Environmentally persistent and bioaccumulative perfluorooctanic acid （PFOA） was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe（Ⅲ）, 80% of PFOA with i...Environmentally persistent and bioaccumulative perfluorooctanic acid （PFOA） was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe（Ⅲ）, 80% of PFOA with initial concentration of 48μmol/L （20 mg/L） was effectively degraded and 47.8% of fluorine atoms in PFOA molecule were transformed into inorganic fluoride ion after 4 h reaction. Shorter chain perfluorocarboxylic acids bearing C3-C7 and fluoride ion were detected and identified by LC/MS and IC as the degradation products in the aqueous solution. It was proposed that complexes of PFOA with Fe（Ⅲ） initiated degradation of PFOA irradiated with 254 nm UV light.展开更多
A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At ...A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.展开更多
Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrha...Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrhagic area.However,the regulato ry mechanism of histone deacetylases in central post-stroke pain remains unclea r.Here,we show that iron overload leads to an increase in histone deacetylase 2expression in damaged ventral posterolateral nucleus neurons.Inhibiting this increase restored histone H3 acetylation in the Kcna2 promoter region of the voltage-dependent potassium(Kv)channel subunit gene in a rat model of central post-stroke pain,thereby increasing Kcna2expression and relieving central pain.However,in the absence of nerve injury,increasing histone deacetylase 2 expression decreased Kcna2expression,decreased Kv current,increased the excitability of neurons in the ventral posterolateral nucleus area,and led to neuropathic pain symptoms.Moreover,treatment with the iron chelator deferiprone effectively reduced iron overload in the ventral posterolateral nucleus after intracerebral hemorrhage,reversed histone deacetylase 2 upregulation and Kv1.2 downregulation,and alleviated mechanical hypersensitivity in central post-stroke pain rats.These results suggest that histone deacetylase 2 upregulation and Kv1.2 downregulation,mediated by iron overload,are important factors in central post-stroke pain pathogenesis and co uld se rve as new to rgets for central poststroke pain treatment.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 structure of the title complex [Fe2（μ-O）（bpb）2]n （bpb 2=1,2-bis（pyridine-2carboxamido） benzenate） has been characterized by single-crystal X-ray diffraction analysis.The complex （C36 H24 Fe2N8O5,Mr=760.3...The structure of the title complex [Fe2（μ-O）（bpb）2]n （bpb 2=1,2-bis（pyridine-2carboxamido） benzenate） has been characterized by single-crystal X-ray diffraction analysis.The complex （C36 H24 Fe2N8O5,Mr=760.33） crystallizes in the monoclinic space group P2 1/c with a=8.4615（17）,b=33.704（7）,c=11.173（2）,β=91.12（3）o,V=3185.7（11）3,Z=4,D c=1.585 g/cm 3,μ（MoK）=0.970 mm-1,F（000）=1552,R int=0.0381,the final R=0.0454 and wR=0.1114.The magnetic susceptibilities of the complex have been examined in the temperature range of 2-300 K.The magnetic data were fitted to give the parameters of J d=-77.7（9） and J c=-11.5（6） cm-1.展开更多
Iron(Ⅲ) loaded novolac-based network adsorbents 1 and 2 were studied for efficient removal of azo-dye pollutants from aqueous solutions. The adsorption behavior was evaluated by using methyl orange and orange-G as mo...Iron(Ⅲ) loaded novolac-based network adsorbents 1 and 2 were studied for efficient removal of azo-dye pollutants from aqueous solutions. The adsorption behavior was evaluated by using methyl orange and orange-G as model azo dyes. The effect of parameters such as contact time and initial dye concentration on the adsorption of azo dyes was studied. The results showed that loading of Fe(Ⅲ) onto the sorbent networks has noticeable effect on azo-dye sorption capacity. The adsorption equilibrium data were fitted to Freundlich isotherm model. Besides, the reusability of the dye loaded sorbents was investigated on adjusting pH of solutions.展开更多
Tris（d,d-dicampholylmethanato） iron （Ⅲ） complex, Fe（dcm）3, was found to be an excellent catalyst for asymmetric oxygenation of styrene analogues into the corresponding epoxides. Good chemical yields and higher ...Tris（d,d-dicampholylmethanato） iron （Ⅲ） complex, Fe（dcm）3, was found to be an excellent catalyst for asymmetric oxygenation of styrene analogues into the corresponding epoxides. Good chemical yields and higher enantioselectivity were obtained with combined use of molecular oxygen and an aldehyde at 30℃, Some factors influencing enantioselectivity were discussed.展开更多
