The availability of chemical and biological data presented in this paper is the basis for understanding not only the current state of anti-cancer drugs based on gold(Ⅲ),but also the rationale for strategies for futur...The availability of chemical and biological data presented in this paper is the basis for understanding not only the current state of anti-cancer drugs based on gold(Ⅲ),but also the rationale for strategies for future drug design.New Au(Ⅲ)nanosized complexes of cefotaxime(ceph-3)and cefepime(ceph-4)ligands as a 3rd and 4th of cephalosporin generation drugs were synthesized.Gold(Ⅲ)complexes were discussed based on the elemental,molar conductance,thermal and magnetic moment measurements as well as spectral(FTIR,1HNMR,UV-Vis,and XRD)techniques.FT-IR spectra revealed that the ceph-3 and ceph-4 ligands reacted as a bidentate ligands through carboxylate oxygen andβ-lactam oxygen groups.The analytical analysis confirm that the molar ratio is 1∶1(Au 3+/ceph)with general formula[Au(L)(Cl)2]where L=ceph-3 or ceph-4.The structures of Au(Ⅲ)complexes were presence as a square planar geometry.X-ray diffraction patterns referred to a crystalline nature for all synthesized complexes.TEM analyses confirmed that the synthetic gold(Ⅲ)complexes have a nanosized particles.In vitro antimicrobial activities of Au(Ⅲ)complexes were evaluated towards two types of bacteria(G+&G-).The antitumor activities of gold(Ⅲ)complexes are appraised against breast(MCF-7)and colorectal adenocarcinoma(Caco-2)cell lines,which means that the two complexes may consider promising anticancer drugs.展开更多
The spherical macroporous cellulose(SMC) was fabricated using medical absorbent cotton as raw material and nano CaCO3 as porogenic agents.And then,the phenylglycine was grafted onto the SMC to obtain the novel spheric...The spherical macroporous cellulose(SMC) was fabricated using medical absorbent cotton as raw material and nano CaCO3 as porogenic agents.And then,the phenylglycine was grafted onto the SMC to obtain the novel spherical macroporous cellulose derivative adsorbent(PSMC).FT-IR and scanning electron microscope(SEM) were employed to characterize the adsorbents and Fe3+ ions served as model solute to evaluate the adsorption property of the adsorbents.The experimental results show that the amount of porogenic agents and the value of pH have obvious influence on adsorption capacity of the adsorbents.The data of adsorption kinetic and isotherm display that the adsorbents possess excellent equilibrium adsorption capacity(348.94 mg/g) and have a bright prospect and considerable potential in the treatment of Fe3+ ions in wastewater.展开更多
A variety of gold(Ⅲ) adducts having a-ligated oxygen-donor ligands have been prepared from [Au(ppy)Cl2](ppy.phenylpyridine)(1) either by partial or total replacement of the chloride ions. The new species comp...A variety of gold(Ⅲ) adducts having a-ligated oxygen-donor ligands have been prepared from [Au(ppy)Cl2](ppy.phenylpyridine)(1) either by partial or total replacement of the chloride ions. The new species comprise hydroxo-[Au(ppy)(OH)Cl](2), and [Au(ppy)(OH)2](3), oxo-[Au2(ppy)2(μ-O)2](4), acetate-[Au(ppy)(O2CMe2)] (5), and alkoxo complexes-[Au(ppy)(OR)Cl](6, 7) and [Au(ppy)(OR)2](8--10)(R=Me, 6 and 8; Et, 7 and 9; Pr, 10). The dihydroxo and the oxo complexes can be interconverted by refluxing the former in anhydrous THF and the latter in water. The hydroxides 2 and 3 and the acetato complex 5 undergo σ-ligand metathesis in ROH solution(R=Me, Et or Pr) to give the corresponding alkoxides.展开更多
The electrooxidation of hydrogen on platinum and gold electrodes is comparatively described in this paper. The reaction is faster on platinum than on the gold surface, because the reactive diffuses inside of the gold ...The electrooxidation of hydrogen on platinum and gold electrodes is comparatively described in this paper. The reaction is faster on platinum than on the gold surface, because the reactive diffuses inside of the gold metal. This process is complicated with the lift of surface reconstruction of the (100) plane, which allows the fast penetration of the H atoms through the more open surface. The diffusion limiting current is then discontinued and the current falls. On platinum, the current fall occurs simultaneously with the metal oxide formation. It is assumed that the hydrogen helps the adsorbed OH group formation, which is the first step of metal oxidation, and it has been called “incipient hydrous oxide” (IHO). Current begins to fall slowly at the (IHO) potential. At higher potential the current falls abruptly.展开更多
