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2014 Volume 31 Issue 10
2014, 31(10): 1115-1122
doi: 10.3724/SP.J.1095.2014.30632
Abstract:
The structures and electrochemical performance of lithium vanadyl phosphate(α-LiVOPO4, β-LiVOPO4 and αⅠ-LiVOPO4) were presented. High temperature solid state, chemical reduction, sol-gel, solvothermal and ion exchange methods for the synthesis of LiVOPO4 were reviewed. The modification research status of LiVOPO 4 was summarized in brief. Finally the prospect of application tendency was depicted.
The structures and electrochemical performance of lithium vanadyl phosphate(α-LiVOPO4, β-LiVOPO4 and αⅠ-LiVOPO4) were presented. High temperature solid state, chemical reduction, sol-gel, solvothermal and ion exchange methods for the synthesis of LiVOPO4 were reviewed. The modification research status of LiVOPO 4 was summarized in brief. Finally the prospect of application tendency was depicted.
2014, 31(10): 1123-1134
doi: 10.3724/SP.J.1095.2014.30658
Abstract:
Due to their excellent photostability and photophysical properties, the rhodamine fluorochrome has attracted considerable interest from chemists. Spirocyclic derivatives of rhodamine dyes are useful sensing platforms since the ring-opening process leads to a turn-on fluorescence change. A multi-branched rhodamine derivative with an appropriate ligand on spirolactam ring that is capable of binding a single metal ion is expected to display enhanced absorbance as well as fluorescence properties required for trace metal analysis. This review provides an insight to the design and fabrication of the multi-branched rhodamine sensing system for metal-ions applications. The perspective for futher research of rhodamine-based cell imaging optical sensors are also discussed.
Due to their excellent photostability and photophysical properties, the rhodamine fluorochrome has attracted considerable interest from chemists. Spirocyclic derivatives of rhodamine dyes are useful sensing platforms since the ring-opening process leads to a turn-on fluorescence change. A multi-branched rhodamine derivative with an appropriate ligand on spirolactam ring that is capable of binding a single metal ion is expected to display enhanced absorbance as well as fluorescence properties required for trace metal analysis. This review provides an insight to the design and fabrication of the multi-branched rhodamine sensing system for metal-ions applications. The perspective for futher research of rhodamine-based cell imaging optical sensors are also discussed.
2014, 31(10): 1135-1142
doi: 10.3724/SP.J.1095.2014.30657
Abstract:
Design and synthesis of well-defined polymers are of the utmost importance for the reliable establishment of macromolecular structure-properties relationships. This work reports a novel strategy to synthesize cyclic random copolyesters with triethylsilyloxy groups. The ring-opening polymerization of a mixture of εCL and functional monomer γ-triethylsilyloxy-ε-caprolactone(γ-Et3SiOεCL) was initiated by 2,2-dibutyl-2-stanna-1, 3-dioxepane(DSDOP) to obtain a precursor, i. e., a living cyclic copolyester(LCP(εCLcoγEt3SiOεCL)). When the comonomers were converted completely, a fresh feed of α-(1-acryloyloxyethyl)-ε-caprolactone(αAEεCL) was added to the polymerization medium to achieve a living cyclic block copolyester, poly((εCLcoγEt3SiOεCL)-b-(αAEεCL)). Finally, stable functional cyclic copolyester free of tin dialkoxides, i. e., cP(εCLcoγEt3SiOεCL)(Mn,NMR=28500), was synthesized by intramolecular photo cross-linking of acrylic unsaturations in the proximity of the living cyclic chain under the irradiation of ultraviolet light. The structure and properties of the copolymers were characterized by size-exclusion chromatography(SEC), proton nuclear magnetic resonance spectroscopy(1H NMR), and differential scanning calorimetry(DSC) technologies. The strategy herein disclosed has been successfully tested for the synthesis of functional cyclic copolyesters with high relative molecular mass in high efficiency.
