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2016 Volume 33 Issue 11
2016, 33(11): 1221-1233
doi: 10.11944/j.issn.1000-0518.2016.11.160337
Abstract:
The rise of emerging contaminants and microorganisms causes the complexity of drinking water quality and brings a gap between peoples demand and water treatment efficiency using conventional treatment reagents and techniques. Ferrate is an effective and multi-functional green water purification material, which shows both good oxidation and coagulation ability without secondary pollution. This paper reviews the removal mechanism of contaminants including heavy metal ions, emerging contaminants and microorganisms by ferrate. At present, the investigation of ferrates oxidation and coagulation cooperative effect is insufficient and the application of ferrates in water treatment has not been fully developed. Therefore, the oxidation and coagulation cooperative effect of ferrates is emphatically discussed to direct the application of ferrates in water treatment. Finally, the prospect of application of ferrates in water treatment is commented.
The rise of emerging contaminants and microorganisms causes the complexity of drinking water quality and brings a gap between peoples demand and water treatment efficiency using conventional treatment reagents and techniques. Ferrate is an effective and multi-functional green water purification material, which shows both good oxidation and coagulation ability without secondary pollution. This paper reviews the removal mechanism of contaminants including heavy metal ions, emerging contaminants and microorganisms by ferrate. At present, the investigation of ferrates oxidation and coagulation cooperative effect is insufficient and the application of ferrates in water treatment has not been fully developed. Therefore, the oxidation and coagulation cooperative effect of ferrates is emphatically discussed to direct the application of ferrates in water treatment. Finally, the prospect of application of ferrates in water treatment is commented.
2016, 33(11): 1234-1244
doi: 10.11944/j.issn.1000-0518.2016.11.160330
Abstract:
Supercapacitors, also known as electrochemical capacitors, is a green energy storage device. The reaserch of supercapacitors, fundamentally is seeking fully utilizable electrode materials with large specific surface area. As the sp2 hybridized carbon material primitive unit, graphene has a unique two-dimensional structure and excellent physical and chemical characters, and has great potential in the field of supercapacitors, in which research workers increasingly concern about graphene fiber supercapacitors. Based on the one-dimensional graphene fiber self-assembly and assembled together with prepared materials as the electrode material for supercapacitors, this review expounds the progress in controllable preparation, controllable build unique electrode materials with optimized performance for assembling of the high-performance supercapacitor. The development and prospect of related area are discussed.
Supercapacitors, also known as electrochemical capacitors, is a green energy storage device. The reaserch of supercapacitors, fundamentally is seeking fully utilizable electrode materials with large specific surface area. As the sp2 hybridized carbon material primitive unit, graphene has a unique two-dimensional structure and excellent physical and chemical characters, and has great potential in the field of supercapacitors, in which research workers increasingly concern about graphene fiber supercapacitors. Based on the one-dimensional graphene fiber self-assembly and assembled together with prepared materials as the electrode material for supercapacitors, this review expounds the progress in controllable preparation, controllable build unique electrode materials with optimized performance for assembling of the high-performance supercapacitor. The development and prospect of related area are discussed.
2016, 33(11): 1245-1252
doi: 10.11944/j.issn.1000-0518.2016.11.160327
Abstract:
Nanozymes, developed on the basis of nanomaterials, have promoted the development of chemistry, materials science and biology. Nanozymes have overcome many drawbacks of natural enzymes, such as high cost, easy loss of activity and rigid storage requirements. Currently, nanozymes have had great impact on biosensing, immunoassay and cancer diagnosis. This review article mainly focuses on the categories of nanozymes, the methods to tailor the activity of nanozymes and the research progress in the analytical application of nanozymes. Furthermore, a few thoughts and suggestions have been made to the future development direction of nanozymes.
Nanozymes, developed on the basis of nanomaterials, have promoted the development of chemistry, materials science and biology. Nanozymes have overcome many drawbacks of natural enzymes, such as high cost, easy loss of activity and rigid storage requirements. Currently, nanozymes have had great impact on biosensing, immunoassay and cancer diagnosis. This review article mainly focuses on the categories of nanozymes, the methods to tailor the activity of nanozymes and the research progress in the analytical application of nanozymes. Furthermore, a few thoughts and suggestions have been made to the future development direction of nanozymes.
