sciences.
文摘The photocatalytic degradation of dyes （Acid Chrome Blue K （ACBK） and Alizarin Red （AR）） with strong complexation ability was investigated in the presence of metal ions under visible light irradiation. It was found that, at low dye-metal ratio, the photodegradation of ACBK was markedly inhibited by the addition of high oxidative potential Cu2＋. However, at high dye-metal ratio, the presence of Cu2＋ enhanced the photodegradation of ACBK. The negtive effect of Cu2＋ on the photodegradation of AR was observed for all dyemetal ratios. The relative chemical inert Zn2＋ tended to enhance the photodegradation of both anionic dyes. The mechanism underlying the different effect of Cu2＋ was discussed from the different roles of surface-adsorbed and dye-coordinated Cu2＋ in the photodegradation of dyes.
基金supported by the National Natural Science Foundation of China(51564008,41662005)Natural Science Foundation of Guangxi Province(2019GXNSFBA245083)。
文摘Zeolite X was synthesized by a two-step hydrothermal method using natural stellerite zeolite as the silicon seed,and its adsorption performance for Cd^(2+)and Ni^(2+)ions was experimentally and comprehensively investigated.The effects of p H,zeolite X dosage,contact time,and temperature on adsorption performance for Cd^(2+)and Ni^(2+)ions over were studied.The adsorption process was endothermic and spontaneous,and followed the pseudo-second-order kinetic and the Langmuir isotherm models.The maximum adsorption capacitiesfor Cd^(2+)and Ni^(2+)ions at 298 K were 173.553 and 75.897 mg.g-1,respectively.Ion exchange and precipitation were the principal mechanisms for the removal of Cd^(2+)ions from aqueous solutions by zeolite X,followed by electrostatic adsorption.Ion exchange was the principal mechanisms for the removal of Ni^(2+)ions from aqueous solutions by zeolite X,followed by electrostatic adsorption and precipitation.The zeolite X converted from stellerite zeolite has a low n(Si/Al),abundant hydroxyl groups,and high crystallinity and purity,imparting a good adsorption performance for Cd^(2+)and Ni^(2+)ions.This study suggests that zeolite X converted from stellerite zeolite could be a useful environmentally-friendly and effective tool for the removal of Cd^(2+)and Ni^(2+)ions from aqueous solutions.
基金This work was supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U1967212)the National Science and Technology Major Project of China(Grant No.2019XS06004009)the Fundamental Research Funds for the Central Universities(Grant No.2018ZD10).
文摘To maximize the potential of monolayer molybdenum disulfide(MoS2)sheet in the disposal of heavy metal ions in wastewater,we compared the adsorption of several common heavy metal ions(including Cr^(3+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),and Pb^(2+))in wastewater on the monolayer MoS2 sheet through first-principles calculation.Our simulation results show that the monolayer MoS2 sheet is a potential heavy metal adsorption material because of the attractive interaction between them.The most negative adsorption energy determines that the TMo site is the most stable adsorption site for the heavy metal ions.The attractive interaction is considered as chemical adsorption,and it is closely related to charge transfer.The orbital hybridization between S p and heavy metal ions p and d states electrons contributes to the adsorption,except the orbital hybridization between S p and Pb p states electrons contributes to the Pb^(2+) adsorption.All the results show that the monolayer MoS2 sheet is most suitable for removing Ni^(2+) and Cr^(3+) ions from wastewater,followed by Cu^(2+) and Pb^(2+).For the ions Cd^(2+),Zn^(2+),and Hg^(2+),its adsorption strength remains to be improved.
基金This study was funded by Universiti Sains Malaysia, ResearchUniversity Grant (1001.PBAHAN.8014095). The authorsalso acknowledge the support from USM Fellowship.
文摘The presence of silver ions(Ag(I))in wastewater has a detrimental effect on living organisms.Removal of soluble silver,especially at low concentrations,is challenging.This paper presents the use ofβ-MnO2 particles as a photocatalyst to remove Ag(I)ions selectively from aqueous solution at various pH levels.Inductively coupled plasma mass spectrometry(ICP-MS),X-ray diffraction(XRD),field emission electron microscope(FESEM),transmission electron microscopy(TEM),and X-ray photoelectron microscopy(XPS)were employed to determine the removal efficiency and to characterize the deposition of silver onto the surface ofβ-MnO2 particles.The optimum pH for the removal of Ag(I)ions was at pH 4 with 99%removal efficiency under 1 h of visible light irradiation.This phenomenon can be attributed to the electrostatic attraction betweenβ-MnO2 particles and Ag(I)ions as well as the suppression of electron–hole recombination in the presence of H+ions.
文摘An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the? values from the extraction-experimentally obtained logKD,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, KD,Pic, denotes an individual distribution constant of Pic﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the? terms in their functional expressions.
基金funded by the National Natural Science Foundation of China(Grant Nos.22279092 and 5202780089).
文摘Li-rich layered oxide(LRLO)cathodes have been regarded as promising candidates for next-generation Li-ion batteries due to their exceptionally high energy density,which combines cationic and anionic redox activities.However,continuous voltage decay during cycling remains the primary obstacle for practical applications,which has yet to be fundamentally addressed.It is widely acknowledged that voltage decay originates from the irreversible migration of transition metal ions,which usually further exacerbates structural evolution and aggravates the irreversible oxygen redox reactions.Recently,constructing O2-type structure has been considered one of the most promising approaches for inhibiting voltage decay.In this review,the relationship between voltage decay and structural evolution is systematically elucidated.Strategies to suppress voltage decay are systematically summarized.Additionally,the design of O2-type structure and the corresponding mechanism of suppressing voltage decay are comprehensively discussed.Unfortunately,the reported O2-type LRLO cathodes still exhibit partially disordered structure with extended cycles.Herein,the factors that may cause the irreversible transition metal migrations in O2-type LRLO materials are also explored,while the perspectives and challenges for designing high-performance O2-type LRLO cathodes without voltage decay are proposed.
基金Supported by the National Natural Science Foundation of China(Nos.20776066, 20976079)
文摘Extraction of heavy metal ions from solid matrix by means of an incorporation of chelating agents with supercritical carbon dioxide（scCO2） was investigated experimentally. Four commercially available chelating agents, diethylammonium diethyldithiocarbamate（Et2NH2DDC）, trifluoroacetylacetone（TFA）, hexafluoroacetylacetone（HFA） and thenoyltrifluoroacetone（TTA） were tested. The extraction experiments were conducted at 50 °C and 1.39×107― 2.80×107 Pa. According to the experimental results, for the extraction of Cu2＋, all the chelating agents investigated here are effective. For other metal ions, such as Pb2＋, Ni2＋ and Cd2＋, Et2NH2DDC exhibited a better extraction result, while other chelating agents were less effective. This investigation is expected to provide a tentative evaluation on the scCO2-based metal extraction from solid media.
文摘Two systems of La_(2-x)Sr_xCuO_(4±λ) and La_(2-x)Th_xCuO_(4±λ) mixed oxides with K_2NiF_4structure were synthesized.The compositions and structures of the catalysts were characterized by means of XRD,XPS,chemical analysis and so on.The catalytic behavior for the direct decomposition of NO has been investigated.The results show that the catalytic activity is closely related to the oxygen vacancy and lower valence metallic ion in the direct decomposition of NO.The presence of oxygen vacancy is necessary for mixed oxide to have steady activity in NO decomposition.