Design and synthesis of well-defined polymers are of the utmost importance for the reliable establishment of macromolecular structure-properties relationships. This work reports a novel strategy to synthesize cyclic random copolyesters with triethylsilyloxy groups. The ring-opening polymerization of a mixture of εCL and functional monomer γ-triethylsilyloxy-ε-caprolactone(γ-Et3SiOεCL) was initiated by 2,2-dibutyl-2-stanna-1, 3-dioxepane(DSDOP) to obtain a precursor, i. e., a living cyclic copolyester(LCP(εCLcoγEt3SiOεCL)). When the comonomers were converted completely, a fresh feed of α-(1-acryloyloxyethyl)-ε-caprolactone(αAEεCL) was added to the polymerization medium to achieve a living cyclic block copolyester, poly((εCLcoγEt3SiOεCL)-b-(αAEεCL)). Finally, stable functional cyclic copolyester free of tin dialkoxides, i. e., cP(εCLcoγEt3SiOεCL)(Mn,NMR=28500), was synthesized by intramolecular photo cross-linking of acrylic unsaturations in the proximity of the living cyclic chain under the irradiation of ultraviolet light. The structure and properties of the copolymers were characterized by size-exclusion chromatography(SEC), proton nuclear magnetic resonance spectroscopy(1H NMR), and differential scanning calorimetry(DSC) technologies. The strategy herein disclosed has been successfully tested for the synthesis of functional cyclic copolyesters with high relative molecular mass in high efficiency.
2014, 31(10): 1143-1148
doi: 10.3724/SP.J.1095.2014.30659
Abstract:
The chitosan(Cs) and acrylic acid(AA) were used to prepare the composite hydrogel(Cs-PAA) by radical polymerization method. The influences of reaction temperature, neutralization degree of acrylic acid, amounts of cross-linking agent and acrylic acid on the swelling degree of the composite hydrogels were investigated. In addition, the controlled release behaviors of prepared hydrogels for niacin were evaluated. The swelling degree of prepared hydrogels is up to 1228 g/g. It exhibits excellent pH and ionic strength sensitivity. The cumulative release rate in a pH=6.86 buffer solution is significantly higher than that in a pH=1.8 buffer solution. Therefore, the hydrogels can be used as carriers of intestinal oral drugs.
The chitosan(Cs) and acrylic acid(AA) were used to prepare the composite hydrogel(Cs-PAA) by radical polymerization method. The influences of reaction temperature, neutralization degree of acrylic acid, amounts of cross-linking agent and acrylic acid on the swelling degree of the composite hydrogels were investigated. In addition, the controlled release behaviors of prepared hydrogels for niacin were evaluated. The swelling degree of prepared hydrogels is up to 1228 g/g. It exhibits excellent pH and ionic strength sensitivity. The cumulative release rate in a pH=6.86 buffer solution is significantly higher than that in a pH=1.8 buffer solution. Therefore, the hydrogels can be used as carriers of intestinal oral drugs.
2014, 31(10): 1149-1155
doi: 10.3724/SP.J.1095.2014.30617
Abstract:
The prevention of hospital-acquired infection attributable to indwelling urethral catheter use has recently received increased attention. For controlled release of antibacterial drugs, antibacterial films with a thickness less than 500 nm on urethral catheter were directly constructed by layer-by-layer deposition of poly(allylamine hydrochloride) and dextran(PAH-D) microgels with hyaluronic acid(HA). PAH-D/HA multilayer films can load negatively charged antibacterial drugs such as ceflriaxone sodium(CTX) in 2 min based on electrostatic interaction between PAH-D microgels and CTX molecules and then release them in 3 h in physiological saline. Direct deposition of microgel films and incorporation of CTX endow the multilayer micro films with an effective antibacterial performance.
The prevention of hospital-acquired infection attributable to indwelling urethral catheter use has recently received increased attention. For controlled release of antibacterial drugs, antibacterial films with a thickness less than 500 nm on urethral catheter were directly constructed by layer-by-layer deposition of poly(allylamine hydrochloride) and dextran(PAH-D) microgels with hyaluronic acid(HA). PAH-D/HA multilayer films can load negatively charged antibacterial drugs such as ceflriaxone sodium(CTX) in 2 min based on electrostatic interaction between PAH-D microgels and CTX molecules and then release them in 3 h in physiological saline. Direct deposition of microgel films and incorporation of CTX endow the multilayer micro films with an effective antibacterial performance.