2016, 33(11): 1253-1264
doi: 10.11944/j.issn.1000-0518.2016.11.160315
Abstract:
Protein microarray is capable of high-throughput monitoring biological toxins, analyzing the host-microbe interactions and the antigen-antibody interaction, and screening biomarkers of diseases. Therefore, protein microarray is expected to become one of the main technology of in vitro diagnostic and plays an important role in precision medicine of many diseases, such as pathogen infection, autoimmune diseases, neurodegenerative diseases, cancer and so on. Through analyzing the recently published research results, this review summarizes recent progress of protein microarray in the clinical analysis, analyzes the technical challenges in practical application, and discusses corresponding solutions.
Protein microarray is capable of high-throughput monitoring biological toxins, analyzing the host-microbe interactions and the antigen-antibody interaction, and screening biomarkers of diseases. Therefore, protein microarray is expected to become one of the main technology of in vitro diagnostic and plays an important role in precision medicine of many diseases, such as pathogen infection, autoimmune diseases, neurodegenerative diseases, cancer and so on. Through analyzing the recently published research results, this review summarizes recent progress of protein microarray in the clinical analysis, analyzes the technical challenges in practical application, and discusses corresponding solutions.
2016, 33(11): 1265-1273
doi: 10.11944/j.issn.1000-0518.2016.11.160017
Abstract:
Alkyl α-D-glucopyranosides were synthesized with D-glucose as the raw material by three reactions involving acetylation, SnCl4 catalyzing glycosylation with the aliphatic alcohols and deacetylation. The structures of alkyl α-D-glucopyranosides, their surface properties and thermotropic liquid crystalline properties were determined through NMR, surface tensiometer, polarization microscope and so on. The results show that alkyl α-D-glucopyranosides possess foaming and emulsifying power as their hydrophobic alkyl chain length n=6~9, wherein n-nonyl α-D-glucopyranoside has rather superior foaming and emulsifying power. The values of the surface tension(γCMC) and the critical micelle concentration(CMC) of the alkyl glycosides(n=6~9) are very low, their saturated adsorption capacity(Γmax) decreases with increasing alkyl chain length, and their saturation adsorption area(Amin) increases with the increase of alkyl chain lengths. The standard free energy of micellization(ΔGmic) and standard free energy of adsorption(ΔGads) for alkyl glycosides(n=6~9) are all less than zero, and the values of ΔGmic and ΔGads are more negative with the increase of the alkyl chain length. The n-octyl α-D-glucopyranoside has the best surface activity. Furthermore, the alkyl glucosides(n=4~9) does not have any skin irritation. Finally, all of alkyl α-D-glucopyranosides exhibit thermotropic liquid crystalline behavior, the temperature range of the thermotropic liquid crystalline phase becomes broader, and the stability of the thermotropic liquid crystalline phase becomes stronger with the increase of alkyl chain length.
Alkyl α-D-glucopyranosides were synthesized with D-glucose as the raw material by three reactions involving acetylation, SnCl4 catalyzing glycosylation with the aliphatic alcohols and deacetylation. The structures of alkyl α-D-glucopyranosides, their surface properties and thermotropic liquid crystalline properties were determined through NMR, surface tensiometer, polarization microscope and so on. The results show that alkyl α-D-glucopyranosides possess foaming and emulsifying power as their hydrophobic alkyl chain length n=6~9, wherein n-nonyl α-D-glucopyranoside has rather superior foaming and emulsifying power. The values of the surface tension(γCMC) and the critical micelle concentration(CMC) of the alkyl glycosides(n=6~9) are very low, their saturated adsorption capacity(Γmax) decreases with increasing alkyl chain length, and their saturation adsorption area(Amin) increases with the increase of alkyl chain lengths. The standard free energy of micellization(ΔGmic) and standard free energy of adsorption(ΔGads) for alkyl glycosides(n=6~9) are all less than zero, and the values of ΔGmic and ΔGads are more negative with the increase of the alkyl chain length. The n-octyl α-D-glucopyranoside has the best surface activity. Furthermore, the alkyl glucosides(n=4~9) does not have any skin irritation. Finally, all of alkyl α-D-glucopyranosides exhibit thermotropic liquid crystalline behavior, the temperature range of the thermotropic liquid crystalline phase becomes broader, and the stability of the thermotropic liquid crystalline phase becomes stronger with the increase of alkyl chain length.