Organic?inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol?gel method, and the structure of the coating was confirmed ...Organic?inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol?gel method, and the structure of the coating was confirmed by FT-IR. The results of the characterization show that the corrosion resistance of the coating with 1.5 mmol/L cerium ion (III) gains significant improvement, in which the colour retention time of CuSO4 extends to 500 s, the anti-acid and alkali corrosion rates reduce by 67% and 70% compared with the blank one, respectively, and the salt spray tests also show good corrosion resistance. The electrochemical tests demonstrate that the self-corrosion current density and potential of the sample with hybrid coating are about 2.877×10?7 A/cm2 and?0.550 V, respectively. The metallographic and SEM images show that the hybrid coating is uniform and dense, and the EDS analysis confirms that the coating is mainly composed of Al, Si and Ce elements.展开更多
The adsorption behavior and mechanism of Bi（Ⅲ） ions on the rutile-water interface were investigated through micro-flotation, Zeta potential measurement, adsorption amount measurement and X-ray photoelectron spectro...The adsorption behavior and mechanism of Bi（Ⅲ） ions on the rutile-water interface were investigated through micro-flotation, Zeta potential measurement, adsorption amount measurement and X-ray photoelectron spectroscopy（XPS）. According to the results of micro-flotation, Bi（Ⅲ） ions could largely improve the rutile flotation recovery（from 62% to 91%）, and they could increase the activating sites and reduce the competitive adsorption between nonyl hydroxamic acid negative ions and OH-ions, which determined that Bi（Ⅲ） ions were capable of activating rutile flotation. The adsorption of Bi（Ⅲ） ions onto the rutile surface led to the shift of Zeta potential into the positive direction, which was good for the adsorption of nonyl hydroxamic acid anions. In addition, the results of XPS indicated that the chemical environment around Ti atom had not changed before and after the adsorption of Bi（Ⅲ） ions. Based on the adsorption mechanism of Bi（Ⅲ） ions, it was deduced that firstly Bi（Ⅲ） ions occupied the vacancies of the original Ca^2＋, Mg^2＋ and Fe^2＋ ions on the rutile surface; secondly Bi（Ⅲ） ions covered on the rutile surface in the form of hydroxides.展开更多
To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe(Ⅲ) and H 2O 2 in the absenc...To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe(Ⅲ) and H 2O 2 in the absence of light instead of Fe(Ⅱ) and H 2O 2 was studied. Results showed that use of Fe (Ⅲ) is more promising than Fe(Ⅱ). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount of salicylic acid is added which is a one of the priority pollutant.展开更多
The coordination nature of a number of substituted sodiumphenoxides to iron （Ⅲ） ion has been studied. The o-nitrosodiumphenoxide was found to have different coordination behaviour from that the sodium salts of sali...The coordination nature of a number of substituted sodiumphenoxides to iron （Ⅲ） ion has been studied. The o-nitrosodiumphenoxide was found to have different coordination behaviour from that the sodium salts of salicylic acid and methylsalicylate showed. The structure of the complexes, the number of the ligands being coordinated to the metal ion, has also been determined by titration, uv-vis spectroscopy, atomic absorption and the flame test. In addition, other sodium phenoxides were also involved in this study for comparison. An electric conductivity study on the resulting complexes was carried out and all complexes were found to be semiconductors.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
Processing conditions of effectively separating indium from the leaching solution of a smelting antimony slag were studied. For the leaching solution containing indium and antimony and iron ions, indium was separated ...Processing conditions of effectively separating indium from the leaching solution of a smelting antimony slag were studied. For the leaching solution containing indium and antimony and iron ions, indium was separated by extracting with HDEHP kerosine solution, washing antimony and iron ions with oxalic acid solution and stripping indium with a dilute solution of hydrochloric acid. InCl 3 solution with purity above 90% is obtained. Indium can be enriched through a circulation of stripping with a dilute HCl solution. The concentration of InCl 3 solution is about 25～30 g/L.展开更多