2014, 31(10): 1156-1163
doi: 10.3724/SP.J.1095.2014.40175
Abstract:
An electron-deficient moiety, namely dibenzothiophene-S,S-dioxide(SO), has been incorporated into the main chain of poly(spirobifluorene)s(PSFs) via its 2 and 8 positions to form a series of copolymers with different SO content(PSF-28SO-3, PSF-28SO-5, PSF-28SO-7 and PSF-28SO-10). Unlike the 3,7-linked analogue that mainly reveals a charge transfer(CT) emission from the electron-rich tetraoctyloxyfluorene side chain to the electron-deficient SO unit in the main chain, the resultant polymers PSF-28SO-3~PSF-28SO-10 show emissions not only from the local excited(LE) states but also from the CT ones due to the unique 2,8-linkage. Consequently, near-white emission is achieved for these copolymers. Among them, PSF-28SO-10 has the best device performance, giving a luminous efficiency of 0.58 cd/A and Commission Internationale de L'Eclairage(CIE) coordinates of(0.25,0.36).
An electron-deficient moiety, namely dibenzothiophene-S,S-dioxide(SO), has been incorporated into the main chain of poly(spirobifluorene)s(PSFs) via its 2 and 8 positions to form a series of copolymers with different SO content(PSF-28SO-3, PSF-28SO-5, PSF-28SO-7 and PSF-28SO-10). Unlike the 3,7-linked analogue that mainly reveals a charge transfer(CT) emission from the electron-rich tetraoctyloxyfluorene side chain to the electron-deficient SO unit in the main chain, the resultant polymers PSF-28SO-3~PSF-28SO-10 show emissions not only from the local excited(LE) states but also from the CT ones due to the unique 2,8-linkage. Consequently, near-white emission is achieved for these copolymers. Among them, PSF-28SO-10 has the best device performance, giving a luminous efficiency of 0.58 cd/A and Commission Internationale de L'Eclairage(CIE) coordinates of(0.25,0.36).
2014, 31(10): 1164-1170
doi: 10.3724/SP.J.1095.2014.30605
Abstract:
Fatty acid europium complexes were synthesized with hexanoic acid, octanoic acid, lauric acid or stearic acid as the ligands. The polyethylene(PE), polypropylene(PP) or polystyrene(PS) photoluminescence composites doped with europium complexes were prepared by the Haake torque rheometer. The influences of ligands, europium complexes and polymer matrixes on the appearance, transparency and luminescence properties of the composites were investigated. These fatty acid europium complexes and their composites emit strong characteristic luminescence of europium ions 5D0→7F1 and 5D0→7F2 respectively, at 593, 617 nm under ultraviolet light excitation. The luminescence of europium complexes and their composites are less affected by the chain length of the fatty acid. The PP or PE composites emit only characteristic red fluorescence of the Eu3+ ions under ultraviolet light, while a rosy fluorescence emission of the PS composites is demonstrated to arise from a combination of strong red light-emitting of the Eu3+ ions and weak blue-violet light-emitting of the PS matrix.
Fatty acid europium complexes were synthesized with hexanoic acid, octanoic acid, lauric acid or stearic acid as the ligands. The polyethylene(PE), polypropylene(PP) or polystyrene(PS) photoluminescence composites doped with europium complexes were prepared by the Haake torque rheometer. The influences of ligands, europium complexes and polymer matrixes on the appearance, transparency and luminescence properties of the composites were investigated. These fatty acid europium complexes and their composites emit strong characteristic luminescence of europium ions 5D0→7F1 and 5D0→7F2 respectively, at 593, 617 nm under ultraviolet light excitation. The luminescence of europium complexes and their composites are less affected by the chain length of the fatty acid. The PP or PE composites emit only characteristic red fluorescence of the Eu3+ ions under ultraviolet light, while a rosy fluorescence emission of the PS composites is demonstrated to arise from a combination of strong red light-emitting of the Eu3+ ions and weak blue-violet light-emitting of the PS matrix.