2016, 33(11): 1274-1278
doi: 10.11944/j.issn.1000-0518.2016.11.160027
Abstract:
Cladribine, an anti-leukemia drug, was synthesized in 43.5% total yield by 4 steps. Readily available 6-chloropurine was glycosylated with 1-chloro-3,5-di-O-p-benzoyl-D-ribose with good selectivity for β anomer in the presence of NaH. The C2-H of β-glycosylated product was converted into C2-NO2 using 2,2,2-trifluoroacetic anhydride and tetrabutylammonium nitrate, followed by the transformation of C2-NO2 into C2-Cl in NH4Cl/EtOH solution. The deprotection step and ammonolysis of C6-Cl were accomplished in NH3/CH3OH. The separation of α-anomer, expensive starting materials and chromatography are not required. Moreover, cladribine could be produced on a 100 gram scale with maintained yield, indicating good potential in industrial applications.
Cladribine, an anti-leukemia drug, was synthesized in 43.5% total yield by 4 steps. Readily available 6-chloropurine was glycosylated with 1-chloro-3,5-di-O-p-benzoyl-D-ribose with good selectivity for β anomer in the presence of NaH. The C2-H of β-glycosylated product was converted into C2-NO2 using 2,2,2-trifluoroacetic anhydride and tetrabutylammonium nitrate, followed by the transformation of C2-NO2 into C2-Cl in NH4Cl/EtOH solution. The deprotection step and ammonolysis of C6-Cl were accomplished in NH3/CH3OH. The separation of α-anomer, expensive starting materials and chromatography are not required. Moreover, cladribine could be produced on a 100 gram scale with maintained yield, indicating good potential in industrial applications.
2016, 33(11): 1279-1283
doi: 10.11944/j.issn.1000-0518.2016.11.160035
Abstract:
A novel method for the synthesis of 3,3-difluoro-2-oxindoles was developed. 2-Bromo-2,2-difluoro-N-phenylacetamide was prepared from neat simple aromatic amines with ethyl bromodifluoroacetate. Reflux of the product in CH3CN with CH3I for 24 h gave 2-bromo-2,2-difluoro-N-methyl-N-phenylacetamide in 75%~90% yields. In the presence of 3.0 chemometric number sodium formaldehyde sulfoxylate, this key intermediate undergoes intramolecular radical cyclization in aqueous solution(N,N-dimethylformamide/H2O) and affords the final product 3,3-difluoro-1-methylindolin-2-ones in 53%~72% yields. This method can be performed in aqueous solution from commercially available and affordable starting materials without any metal catalysts. It shows potential in industrial production of 3,3-difluoro-2-oxindoles.
A novel method for the synthesis of 3,3-difluoro-2-oxindoles was developed. 2-Bromo-2,2-difluoro-N-phenylacetamide was prepared from neat simple aromatic amines with ethyl bromodifluoroacetate. Reflux of the product in CH3CN with CH3I for 24 h gave 2-bromo-2,2-difluoro-N-methyl-N-phenylacetamide in 75%~90% yields. In the presence of 3.0 chemometric number sodium formaldehyde sulfoxylate, this key intermediate undergoes intramolecular radical cyclization in aqueous solution(N,N-dimethylformamide/H2O) and affords the final product 3,3-difluoro-1-methylindolin-2-ones in 53%~72% yields. This method can be performed in aqueous solution from commercially available and affordable starting materials without any metal catalysts. It shows potential in industrial production of 3,3-difluoro-2-oxindoles.