Humic substances are ubiquitous redox-active organic compounds of environment. In this study, experiments were conducted to determine the reduction capacity of humic acid in the man-ix of bromate and Fe(Ⅲ) solution...Humic substances are ubiquitous redox-active organic compounds of environment. In this study, experiments were conducted to determine the reduction capacity of humic acid in the man-ix of bromate and Fe(Ⅲ) solutions and the role of Fe(Ⅲ) in this redox process. The results showed that the humic acid regenerated Fe(Ⅱ) and reduced bromate abiotically. The addition of Fe(Ⅲ) could accelerate the bromate reduction rate by forming humic acid-Fe(Ⅲ) complexes. Iron species acts as electron mediator and catalyst for the bromate reduction by humic acid, in which humic acid transfers electrons to the complexed Fe(Ⅲ) to form Fe(Ⅱ), and the regenerated Fe(Ⅱ) donate the electrons to bromate. The kinetics study on bromate reduction further indicated that bromate reduction by humic acid-Fe(Ⅲ) complexes is pH dependent. The rate decreased by 2-fold with the increase in solution pH by one unit. The reduction capacity of Aldrich humic acid was observed to be lower than that of humic acid or natural organic matter of Suwanne River, indicating that such redox process is expected to occur in the environment.展开更多
A DNA biosensor with [Ru(DA-bpy)3]Cl2(DA-bpy:4,4'-diamino-2,2'-bipyridine) (RuL) as the electrochemical probe was prepared on pyrolytic graphite electrode (PGE) through the supramolecular interaction betwee...A DNA biosensor with [Ru(DA-bpy)3]Cl2(DA-bpy:4,4'-diamino-2,2'-bipyridine) (RuL) as the electrochemical probe was prepared on pyrolytic graphite electrode (PGE) through the supramolecular interaction between RuL complex and DNA template. Cyclic voltammetry of RuL-DNA film showed a pair of stable and reversible peaks corresponding to the Ru(Ⅲ)/Ru(Ⅲ) redox potential of-0.165 V versus AglAgCl in pa 7.4 0.1 mol·L^-1Tris-HCl. The electron transfer was expected across the double-strand DNA by an "electron tunneling" mechanism. When the DNA biosensor was immerged in gold (Ⅲ) buffer solution, the current peak signal (I) of the RuL-DNA supramolecular depressed and △I was linear in the concentration range of Au ion from 1×10^-7 to 2×10^-5 mol·L^-1 with a regression coefficient of 0.9879. The detection limit was 5×10^-8 mol·L^-1. The developed procedures were applied to the analysis of synthetic samples of real materials with good sensitivity and selectivity.展开更多
The new catalytic kinetic spectrophotometric method for Au(III) determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate ...The new catalytic kinetic spectrophotometric method for Au(III) determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate ((NH4)2S2O8) with nitrilo triacetic acid as an activator in microemulsion and H2SO4 medium. Under optimum conditions, there was the linearity of the calibration curve in the concentration range from 0 to 20 μg/L Au(Ⅲ) at 520 nm. The relative standard deviation was 3.0% with a correlation coefficient of 0.9986. The detection limit achieved was 9.75 × 10^-5 μg/mL. A new method using a column packed with sulfhydryl dextrose gel (SDG) as a solid-phase extractant has been developed for the preconcentration and separation of Au(Ⅲ) ions. The method has been applied to the determination of trace gold with satisfactory results.展开更多
In this study, the kinetics and mechanism of the iridium( Ⅲ ) -catalyzed oxidation of ethanol amine(EAN) by cerium(Ⅳ) in a sulfuric acid medium was investigated using titrimetric technique of redox in a temper...In this study, the kinetics and mechanism of the iridium( Ⅲ ) -catalyzed oxidation of ethanol amine(EAN) by cerium(Ⅳ) in a sulfuric acid medium was investigated using titrimetric technique of redox in a temperature range of 298--313 K. It was found that the reaction is of first order with respect to Ce( Ⅳ ) and It( Ⅲ ), and a positive fractional order with respect to EAN. It was also found that the pseudo-first-order ( [EAN ] 〉〉 [ Ce ( Ⅳ) ] ) rate constant koba decreases with the increase of [ H^+ ] and [ HSO^-4 ]. Under the protection of nitrogen gas, the reaction system can initiate the polymerization of acrylonitrile, indicating the generation of free radicals. On the basis of the experimental results, a suitable mechanism was proposed. From the dependence of koba on the concentration of hydrogen sulfate, Ce(SO4)2 was found to be the kinetically active species. The rate constants of the rote-determining step together with the activation parameters were evaluated.展开更多