2014, 31(10): 1171-1176
doi: 10.3724/SP.J.1095.2014.30630
Abstract:
A novel donor-π-acceptor(D-π-A) type carbazole derivative(L) was designed and synthesized through alkylation, nitration, iodination, Heck cross-coupling reaction and hydrazine hydrate reduction reaction of carbazole. Compound L was characterized by FT-IR, 1H NMR, 13C NMR and MS. The optical, electrochemical properties and electronic cloud distribution of compound L were preliminarily studied by means of UV-Vis absorption spectra, fluorescent emission spectra, cyclic voltammogram and theoretical calculation. The results revealed that UV-Vis absorption and fluorescence spectra of compound L red-shifted with the increasing solvent polarity.
A novel donor-π-acceptor(D-π-A) type carbazole derivative(L) was designed and synthesized through alkylation, nitration, iodination, Heck cross-coupling reaction and hydrazine hydrate reduction reaction of carbazole. Compound L was characterized by FT-IR, 1H NMR, 13C NMR and MS. The optical, electrochemical properties and electronic cloud distribution of compound L were preliminarily studied by means of UV-Vis absorption spectra, fluorescent emission spectra, cyclic voltammogram and theoretical calculation. The results revealed that UV-Vis absorption and fluorescence spectra of compound L red-shifted with the increasing solvent polarity.
2014, 31(10): 1177-1184
doi: 10.3724/SP.J.1095.2014.40050
Abstract:
On the basis of a fluorinated ligand, namely 2-(4'-fluorophenyl)-1-phenyl-benzoimidazole, a green-emitting iridium complex mer-Ir(FPBI)3 with meridional configuration has been successfully synthesized under a temperature higher than 200℃, which is confirmed by both 1H NMR and single crystal X-ray diffraction analysis. Different from previously-reported meridional iridium complexes(< 0.1), noticeably, mer-Ir(FPBI)3 shows a photoluminescent quantum yield as high as 0.46. Therefore, highly efficient phosphorescent organic light-emitting diodes(PhOLEDs) are realized by tuning the doping concentration of mer-Ir(FPBI)3 into 4, 4'-N, N'-dicarbazolebiphenyl(CBP), revealing a maximum current efficiency of 38.5 cd/A(11.8%) with the corresponding Commission Internationale de L'Eclairage(CIE) coordinates of(0.29, 0.58).
On the basis of a fluorinated ligand, namely 2-(4'-fluorophenyl)-1-phenyl-benzoimidazole, a green-emitting iridium complex mer-Ir(FPBI)3 with meridional configuration has been successfully synthesized under a temperature higher than 200℃, which is confirmed by both 1H NMR and single crystal X-ray diffraction analysis. Different from previously-reported meridional iridium complexes(< 0.1), noticeably, mer-Ir(FPBI)3 shows a photoluminescent quantum yield as high as 0.46. Therefore, highly efficient phosphorescent organic light-emitting diodes(PhOLEDs) are realized by tuning the doping concentration of mer-Ir(FPBI)3 into 4, 4'-N, N'-dicarbazolebiphenyl(CBP), revealing a maximum current efficiency of 38.5 cd/A(11.8%) with the corresponding Commission Internationale de L'Eclairage(CIE) coordinates of(0.29, 0.58).
2014, 31(10): 1185-1190
doi: 10.3724/SP.J.1095.2014.30651
Abstract:
Thirteen phenyl(thiophen-2-yl) methanone derivatives were designed and synthesized by classic synthetic methods, in which compounds 9b, 10b and 11b are new. All target structures were confirmed by ESI-MS, 1H NMR and 13C NMR. Their in vitro cytoprotective activities against H2O2-induced injury on human umbilical vein endothelial cells(HUVECs) were tested. And the results show that p-methoxy groups and two chlorine atoms substituted on the phenyl ring express preferable protective activity. The preliminary structureactivity relationships results show that the position, number and type of substituents on the core structure have remarkable effects on protective activities against H2O2-induced injury on HUVECs.
Thirteen phenyl(thiophen-2-yl) methanone derivatives were designed and synthesized by classic synthetic methods, in which compounds 9b, 10b and 11b are new. All target structures were confirmed by ESI-MS, 1H NMR and 13C NMR. Their in vitro cytoprotective activities against H2O2-induced injury on human umbilical vein endothelial cells(HUVECs) were tested. And the results show that p-methoxy groups and two chlorine atoms substituted on the phenyl ring express preferable protective activity. The preliminary structureactivity relationships results show that the position, number and type of substituents on the core structure have remarkable effects on protective activities against H2O2-induced injury on HUVECs.