2016, 33(11): 1284-1288
doi: 10.11944/j.issn.1000-0518.2016.11.160008
Abstract:
One-pot green synthesis of benzil catalyzed by Co(Salen) from benzoin in alcohol-water was developed. The products was confirmed by 1H NMR, 13C NMR, IR, HRMS and XRD. The orthogonal experimental design gives the optimal reaction conditions about the catalyst loading, reaction time, solvents, reaction temperature, and the amount of potassium hydroxide. The best conditions is Co(Salen) catalyst, 80% alcohol-water, 50 minutes and 70℃. The highest yield of 76.5% could be obtained under that conditions. The catalyst can be recycled at least five times up to the 74.2% yield. It is a green method and novel protocol to synthesize benzil.
One-pot green synthesis of benzil catalyzed by Co(Salen) from benzoin in alcohol-water was developed. The products was confirmed by 1H NMR, 13C NMR, IR, HRMS and XRD. The orthogonal experimental design gives the optimal reaction conditions about the catalyst loading, reaction time, solvents, reaction temperature, and the amount of potassium hydroxide. The best conditions is Co(Salen) catalyst, 80% alcohol-water, 50 minutes and 70℃. The highest yield of 76.5% could be obtained under that conditions. The catalyst can be recycled at least five times up to the 74.2% yield. It is a green method and novel protocol to synthesize benzil.
2016, 33(11): 1289-1294
doi: 10.11944/j.issn.1000-0518.2016.11.160026
Abstract:
Pyridine derivatives were synthesized in a one-pot reaction from oxime acetates and benzyl alcohols in the presence of copper(Ⅱ) trifluoromethanesulfonate[Cu(OTf)2] catalyst. The effect of catalysts and their dosage, raw material ratios, solvents, and temperatures on the yield were investigated. The target compound 2,4,6-trisubstituted pyridine was obtained in 88% yield under the optimum condition. The molecular structures of products were analyzed by mass spectrometry and nuclear magnetic resonance spectroscopy(1H NMR and 13C NMR). The method has several advantages:commerically available materials, easy operation, mild reaction conditions, good yields and a wide range of functional group tolerance.
Pyridine derivatives were synthesized in a one-pot reaction from oxime acetates and benzyl alcohols in the presence of copper(Ⅱ) trifluoromethanesulfonate[Cu(OTf)2] catalyst. The effect of catalysts and their dosage, raw material ratios, solvents, and temperatures on the yield were investigated. The target compound 2,4,6-trisubstituted pyridine was obtained in 88% yield under the optimum condition. The molecular structures of products were analyzed by mass spectrometry and nuclear magnetic resonance spectroscopy(1H NMR and 13C NMR). The method has several advantages:commerically available materials, easy operation, mild reaction conditions, good yields and a wide range of functional group tolerance.
2016, 33(11): 1295-1302
doi: 10.11944/j.issn.1000-0518.2016.11.160022
Abstract:
The composite Ce-TiO2 support was prepared through solvothermal treament of Ce(NO3)3 and butyl titanate. A series of V2O5/Ce-TiO2 catalysts with different vanadium loadings were obtained by incipient impregnation with ammonium metavanadate solution. The catalytic properties of V2O5/Ce-TiO2 for selective oxidation of methanol to dimethoxymethane(DMM) were investigated. The V2O5/Ce-TiO2 catalysts were characterized by XRD, UV-Vis, H2-TPR, and NH3-TPD. The results show that the dispersion of vanadium species is improved on the surface of Ce modified TiO2. The interaction between vanadium species and supports is changed. The reduction temperature increases with the increasing Ce content. The Ce content in modified TiO2 does not affect the acidity of the V2O5 supported catalysts, but the acidity of the catalysts decreases with the increasing of V2O5 content. For the catalyst of 10V/1Ce-TiO2(The numbers 10 and 1 represent the mass percentage of V2O5 in the catalyst and molar ratio of Ce and TiO2, respectively), the methanol conversion and DMM selectivity reach 39.6% and 99.9%, respectively, at 160℃.