The present study dealt with the mechanism of competitive adsorption of Sb(Ⅲ)and Fe(Ⅱ)ions from a copper-containing aqueous solution on Purolite S957,a commercially available cationic ion-exchange adsorbent.Experime...The present study dealt with the mechanism of competitive adsorption of Sb(Ⅲ)and Fe(Ⅱ)ions from a copper-containing aqueous solution on Purolite S957,a commercially available cationic ion-exchange adsorbent.Experiments were conducted using aqueous copper sulfate solutions containing either single or conjoint ions,using both sedentary and batch adsorption techniques to ascertain the sensitivity of the adsorption process to variation in p H,mass of resin,contact time,and temperature as well as establishing the optimal range of variables for maximum ion removal.The data from single ion adsorption tests were fitted by non-linear regression techniques to Henry,Langmuir,Freundlich,Temkin,and Dubinin–Radushkevich isotherm models.Freundlich isotherm for Sb(Ⅲ)and Freundlich and Henry models for Fe(Ⅱ)solutions best express the adsorption equilibrium data;while for binary ion electrolytes,the extended Freundlich model fitted the data satisfactorily.The kinetic model adequately describing adsorption was shown to be the pseudo-first-order,underscoring the dominant role of physical adsorption playing in the process.Thermodynamic parameters for the adsorption process reveal differences in the Sb(Ⅲ)adsorption mechanism from single ion and Sb(Ⅲ)-Fe(Ⅱ)containing electrolytes.The adsorption of Sb(Ⅲ)alone is endothermic,whereas the process becomes exothermic in the Sb(Ⅲ)-Fe(Ⅱ)system.展开更多
Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ...Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.展开更多
The low efficiency of oxygen evolution reaction(OER) is regarded as one of the major roadblocks for metal-air batteries and water electrolysis.Herein,a high-performance OER catalyst of NiFe_(0.2)(oxy)hydroxide(NiFe_(0...The low efficiency of oxygen evolution reaction(OER) is regarded as one of the major roadblocks for metal-air batteries and water electrolysis.Herein,a high-performance OER catalyst of NiFe_(0.2)(oxy)hydroxide(NiFe_(0.2)-O_(x)H_(y)) was developed through topotactic transformation of a Prussian blue analogue in an alkaline solution,which exhibits a low overpotential of only 263 mV to reach a current density of 10 mA cm^(-2) and a small Tafel slope of 35 mV dec-1.Ex-situ/operando Raman spectroscopy results indicated that the phase structure of NiFe_(0.2)-O_(x)H_(y) was irreversibly transformed from the type of α-Ni(OH)_(2) to γ-NiOOH with applying an anodic potential,while ex-situ/operando 57Fe Mossbauer spectroscopic studies evidenced the in-situ production of abundant high-valent iron species under OER conditions,which effectively promoted the OER catalysis.Our work elucidates that the amount of high-valent iron species in-situ produced in the NiFe(oxy)hydroxide has a positive correlation with its water oxidation reaction performance,which further deepens the understanding of the mechanism of NiFe-based electrocatalysts.展开更多
文摘Environmentally persistent and bioaccumulative perfluorooctanic acid （PFOA） was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe（Ⅲ）, 80% of PFOA with initial concentration of 48μmol/L （20 mg/L） was effectively degraded and 47.8% of fluorine atoms in PFOA molecule were transformed into inorganic fluoride ion after 4 h reaction. Shorter chain perfluorocarboxylic acids bearing C3-C7 and fluoride ion were detected and identified by LC/MS and IC as the degradation products in the aqueous solution. It was proposed that complexes of PFOA with Fe（Ⅲ） initiated degradation of PFOA irradiated with 254 nm UV light.
文摘A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.
基金supported by the National Natural Science Foundation of China,Nos.U2004106 (to WY),81971061 (to JC)the Key Scientific Research Project of Colleges and Universities in Henan Province,No.21A320039 (to WY)。
文摘Thalamic hemorrhage can lead to the development of central post-stroke pain.Changes in histone acetylation levels,which are regulated by histone deacetylases,affect the excitability of neurons surrounding the hemorrhagic area.However,the regulato ry mechanism of histone deacetylases in central post-stroke pain remains unclea r.Here,we show that iron overload leads to an increase in histone deacetylase 2expression in damaged ventral posterolateral nucleus neurons.Inhibiting this increase restored histone H3 acetylation in the Kcna2 promoter region of the voltage-dependent potassium(Kv)channel subunit gene in a rat model of central post-stroke pain,thereby increasing Kcna2expression and relieving central pain.However,in the absence of nerve injury,increasing histone deacetylase 2 expression decreased Kcna2expression,decreased Kv current,increased the excitability of neurons in the ventral posterolateral nucleus area,and led to neuropathic pain symptoms.Moreover,treatment with the iron chelator deferiprone effectively reduced iron overload in the ventral posterolateral nucleus after intracerebral hemorrhage,reversed histone deacetylase 2 upregulation and Kv1.2 downregulation,and alleviated mechanical hypersensitivity in central post-stroke pain rats.These results suggest that histone deacetylase 2 upregulation and Kv1.2 downregulation,mediated by iron overload,are important factors in central post-stroke pain pathogenesis and co uld se rve as new to rgets for central poststroke pain treatment.