2014, 31(10): 1191-1194
doi: 10.3724/SP.J.1095.2014.30635
Abstract:
6-(3-Aminophenyl)-4,5-dihydropyridazin-3(2H)-one(1) has been synthesized by using benzene and succinic anhydride as starting materials via a three-step process including Friedel-Crafts acylation, nitration, reduction with hydrazine hydrate in an overall yield of 58.3%. Under catalysis of Raney Ni, β-m-nitrobenzoylpropionic acid(3) reacted with hydrazine hydrate to give compound 1 by one step of nitro reduction and ring closing. The effects of the amount of hydrazine and reaction time on the yield of above reaction have been explored. When the reaction was refluxed for 4 h with molar ratio of hydrazine to compound 3 at 11.7:1, the yield of compound 1 was up to 82.7%.
6-(3-Aminophenyl)-4,5-dihydropyridazin-3(2H)-one(1) has been synthesized by using benzene and succinic anhydride as starting materials via a three-step process including Friedel-Crafts acylation, nitration, reduction with hydrazine hydrate in an overall yield of 58.3%. Under catalysis of Raney Ni, β-m-nitrobenzoylpropionic acid(3) reacted with hydrazine hydrate to give compound 1 by one step of nitro reduction and ring closing. The effects of the amount of hydrazine and reaction time on the yield of above reaction have been explored. When the reaction was refluxed for 4 h with molar ratio of hydrazine to compound 3 at 11.7:1, the yield of compound 1 was up to 82.7%.
2014, 31(10): 1195-1202
doi: 10.3724/SP.J.1095.2014.30647
Abstract:
The catalytic properties of 2-phenyl-2H-1,2,3-triazole-4-carbaldehyde functionalized mesoporous molecular sieve MCM-41 materials and cobalt acetate in the nitroaldol(Henry) reaction are reported. The catalyst was characterized by methods of Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD). The reaction conditions such as metal salts, different solvents were investigated at room temperature. And the catalyst can be separated by simple filtration and reused for several times without much loss in performance with the yield up to 80.5%.
The catalytic properties of 2-phenyl-2H-1,2,3-triazole-4-carbaldehyde functionalized mesoporous molecular sieve MCM-41 materials and cobalt acetate in the nitroaldol(Henry) reaction are reported. The catalyst was characterized by methods of Fourier transform infrared spectroscopy(FT-IR) and X-ray diffraction(XRD). The reaction conditions such as metal salts, different solvents were investigated at room temperature. And the catalyst can be separated by simple filtration and reused for several times without much loss in performance with the yield up to 80.5%.
2014, 31(10): 1203-1209
doi: 10.3724/SP.J.1095.2014.40046
Abstract:
3,4-Dihydropy-rimidine-2(1H)-one was synthesized from substituted benzaldehyde, ethylacetoacetate and urea using phosphotungstic acid(H3PW12O40) supported on SiO2 as a novel eco-friendly catalyst prepared by a sol-gel technique. The influences of the molar ratio of reactants, reaction temperature, catalyst loading and reaction time were discussed. H3PW12O40/SiO2 is a good catalyst for the synthesis of 3,4-dihydropyrimidine-2(1H)-one with the yield of 73.1%~88.4% under optimized conditions. The catalyst was characterized by IR, XRD and SEM, and the products were characterized by 1H NMR, IR and MS.
3,4-Dihydropy-rimidine-2(1H)-one was synthesized from substituted benzaldehyde, ethylacetoacetate and urea using phosphotungstic acid(H3PW12O40) supported on SiO2 as a novel eco-friendly catalyst prepared by a sol-gel technique. The influences of the molar ratio of reactants, reaction temperature, catalyst loading and reaction time were discussed. H3PW12O40/SiO2 is a good catalyst for the synthesis of 3,4-dihydropyrimidine-2(1H)-one with the yield of 73.1%~88.4% under optimized conditions. The catalyst was characterized by IR, XRD and SEM, and the products were characterized by 1H NMR, IR and MS.