The composite Ce-TiO2 support was prepared through solvothermal treament of Ce(NO3)3 and butyl titanate. A series of V2O5/Ce-TiO2 catalysts with different vanadium loadings were obtained by incipient impregnation with ammonium metavanadate solution. The catalytic properties of V2O5/Ce-TiO2 for selective oxidation of methanol to dimethoxymethane(DMM) were investigated. The V2O5/Ce-TiO2 catalysts were characterized by XRD, UV-Vis, H2-TPR, and NH3-TPD. The results show that the dispersion of vanadium species is improved on the surface of Ce modified TiO2. The interaction between vanadium species and supports is changed. The reduction temperature increases with the increasing Ce content. The Ce content in modified TiO2 does not affect the acidity of the V2O5 supported catalysts, but the acidity of the catalysts decreases with the increasing of V2O5 content. For the catalyst of 10V/1Ce-TiO2(The numbers 10 and 1 represent the mass percentage of V2O5 in the catalyst and molar ratio of Ce and TiO2, respectively), the methanol conversion and DMM selectivity reach 39.6% and 99.9%, respectively, at 160℃.
2016, 33(11): 1303-1309
doi: 10.11944/j.issn.1000-0518.2016.11.160033
Abstract:
Oxovanadium complex[VO(C6H9O2)(Tp4I)]·2H2O(Tp4I=tri-(4-lodopyrazole)borate) was designed and synthesized. The spectral and structural characters of the complex were analyzed by elemental analysis, IR spectroscopy, UV spectroscopy, thermogravimetric analysis, X-ray powder diffraction and single crystal X-ray diffraction analysis. The structural analysis shows that the complex has an octahedron geometry with hexa-coordinated metal. Ligand tri-(4-lodopyrazole)borate adopts a tridentate chelating coordination mode. The complex exhibits good catalytic activity in the mimic bromination of phenol red, and the reaction rate constant is 2.424×102 (mol/L)-2·s-1. Meanwhile, the reaction system was applied in the hydrogen peroxide determination.
Oxovanadium complex[VO(C6H9O2)(Tp4I)]·2H2O(Tp4I=tri-(4-lodopyrazole)borate) was designed and synthesized. The spectral and structural characters of the complex were analyzed by elemental analysis, IR spectroscopy, UV spectroscopy, thermogravimetric analysis, X-ray powder diffraction and single crystal X-ray diffraction analysis. The structural analysis shows that the complex has an octahedron geometry with hexa-coordinated metal. Ligand tri-(4-lodopyrazole)borate adopts a tridentate chelating coordination mode. The complex exhibits good catalytic activity in the mimic bromination of phenol red, and the reaction rate constant is 2.424×102 (mol/L)-2·s-1. Meanwhile, the reaction system was applied in the hydrogen peroxide determination.
2016, 33(11): 1310-1315
doi: 10.11944/j.issn.1000-0518.2016.11.160326
Abstract:
A series of Eu2+ single doped and Tm3+ co-doped CaAlSiN3 phosphors were synthesized by high temperature solid-reaction method. Photoluminescence, afterglow emission and thermoluminescence glow curve investigations indicate that CaAlSiN3:0.1%Eu2+ sample possesses excellent photoluminescence properties with broad emission band located at about 630 nm. The introduction of Tm3+ codopant creates new emission bands located 654 nm and 800 nm, respectively, which are originated from Tm3+ in CaAlSiN3 matrix. However, the Tm3+ codopant causes the disappearance of 89.0℃ thermoluminescence glow peak, which indicates that the introduction of Tm3+ has changed the defect distribution and their concentrations, thus deceasing the visible 630 nm red light afterglow of CaAlSiN3:Eu2+.
A series of Eu2+ single doped and Tm3+ co-doped CaAlSiN3 phosphors were synthesized by high temperature solid-reaction method. Photoluminescence, afterglow emission and thermoluminescence glow curve investigations indicate that CaAlSiN3:0.1%Eu2+ sample possesses excellent photoluminescence properties with broad emission band located at about 630 nm. The introduction of Tm3+ codopant creates new emission bands located 654 nm and 800 nm, respectively, which are originated from Tm3+ in CaAlSiN3 matrix. However, the Tm3+ codopant causes the disappearance of 89.0℃ thermoluminescence glow peak, which indicates that the introduction of Tm3+ has changed the defect distribution and their concentrations, thus deceasing the visible 630 nm red light afterglow of CaAlSiN3:Eu2+.