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 Natural Science Foundation of China (No. 2117624)the Fundamental Research Funds for the Central Universities (China University of Mining and Technology)
文摘The structure of the title complex [Fe2（μ-O）（bpb）2]n （bpb 2=1,2-bis（pyridine-2carboxamido） benzenate） has been characterized by single-crystal X-ray diffraction analysis.The complex （C36 H24 Fe2N8O5,Mr=760.33） crystallizes in the monoclinic space group P2 1/c with a=8.4615（17）,b=33.704（7）,c=11.173（2）,β=91.12（3）o,V=3185.7（11）3,Z=4,D c=1.585 g/cm 3,μ（MoK）=0.970 mm-1,F（000）=1552,R int=0.0381,the final R=0.0454 and wR=0.1114.The magnetic susceptibilities of the complex have been examined in the temperature range of 2-300 K.The magnetic data were fitted to give the parameters of J d=-77.7（9） and J c=-11.5（6） cm-1.
文摘Iron(Ⅲ) loaded novolac-based network adsorbents 1 and 2 were studied for efficient removal of azo-dye pollutants from aqueous solutions. The adsorption behavior was evaluated by using methyl orange and orange-G as model azo dyes. The effect of parameters such as contact time and initial dye concentration on the adsorption of azo dyes was studied. The results showed that loading of Fe(Ⅲ) onto the sorbent networks has noticeable effect on azo-dye sorption capacity. The adsorption equilibrium data were fitted to Freundlich isotherm model. Besides, the reusability of the dye loaded sorbents was investigated on adjusting pH of solutions.
文摘Tris（d,d-dicampholylmethanato） iron （Ⅲ） complex, Fe（dcm）3, was found to be an excellent catalyst for asymmetric oxygenation of styrene analogues into the corresponding epoxides. Good chemical yields and higher enantioselectivity were obtained with combined use of molecular oxygen and an aldehyde at 30℃, Some factors influencing enantioselectivity were discussed.
基金Project(51404038)supported by the National Natural Science Foundation of China
文摘Organic?inorganic hybrid coating on the surface of aluminum-tube used in refrigeration equipment using cerium ion (III) as the additive was fabricated by sol?gel method, and the structure of the coating was confirmed by FT-IR. The results of the characterization show that the corrosion resistance of the coating with 1.5 mmol/L cerium ion (III) gains significant improvement, in which the colour retention time of CuSO4 extends to 500 s, the anti-acid and alkali corrosion rates reduce by 67% and 70% compared with the blank one, respectively, and the salt spray tests also show good corrosion resistance. The electrochemical tests demonstrate that the self-corrosion current density and potential of the sample with hybrid coating are about 2.877×10?7 A/cm2 and?0.550 V, respectively. The metallographic and SEM images show that the hybrid coating is uniform and dense, and the EDS analysis confirms that the coating is mainly composed of Al, Si and Ce elements.
基金Project(51474254)supported by the National Natural Science Foundation of ChinaProject(2013M531813)supported by the China Postdoctoral Science Foundation+1 种基金Project(2016zzts111)supported by the Independent Exploration and Innovation Program of Central South University,ChinaProject(CSUZC201715)supported by Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘The adsorption behavior and mechanism of Bi（Ⅲ） ions on the rutile-water interface were investigated through micro-flotation, Zeta potential measurement, adsorption amount measurement and X-ray photoelectron spectroscopy（XPS）. According to the results of micro-flotation, Bi（Ⅲ） ions could largely improve the rutile flotation recovery（from 62% to 91%）, and they could increase the activating sites and reduce the competitive adsorption between nonyl hydroxamic acid negative ions and OH-ions, which determined that Bi（Ⅲ） ions were capable of activating rutile flotation. The adsorption of Bi（Ⅲ） ions onto the rutile surface led to the shift of Zeta potential into the positive direction, which was good for the adsorption of nonyl hydroxamic acid anions. In addition, the results of XPS indicated that the chemical environment around Ti atom had not changed before and after the adsorption of Bi（Ⅲ） ions. Based on the adsorption mechanism of Bi（Ⅲ） ions, it was deduced that firstly Bi（Ⅲ） ions occupied the vacancies of the original Ca^2＋, Mg^2＋ and Fe^2＋ ions on the rutile surface; secondly Bi（Ⅲ） ions covered on the rutile surface in the form of hydroxides.