The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticat...The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticated in production.The experimental result shows that with different samples and leaching systems,the adaptability and Cl- tolerance of bacteria are different,and that appropriate chloride ion concentration is conductive to bacterial oxidation,while higher chloride ion concentration will inhibit the bacterial activity and affect the pre-oxidation performance.Under the present production conditions,TCJ can adapt to the changes of water quality in the source of water and its critical chloride ion tolerance value is 2.7 g/L.展开更多
The mechanism of adsorbing indium(Ⅲ) from sulfate solutions with CL-P204Levextrel resin containing di(-2-ethylhexyl) phosphoric acid was examined by batch operation andinfrared spectra. The results showed that the P2...The mechanism of adsorbing indium(Ⅲ) from sulfate solutions with CL-P204Levextrel resin containing di(-2-ethylhexyl) phosphoric acid was examined by batch operation andinfrared spectra. The results showed that the P204 adsorbed on the resin behaved in the similar wayto solvent extraction except that it was as a monomer in resin adsorbing but in dimeric form insolvent extraction. Three factors including temperature, indium(Ⅲ) concentration of solution, andthe size of resin particles which influence the In^(3+)/H^+ exchange on CL-P204 Levextrel resin wereinvestigated by the modified limited batch technique in order to determine the kinetics ofIn^(3+)/H^+ exchange. It was found that the rate of ion exchange increased with the temperature andthe concentration of solution increasing and with the size of the resin particles decreasing.According to the expression developed by Boyd et al., the controlling factor of In^(3+)/H^+ exchangeon CL-P204 Levextrel resin was the diffusion through the resin particles. The effective diffusioncoefficient, activation energy, and entropy of activation in the particle-diffusion were determinedas 1.57 x 10^(-10) m^2/s, 11.9 kJ/mol, -84.1 J/(mol·K), respectively.展开更多
Electroreduction of Co(Ⅱ)to metallic cohalt in urea melt is irrevsible in one step.The transfer coeffi-cient of electrode reaction of Co(Ⅱ)+2e=Co(O)and the diffusion coefficient of Co(Ⅱ)were determined.The lanthanu...Electroreduction of Co(Ⅱ)to metallic cohalt in urea melt is irrevsible in one step.The transfer coeffi-cient of electrode reaction of Co(Ⅱ)+2e=Co(O)and the diffusion coefficient of Co(Ⅱ)were determined.The lanthanum can be inductively codeposited with cobalt. The contents of lanthanum in cobalt-lanthanum de-posts increase with the shift of electrode potential to the negative direction and the raise of La(Ⅲ)/Co(Ⅱ)mo-lar ratio in the melt. The cyclic voltammetry,open circuit potential-time curve after potentiostatic electrolysisand electron probe analyas were used.展开更多
The adsorption characteristics of rare earth ion La(Ⅲ) on Yunnan bowl tea surface from aqueous solution and effects of various surfactants on the adsorption were studied. It was found that Yunnan bowl tea can adsorb ...The adsorption characteristics of rare earth ion La(Ⅲ) on Yunnan bowl tea surface from aqueous solution and effects of various surfactants on the adsorption were studied. It was found that Yunnan bowl tea can adsorb strongly La(Ⅲ) and pH may affect drastically the adsorption amount of La(Ⅲ). The adsorption law of La(Ⅲ) on Yunnan bowl tea surface follows the Langmuir equation. The maximum adsorption amount of La(Ⅲ) can reach 15 mg·g (-1). A comprehensive adsorption model is suggested according to the experimental results.展开更多