2016, 33(11): 1316-1321
doi: 10.11944/j.issn.1000-0518.2016.11.160047
Abstract:
Nitrogen/oxygen co-doped porous carbons were prepared for supercapacitor electrode using waste crab shells as the carbon source and KOH as the activated agent. The effects of the pyrolysis temperature on the yield, the porous structures and the nitrogen/oxygen content of the obtained carbons were investigated with the fixed mass ratio of crab shells and KOH as 5:3. The results show that the specific surface area and pore volume of the as-synthesized carbons are increased, while their nitrogen/oxygen contents are decreased when the pyrolysis temperature is increased from 500 to 700℃. Electrochemical behaviors were determined using cyclic voltammetry and galvanostatic charge-discharge measurements. The results demonstrate that the nitrogen/oxygen content and the porosity of the carbons have important effects on their electrochemical performances. The sample with the pyrolysis temperature fixed at 600℃ exhibits the specific surface area of 612 m2/g, the nitrogen content of 3.53% as well as the oxygen content of 32.8%. Its specific capacitance reaches 310 F/g at the current density of 50 mA/g and exhibits the long-term stability with 95% capacitance retention after 1000 cycles. It is obvious that the porous structure and the nitrogen/oxygen contents of the obtained carbons can be controlled by adjusting the pyrolysis temperature, and their electrochemical performances depend on the synergistic effects of the porosity and the surface properties.
Nitrogen/oxygen co-doped porous carbons were prepared for supercapacitor electrode using waste crab shells as the carbon source and KOH as the activated agent. The effects of the pyrolysis temperature on the yield, the porous structures and the nitrogen/oxygen content of the obtained carbons were investigated with the fixed mass ratio of crab shells and KOH as 5:3. The results show that the specific surface area and pore volume of the as-synthesized carbons are increased, while their nitrogen/oxygen contents are decreased when the pyrolysis temperature is increased from 500 to 700℃. Electrochemical behaviors were determined using cyclic voltammetry and galvanostatic charge-discharge measurements. The results demonstrate that the nitrogen/oxygen content and the porosity of the carbons have important effects on their electrochemical performances. The sample with the pyrolysis temperature fixed at 600℃ exhibits the specific surface area of 612 m2/g, the nitrogen content of 3.53% as well as the oxygen content of 32.8%. Its specific capacitance reaches 310 F/g at the current density of 50 mA/g and exhibits the long-term stability with 95% capacitance retention after 1000 cycles. It is obvious that the porous structure and the nitrogen/oxygen contents of the obtained carbons can be controlled by adjusting the pyrolysis temperature, and their electrochemical performances depend on the synergistic effects of the porosity and the surface properties.
2016, 33(11): 1322-1328
doi: 10.11944/j.issn.1000-0518.2016.11.160069
Abstract:
6-(4'-Nicotinamido)phenyl-3-(3'-pyridinyl)pyridazino[3,2-c]1,2,4-triazole(K2) was prepared by 3-(4-bromophenyl)-6-chloropyridazine and nicotinic hydrazide, and characterized by infrared spectroscopy, 1H- and 13C-nuclear magnetic resonance spectroscopy. The adsorptive properties and the selectivity of compound K2 for the separation of Hg2+ were investigated. The results indicate that the maximum adsorption capacity is 46.50 mg/g. The adsorption capacity reaches equilibrium within 20 min at pH 6.0~8.0. Using 0.50 mol/L HCl and 1.00 mol/L thiourea as desorption solvent, the desorption rate is more than 97%. The selective factor(α) values of Hg(Ⅱ) for Cd(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Zn(Ⅱ) and Mn(Ⅱ) are 5.67, 6.70, 10.20, 8.90 and 9.21, respectively. These indicate that compound K2 has excellent adsorption and selective properties. The experimental data follow the Langmuir adsorption model and a pseudo-second-order model.