2014, 31(10): 1210-1215
doi: 10.3724/SP.J.1095.2014.30648
Abstract:
A new molybdenum-vanadium polyoxometalate[PⅤMo7ⅥMoⅤV8ⅣO44][Ni(Phen)2OH]4·3H2O(1) was prepared under hydrothermal conditions, and characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. The title compound crystallized in a triclinic system, P-1 space group, a=1.51300(11) nm, b=1.74813(15) nm, c=2.58896(18) nm, α=72.842(4)°, β=89.240(5)°, γ=72.627(5)°, V=6.2233(8) nm3, Z=1, R1=0.0962, wR2=0.2572. Compound 1 is composed of a highly reduced tetra-capped pseudo-Keggin polyoxoanion supporting four transition metal complexes. There are many hydrogen bond among polyoxoanion and water molecules, which enable the formation of three dimensional supramolecular array.
A new molybdenum-vanadium polyoxometalate[PⅤMo7ⅥMoⅤV8ⅣO44][Ni(Phen)2OH]4·3H2O(1) was prepared under hydrothermal conditions, and characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. The title compound crystallized in a triclinic system, P-1 space group, a=1.51300(11) nm, b=1.74813(15) nm, c=2.58896(18) nm, α=72.842(4)°, β=89.240(5)°, γ=72.627(5)°, V=6.2233(8) nm3, Z=1, R1=0.0962, wR2=0.2572. Compound 1 is composed of a highly reduced tetra-capped pseudo-Keggin polyoxoanion supporting four transition metal complexes. There are many hydrogen bond among polyoxoanion and water molecules, which enable the formation of three dimensional supramolecular array.
2014, 31(10): 1216-1221
doi: 10.3724/SP.J.1095.2014.30649
Abstract:
Me3SiOSiMeROSiMe3(R=CH2(CH2)7CHOCH2)(AETS) has been synthesized through a hydrosilation of 1,2-eposy-9-decene(ED) with 1,1,1,3,5,5,5-heptamethyltrisiloxane(MDHM) in the presence of hexachloroplatinic(Ⅳ) acid as the catalyst. Then a novel cationic trisiloxane surfactant with the formula Me3SiOSiMeR2OSiMe3(R2=CH2(CH2)7CHOHCH2N(CH2CH2OH)2)(CTSS) has been prepared through the ring-opening reaction of diethanolamine(DEA) with AETS. The structure of CTSS was characterized by IR and 1H NMR. The surface intension, wettability and stability in different pH of CTSS were investigated. The effect of reaction conditions on the synthesis of AETS and CTSS were investigated respectively. The optimized reaction conditions for the preparation of AETS are that the molar ratio of ED and MDHM is 1.1:1, the catalyst loading is 0.075% of the n(MDHM), the reaction time is 5 hours and the reaction temperature is 80℃. While the optimized reaction conditions to obtain CTSS are that the ratio of n(AETS) to n(DEA) is 1:1.05, the reaction time is 3 h and the reaction temperature is 80℃. CTSS can reduced the surface tension of distilled water to 20.0 mN/m at the critical micelle concentration(CMC) of 1.3×10-3 mol/L. In addition, CTSS also has better wettability and maintains stable in pH 6.5~8.0.
Me3SiOSiMeROSiMe3(R=CH2(CH2)7CHOCH2)(AETS) has been synthesized through a hydrosilation of 1,2-eposy-9-decene(ED) with 1,1,1,3,5,5,5-heptamethyltrisiloxane(MDHM) in the presence of hexachloroplatinic(Ⅳ) acid as the catalyst. Then a novel cationic trisiloxane surfactant with the formula Me3SiOSiMeR2OSiMe3(R2=CH2(CH2)7CHOHCH2N(CH2CH2OH)2)(CTSS) has been prepared through the ring-opening reaction of diethanolamine(DEA) with AETS. The structure of CTSS was characterized by IR and 1H NMR. The surface intension, wettability and stability in different pH of CTSS were investigated. The effect of reaction conditions on the synthesis of AETS and CTSS were investigated respectively. The optimized reaction conditions for the preparation of AETS are that the molar ratio of ED and MDHM is 1.1:1, the catalyst loading is 0.075% of the n(MDHM), the reaction time is 5 hours and the reaction temperature is 80℃. While the optimized reaction conditions to obtain CTSS are that the ratio of n(AETS) to n(DEA) is 1:1.05, the reaction time is 3 h and the reaction temperature is 80℃. CTSS can reduced the surface tension of distilled water to 20.0 mN/m at the critical micelle concentration(CMC) of 1.3×10-3 mol/L. In addition, CTSS also has better wettability and maintains stable in pH 6.5~8.0.