文摘To develop more efficient chemical methods for the demineralization of organic pollutants from water bodies, which one was also mimic to the nature, a degradation of methylene blue by Fe(Ⅲ) and H 2O 2 in the absence of light instead of Fe(Ⅱ) and H 2O 2 was studied. Results showed that use of Fe (Ⅲ) is more promising than Fe(Ⅱ). The present study reflects that Fenton reaction is more efficient, in the presence of a small amount of salicylic acid is added which is a one of the priority pollutant.
文摘The coordination nature of a number of substituted sodiumphenoxides to iron （Ⅲ） ion has been studied. The o-nitrosodiumphenoxide was found to have different coordination behaviour from that the sodium salts of salicylic acid and methylsalicylate showed. The structure of the complexes, the number of the ligands being coordinated to the metal ion, has also been determined by titration, uv-vis spectroscopy, atomic absorption and the flame test. In addition, other sodium phenoxides were also involved in this study for comparison. An electric conductivity study on the resulting complexes was carried out and all complexes were found to be semiconductors.
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.
文摘Processing conditions of effectively separating indium from the leaching solution of a smelting antimony slag were studied. For the leaching solution containing indium and antimony and iron ions, indium was separated by extracting with HDEHP kerosine solution, washing antimony and iron ions with oxalic acid solution and stripping indium with a dilute solution of hydrochloric acid. InCl 3 solution with purity above 90% is obtained. Indium can be enriched through a circulation of stripping with a dilute HCl solution. The concentration of InCl 3 solution is about 25～30 g/L.
文摘The present study dealt with the mechanism of competitive adsorption of Sb(Ⅲ)and Fe(Ⅱ)ions from a copper-containing aqueous solution on Purolite S957,a commercially available cationic ion-exchange adsorbent.Experiments were conducted using aqueous copper sulfate solutions containing either single or conjoint ions,using both sedentary and batch adsorption techniques to ascertain the sensitivity of the adsorption process to variation in p H,mass of resin,contact time,and temperature as well as establishing the optimal range of variables for maximum ion removal.The data from single ion adsorption tests were fitted by non-linear regression techniques to Henry,Langmuir,Freundlich,Temkin,and Dubinin–Radushkevich isotherm models.Freundlich isotherm for Sb(Ⅲ)and Freundlich and Henry models for Fe(Ⅱ)solutions best express the adsorption equilibrium data;while for binary ion electrolytes,the extended Freundlich model fitted the data satisfactorily.The kinetic model adequately describing adsorption was shown to be the pseudo-first-order,underscoring the dominant role of physical adsorption playing in the process.Thermodynamic parameters for the adsorption process reveal differences in the Sb(Ⅲ)adsorption mechanism from single ion and Sb(Ⅲ)-Fe(Ⅱ)containing electrolytes.The adsorption of Sb(Ⅲ)alone is endothermic,whereas the process becomes exothermic in the Sb(Ⅲ)-Fe(Ⅱ)system.
文摘Sulphur-containing aromatic amines were prepared efficiently in good to excellent yields by reduction of the corresponding sulphur-containing aromatic nitro compounds with hydrazine hydrate in the presence of iron（Ⅲ） oxide-MgO catalyst. The catalyst exhibited high activity and stability for the reduction of sulphur-containing aromatic nitro compounds. The yields of sulphur-containing aromatic amines were up to 91-99 % at 355 K after reduction for 1-4 h over this catalyst.
基金financially supported by the National Natural Science Foundation of China(21476232,21961142006)the International Partnership Program of Chinese Academy of Sciences(121421KYSB20170020)the State Key Laboratory of Catalysis in Dalian Institute of Chemical Physics(N-16-07)。
文摘The low efficiency of oxygen evolution reaction(OER) is regarded as one of the major roadblocks for metal-air batteries and water electrolysis.Herein,a high-performance OER catalyst of NiFe_(0.2)(oxy)hydroxide(NiFe_(0.2)-O_(x)H_(y)) was developed through topotactic transformation of a Prussian blue analogue in an alkaline solution,which exhibits a low overpotential of only 263 mV to reach a current density of 10 mA cm^(-2) and a small Tafel slope of 35 mV dec-1.Ex-situ/operando Raman spectroscopy results indicated that the phase structure of NiFe_(0.2)-O_(x)H_(y) was irreversibly transformed from the type of α-Ni(OH)_(2) to γ-NiOOH with applying an anodic potential,while ex-situ/operando 57Fe Mossbauer spectroscopic studies evidenced the in-situ production of abundant high-valent iron species under OER conditions,which effectively promoted the OER catalysis.Our work elucidates that the amount of high-valent iron species in-situ produced in the NiFe(oxy)hydroxide has a positive correlation with its water oxidation reaction performance,which further deepens the understanding of the mechanism of NiFe-based electrocatalysts.