6-(4'-Nicotinamido)phenyl-3-(3'-pyridinyl)pyridazino[3,2-c]1,2,4-triazole(K2) was prepared by 3-(4-bromophenyl)-6-chloropyridazine and nicotinic hydrazide, and characterized by infrared spectroscopy, 1H- and 13C-nuclear magnetic resonance spectroscopy. The adsorptive properties and the selectivity of compound K2 for the separation of Hg2+ were investigated. The results indicate that the maximum adsorption capacity is 46.50 mg/g. The adsorption capacity reaches equilibrium within 20 min at pH 6.0~8.0. Using 0.50 mol/L HCl and 1.00 mol/L thiourea as desorption solvent, the desorption rate is more than 97%. The selective factor(α) values of Hg(Ⅱ) for Cd(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Zn(Ⅱ) and Mn(Ⅱ) are 5.67, 6.70, 10.20, 8.90 and 9.21, respectively. These indicate that compound K2 has excellent adsorption and selective properties. The experimental data follow the Langmuir adsorption model and a pseudo-second-order model.
2016, 33(11): 1329-1336
doi: 10.11944/j.issn.1000-0518.2016.11.160082
Abstract:
A system based on yttria-stabilized zirconia(YSZ) membrane electrode and external pressure balanced Ag/AgCl electrode has been developed for in-situ pH measurement in high temperature aqueous solutions. The pH values of H3BO3\LiOH solutions at 473.15 K to 573.15 K were measured by this system and compared with thermodynamically calculated pH values. The precise pH measurement is achieved when temperature is higher than 548.15 K. While below 548.15 K, deviation exists due to the large resistance of YSZ ceramic membrane and it increases with decreasing temperature. The mechanism of pH measurement in high temperature aqueous solutions is also discussed.
A system based on yttria-stabilized zirconia(YSZ) membrane electrode and external pressure balanced Ag/AgCl electrode has been developed for in-situ pH measurement in high temperature aqueous solutions. The pH values of H3BO3\LiOH solutions at 473.15 K to 573.15 K were measured by this system and compared with thermodynamically calculated pH values. The precise pH measurement is achieved when temperature is higher than 548.15 K. While below 548.15 K, deviation exists due to the large resistance of YSZ ceramic membrane and it increases with decreasing temperature. The mechanism of pH measurement in high temperature aqueous solutions is also discussed.
2016, 33(11): 1337-1339
doi: 10.11944/j.issn.1000-0518.2016.11.160136
Abstract:
A series of Pt supported catalysts was prepared by galvanic method with the precursor of hydrotalcite. Pt is well dispersed in the catalyst. Besides, CO oxidation was employed as a probe reaction and the performance of the catalysts with different Pt loading was studied. The results show that CO can be completely oxidized at 90℃ when the loading amount of Pt is 5%.
A series of Pt supported catalysts was prepared by galvanic method with the precursor of hydrotalcite. Pt is well dispersed in the catalyst. Besides, CO oxidation was employed as a probe reaction and the performance of the catalysts with different Pt loading was studied. The results show that CO can be completely oxidized at 90℃ when the loading amount of Pt is 5%.
2016, 33(11): 1340-1342
doi: 10.11944/j.issn.1000-0518.2016.11.160148
Abstract:
Mesoporous carbon with monolithic structures were prepared using abandoned crab shells as a template. And then Fe3O4 nanoparticles inside those monolithic mesopores were synthesized by the confined in-situ synthetic strategy. The properties and structure of Fe3O4 nanoparticles on nesoporous narbon were characterized by scanning electronic microscopy(SEM), transmission electron microscope(TEM) and X-ray diffraction(XRD). The results show that the pores have a monolithic structure. The diameters of the pores are ca. 40~50 nm and their lengths are ca. 50 μm to 200 μm. The nanoparticles are proven to be Fe3O4 with 10 nm in diameter, which have good size monodispersity and are evenly distributed inside the pores. This method features simple and environmental benignity.
Mesoporous carbon with monolithic structures were prepared using abandoned crab shells as a template. And then Fe3O4 nanoparticles inside those monolithic mesopores were synthesized by the confined in-situ synthetic strategy. The properties and structure of Fe3O4 nanoparticles on nesoporous narbon were characterized by scanning electronic microscopy(SEM), transmission electron microscope(TEM) and X-ray diffraction(XRD). The results show that the pores have a monolithic structure. The diameters of the pores are ca. 40~50 nm and their lengths are ca. 50 μm to 200 μm. The nanoparticles are proven to be Fe3O4 with 10 nm in diameter, which have good size monodispersity and are evenly distributed inside the pores. This method features simple and environmental benignity.