A rapid synthesis of size-controlled gold nanoparticles was proposed.The method is based on the sensitive intramolecular photoreduction reaction of Fe(Ⅲ)-EDTA complex in chloroacetic acid-sodium acetate buffer solu...A rapid synthesis of size-controlled gold nanoparticles was proposed.The method is based on the sensitive intramolecular photoreduction reaction of Fe(Ⅲ)-EDTA complex in chloroacetic acid-sodium acetate buffer solution,where Fe(Ⅱ)-EDTA complex generated by photo-promotion acts as a reductant of AuCl-4 ions.Gold nanoparticles formed were stabilized by EDTA ligand or other protective agents added.As a result,well-dispersed gold nanoparticles with an average diameter range of 6.7 to 50.9 nm were obtained.According to the characterizations by the UV spectrum and TEM,the intramolecular charge transfer of the excited states of complex Fe(Ⅲ)-EDTA and the mechanism of forming gold nanoparticles were discussed in detail.展开更多
The adsorption of Fe(Ⅲ)ions from aqueous solution by chitosan alpha-ketoglutaric acid(KCTS)and hydroxamated chitosan alpha-ketoglutaric acid(HKCTS)was studied in a batch adsorption system.Experiments were carried out...The adsorption of Fe(Ⅲ)ions from aqueous solution by chitosan alpha-ketoglutaric acid(KCTS)and hydroxamated chitosan alpha-ketoglutaric acid(HKCTS)was studied in a batch adsorption system.Experiments were carried out as function of pH,temperature,agitation rate and concentration of Fe(Ⅲ)ions.The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and isotherm constants were determined.The Langmuir model agrees very well with experimental data.The pseudo-first-order a...展开更多
The interaction between electrode materials and charge carriers is one of the central issues dominating underlying energy storage mechanisms.To address the notoriously significant volume changes accompanying intercala...The interaction between electrode materials and charge carriers is one of the central issues dominating underlying energy storage mechanisms.To address the notoriously significant volume changes accompanying intercalation or formation of alloy/compounds,we aim to introduce and utilize a weak,reversible Fe-N interaction during the(de)intercalation of ammonium ions(NH_(4)^(+))within iron(Ⅲ)hexacyanoferrate(FeHCF),inspired by manipulating the electrostatic adsorption between N and Fe in the early stages of ammonia synthesis(Bosch-Harber Process,Chemical Engineering)and steel nitriding processes(Metal Industry).Such strategy of switching well-balanced Fe-N interaction is confirmed in between the nitrogen of ammonium ions and highspin Fe in FeHCF,as observed by using X-ray absorption spectroscopy.The resulting material provided an extremely stable energy storage(58 mAh g^(-1) after 10000 cycles at current density of 1 A g^(-1))as well as high-rate performance(23.6 mAh g^(-1) at current density of 10 A g^(-1)).展开更多
基金the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University,through the Research Funding Program(#RFP-1440-3)。
文摘The availability of chemical and biological data presented in this paper is the basis for understanding not only the current state of anti-cancer drugs based on gold(Ⅲ),but also the rationale for strategies for future drug design.New Au(Ⅲ)nanosized complexes of cefotaxime(ceph-3)and cefepime(ceph-4)ligands as a 3rd and 4th of cephalosporin generation drugs were synthesized.Gold(Ⅲ)complexes were discussed based on the elemental,molar conductance,thermal and magnetic moment measurements as well as spectral(FTIR,1HNMR,UV-Vis,and XRD)techniques.FT-IR spectra revealed that the ceph-3 and ceph-4 ligands reacted as a bidentate ligands through carboxylate oxygen andβ-lactam oxygen groups.The analytical analysis confirm that the molar ratio is 1∶1(Au 3+/ceph)with general formula[Au(L)(Cl)2]where L=ceph-3 or ceph-4.The structures of Au(Ⅲ)complexes were presence as a square planar geometry.X-ray diffraction patterns referred to a crystalline nature for all synthesized complexes.TEM analyses confirmed that the synthetic gold(Ⅲ)complexes have a nanosized particles.In vitro antimicrobial activities of Au(Ⅲ)complexes were evaluated towards two types of bacteria(G+&G-).The antitumor activities of gold(Ⅲ)complexes are appraised against breast(MCF-7)and colorectal adenocarcinoma(Caco-2)cell lines,which means that the two complexes may consider promising anticancer drugs.
基金Projects(81373284,81102344) supported by the National Natural Science Foundation of China
文摘The spherical macroporous cellulose(SMC) was fabricated using medical absorbent cotton as raw material and nano CaCO3 as porogenic agents.And then,the phenylglycine was grafted onto the SMC to obtain the novel spherical macroporous cellulose derivative adsorbent(PSMC).FT-IR and scanning electron microscope(SEM) were employed to characterize the adsorbents and Fe3+ ions served as model solute to evaluate the adsorption property of the adsorbents.The experimental results show that the amount of porogenic agents and the value of pH have obvious influence on adsorption capacity of the adsorbents.The data of adsorption kinetic and isotherm display that the adsorbents possess excellent equilibrium adsorption capacity(348.94 mg/g) and have a bright prospect and considerable potential in the treatment of Fe3+ ions in wastewater.
基金Supported by the Ministerio De Ciencia Y Technologia(NoSB2004-oobo)
文摘A variety of gold(Ⅲ) adducts having a-ligated oxygen-donor ligands have been prepared from [Au(ppy)Cl2](ppy.phenylpyridine)(1) either by partial or total replacement of the chloride ions. The new species comprise hydroxo-[Au(ppy)(OH)Cl](2), and [Au(ppy)(OH)2](3), oxo-[Au2(ppy)2(μ-O)2](4), acetate-[Au(ppy)(O2CMe2)] (5), and alkoxo complexes-[Au(ppy)(OR)Cl](6, 7) and [Au(ppy)(OR)2](8--10)(R=Me, 6 and 8; Et, 7 and 9; Pr, 10). The dihydroxo and the oxo complexes can be interconverted by refluxing the former in anhydrous THF and the latter in water. The hydroxides 2 and 3 and the acetato complex 5 undergo σ-ligand metathesis in ROH solution(R=Me, Et or Pr) to give the corresponding alkoxides.
文摘The electrooxidation of hydrogen on platinum and gold electrodes is comparatively described in this paper. The reaction is faster on platinum than on the gold surface, because the reactive diffuses inside of the gold metal. This process is complicated with the lift of surface reconstruction of the (100) plane, which allows the fast penetration of the H atoms through the more open surface. The diffusion limiting current is then discontinued and the current falls. On platinum, the current fall occurs simultaneously with the metal oxide formation. It is assumed that the hydrogen helps the adsorbed OH group formation, which is the first step of metal oxidation, and it has been called “incipient hydrous oxide” (IHO). Current begins to fall slowly at the (IHO) potential. At higher potential the current falls abruptly.
基金supported by the National Natural Science Foundation of China(No.50608056)the Hong Kong Research Grants(No.HKUST6106/03E)the Program for Young Excellent Talents in Tongji University in part(No.2006KJ033).
文摘Humic substances are ubiquitous redox-active organic compounds of environment. In this study, experiments were conducted to determine the reduction capacity of humic acid in the man-ix of bromate and Fe(Ⅲ) solutions and the role of Fe(Ⅲ) in this redox process. The results showed that the humic acid regenerated Fe(Ⅱ) and reduced bromate abiotically. The addition of Fe(Ⅲ) could accelerate the bromate reduction rate by forming humic acid-Fe(Ⅲ) complexes. Iron species acts as electron mediator and catalyst for the bromate reduction by humic acid, in which humic acid transfers electrons to the complexed Fe(Ⅲ) to form Fe(Ⅱ), and the regenerated Fe(Ⅱ) donate the electrons to bromate. The kinetics study on bromate reduction further indicated that bromate reduction by humic acid-Fe(Ⅲ) complexes is pH dependent. The rate decreased by 2-fold with the increase in solution pH by one unit. The reduction capacity of Aldrich humic acid was observed to be lower than that of humic acid or natural organic matter of Suwanne River, indicating that such redox process is expected to occur in the environment.
基金This study is financially supported by the National Natural Science Foundation of China (No. 60508012)the Natural Sci-ence Foundation of Zhejiang Province (No. Y106725)+1 种基金the Natural Science Foundation of Ningbo (No. 2006A610048)the Scientific and Technological Project Funding of Zhejiang Province (No. 2006C31040).
文摘A DNA biosensor with [Ru(DA-bpy)3]Cl2(DA-bpy:4,4'-diamino-2,2'-bipyridine) (RuL) as the electrochemical probe was prepared on pyrolytic graphite electrode (PGE) through the supramolecular interaction between RuL complex and DNA template. Cyclic voltammetry of RuL-DNA film showed a pair of stable and reversible peaks corresponding to the Ru(Ⅲ)/Ru(Ⅲ) redox potential of-0.165 V versus AglAgCl in pa 7.4 0.1 mol·L^-1Tris-HCl. The electron transfer was expected across the double-strand DNA by an "electron tunneling" mechanism. When the DNA biosensor was immerged in gold (Ⅲ) buffer solution, the current peak signal (I) of the RuL-DNA supramolecular depressed and △I was linear in the concentration range of Au ion from 1×10^-7 to 2×10^-5 mol·L^-1 with a regression coefficient of 0.9879. The detection limit was 5×10^-8 mol·L^-1. The developed procedures were applied to the analysis of synthetic samples of real materials with good sensitivity and selectivity.
文摘The new catalytic kinetic spectrophotometric method for Au(III) determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of sudan red III by ammonium peroxodisulfate ((NH4)2S2O8) with nitrilo triacetic acid as an activator in microemulsion and H2SO4 medium. Under optimum conditions, there was the linearity of the calibration curve in the concentration range from 0 to 20 μg/L Au(Ⅲ) at 520 nm. The relative standard deviation was 3.0% with a correlation coefficient of 0.9986. The detection limit achieved was 9.75 × 10^-5 μg/mL. A new method using a column packed with sulfhydryl dextrose gel (SDG) as a solid-phase extractant has been developed for the preconcentration and separation of Au(Ⅲ) ions. The method has been applied to the determination of trace gold with satisfactory results.
基金Supported by the Doctoral Foundation of Education Department of Hebei Province(NoB2004205) Hebei University Re-search Foundation(No2003Z09)
文摘In this study, the kinetics and mechanism of the iridium( Ⅲ ) -catalyzed oxidation of ethanol amine(EAN) by cerium(Ⅳ) in a sulfuric acid medium was investigated using titrimetric technique of redox in a temperature range of 298--313 K. It was found that the reaction is of first order with respect to Ce( Ⅳ ) and It( Ⅲ ), and a positive fractional order with respect to EAN. It was also found that the pseudo-first-order ( [EAN ] 〉〉 [ Ce ( Ⅳ) ] ) rate constant koba decreases with the increase of [ H^+ ] and [ HSO^-4 ]. Under the protection of nitrogen gas, the reaction system can initiate the polymerization of acrylonitrile, indicating the generation of free radicals. On the basis of the experimental results, a suitable mechanism was proposed. From the dependence of koba on the concentration of hydrogen sulfate, Ce(SO4)2 was found to be the kinetically active species. The rate constants of the rote-determining step together with the activation parameters were evaluated.
基金Project(2007AA060902) supported by the National High Technology Research and Development Program of ChinaProject(2010CB630905) supported by the National Basic Research Program of China
文摘The bacterial pre-oxidation process of arsenic-containing gold concentrates and the bacterial activity under different chloride ion concentrations were studied by using a mixture of thermophilic strains TCJ domesticated in production.The experimental result shows that with different samples and leaching systems,the adaptability and Cl- tolerance of bacteria are different,and that appropriate chloride ion concentration is conductive to bacterial oxidation,while higher chloride ion concentration will inhibit the bacterial activity and affect the pre-oxidation performance.Under the present production conditions,TCJ can adapt to the changes of water quality in the source of water and its critical chloride ion tolerance value is 2.7 g/L.
文摘The mechanism of adsorbing indium(Ⅲ) from sulfate solutions with CL-P204Levextrel resin containing di(-2-ethylhexyl) phosphoric acid was examined by batch operation andinfrared spectra. The results showed that the P204 adsorbed on the resin behaved in the similar wayto solvent extraction except that it was as a monomer in resin adsorbing but in dimeric form insolvent extraction. Three factors including temperature, indium(Ⅲ) concentration of solution, andthe size of resin particles which influence the In^(3+)/H^+ exchange on CL-P204 Levextrel resin wereinvestigated by the modified limited batch technique in order to determine the kinetics ofIn^(3+)/H^+ exchange. It was found that the rate of ion exchange increased with the temperature andthe concentration of solution increasing and with the size of the resin particles decreasing.According to the expression developed by Boyd et al., the controlling factor of In^(3+)/H^+ exchangeon CL-P204 Levextrel resin was the diffusion through the resin particles. The effective diffusioncoefficient, activation energy, and entropy of activation in the particle-diffusion were determinedas 1.57 x 10^(-10) m^2/s, 11.9 kJ/mol, -84.1 J/(mol·K), respectively.
文摘Electroreduction of Co(Ⅱ)to metallic cohalt in urea melt is irrevsible in one step.The transfer coeffi-cient of electrode reaction of Co(Ⅱ)+2e=Co(O)and the diffusion coefficient of Co(Ⅱ)were determined.The lanthanum can be inductively codeposited with cobalt. The contents of lanthanum in cobalt-lanthanum de-posts increase with the shift of electrode potential to the negative direction and the raise of La(Ⅲ)/Co(Ⅱ)mo-lar ratio in the melt. The cyclic voltammetry,open circuit potential-time curve after potentiostatic electrolysisand electron probe analyas were used.
文摘The adsorption characteristics of rare earth ion La(Ⅲ) on Yunnan bowl tea surface from aqueous solution and effects of various surfactants on the adsorption were studied. It was found that Yunnan bowl tea can adsorb strongly La(Ⅲ) and pH may affect drastically the adsorption amount of La(Ⅲ). The adsorption law of La(Ⅲ) on Yunnan bowl tea surface follows the Langmuir equation. The maximum adsorption amount of La(Ⅲ) can reach 15 mg·g (-1). A comprehensive adsorption model is suggested according to the experimental results.
基金Supported by the Natural Science Foundation of Yunnan Province,China(No.2000E0008Z).
文摘A rapid synthesis of size-controlled gold nanoparticles was proposed.The method is based on the sensitive intramolecular photoreduction reaction of Fe(Ⅲ)-EDTA complex in chloroacetic acid-sodium acetate buffer solution,where Fe(Ⅱ)-EDTA complex generated by photo-promotion acts as a reductant of AuCl-4 ions.Gold nanoparticles formed were stabilized by EDTA ligand or other protective agents added.As a result,well-dispersed gold nanoparticles with an average diameter range of 6.7 to 50.9 nm were obtained.According to the characterizations by the UV spectrum and TEM,the intramolecular charge transfer of the excited states of complex Fe(Ⅲ)-EDTA and the mechanism of forming gold nanoparticles were discussed in detail.
基金This work was financially supported by the National Science Foundation of China(No.20376085).
文摘The adsorption of Fe(Ⅲ)ions from aqueous solution by chitosan alpha-ketoglutaric acid(KCTS)and hydroxamated chitosan alpha-ketoglutaric acid(HKCTS)was studied in a batch adsorption system.Experiments were carried out as function of pH,temperature,agitation rate and concentration of Fe(Ⅲ)ions.The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and isotherm constants were determined.The Langmuir model agrees very well with experimental data.The pseudo-first-order a...
基金supported by the National Natural Science Foundation of China(51932003,51872115)2020 International Cooperation Project of the Department of Science and Technology of Jilin Province(20200801001GH)+2 种基金Project for Selfinnovation Capability Construction of Jilin Province Development and Reform Commission(2021C026)the Project supported by State Key Laboratory of Luminescence and Applications(KLA-2020-05)the Fundamental Research Funds for the Central Universities JLU,and“Double-First Class”Discipline for Materials Science&Engineering.
文摘The interaction between electrode materials and charge carriers is one of the central issues dominating underlying energy storage mechanisms.To address the notoriously significant volume changes accompanying intercalation or formation of alloy/compounds,we aim to introduce and utilize a weak,reversible Fe-N interaction during the(de)intercalation of ammonium ions(NH_(4)^(+))within iron(Ⅲ)hexacyanoferrate(FeHCF),inspired by manipulating the electrostatic adsorption between N and Fe in the early stages of ammonia synthesis(Bosch-Harber Process,Chemical Engineering)and steel nitriding processes(Metal Industry).Such strategy of switching well-balanced Fe-N interaction is confirmed in between the nitrogen of ammonium ions and highspin Fe in FeHCF,as observed by using X-ray absorption spectroscopy.The resulting material provided an extremely stable energy storage(58 mAh g^(-1) after 10000 cycles at current density of 1 A g^(-1))as well as high-rate performance(23.6 mAh g^(-1) at current density of 10 A g^(-1)).