2014, 31(10): 1222-1228
doi: 10.3724/SP.J.1095.2014.30576
Abstract:
Using block copolymer P123 as the template, Tb(terbium)-loaded mesoporous TiO2 photocatalysts were prepared by the evaporation induced self-assembly method and characterized by X-ray diffraction(XRD), N2 adsorption-desorption and ultraviolet-visible(UV-Vis) absorbance spectroscopy. Tb-loaded mesoporous TiO2 with a mixture of anatase and rutile phases exhibits a high photocatalytic activity for degradation of rhodamine B(RhB) under the irradiation of visible light. It is found that 0.7% loading of Tb and 380℃ calcination temperature are the most appropriate preparation conditions for achieving high photocatalytic performance. The synergistic effect of high specific surface area, small crystallite size of mesoporous TiO2, Tb-induced charge-separation and increase of visible light absorption has improved the photocatalytic activity. The mechanism of enhancement of photocatalysis in Tb loaded TiO2 is proposed.
Using block copolymer P123 as the template, Tb(terbium)-loaded mesoporous TiO2 photocatalysts were prepared by the evaporation induced self-assembly method and characterized by X-ray diffraction(XRD), N2 adsorption-desorption and ultraviolet-visible(UV-Vis) absorbance spectroscopy. Tb-loaded mesoporous TiO2 with a mixture of anatase and rutile phases exhibits a high photocatalytic activity for degradation of rhodamine B(RhB) under the irradiation of visible light. It is found that 0.7% loading of Tb and 380℃ calcination temperature are the most appropriate preparation conditions for achieving high photocatalytic performance. The synergistic effect of high specific surface area, small crystallite size of mesoporous TiO2, Tb-induced charge-separation and increase of visible light absorption has improved the photocatalytic activity. The mechanism of enhancement of photocatalysis in Tb loaded TiO2 is proposed.
2014, 31(10): 1229-1233
doi: 10.3724/SP.J.1095.2014.30631
Abstract:
The support of C@WC core-shell structure is prepared with activated carbon as carbon source, in situ generation tungsten carbide coating on the surface of carbon material. TEM results confirm that the prepared of C@WC is core-shell structure. The composition of the shell is mainly WC containing a small amount of W. BET specific surface measurement results show that the specific surface area of C@WC is smaller than that of XC-72R, but with more of the mesoporous structure. The electrochemical surface area of Pd/C@WC is 65.47 m2/g. The Pd/C@WC catalyst electrode is more active for formic acid oxidation than Pd/C. The peak current density on Pd/C@WC is 0.222 A/cm2 which is about 0.128 A/cm2 higher than that on Pd/C. The multiple cyclic voltammograms results show that Pd/C@WC catalyst electrode has higher activity and stability compared with Pd/C for formic acid electrooxidation.
The support of C@WC core-shell structure is prepared with activated carbon as carbon source, in situ generation tungsten carbide coating on the surface of carbon material. TEM results confirm that the prepared of C@WC is core-shell structure. The composition of the shell is mainly WC containing a small amount of W. BET specific surface measurement results show that the specific surface area of C@WC is smaller than that of XC-72R, but with more of the mesoporous structure. The electrochemical surface area of Pd/C@WC is 65.47 m2/g. The Pd/C@WC catalyst electrode is more active for formic acid oxidation than Pd/C. The peak current density on Pd/C@WC is 0.222 A/cm2 which is about 0.128 A/cm2 higher than that on Pd/C. The multiple cyclic voltammograms results show that Pd/C@WC catalyst electrode has higher activity and stability compared with Pd/C for formic acid electrooxidation.
2014, 31(10): 1234-1236
doi: 10.3724/SP.J.1095.2014.40068
Abstract:
The UV shielding property of TiO2 pigments was investigated via the photodecomposition of hydrogen peroxide in aqueous medium. Based on the oxygen evolution kinetics, a series of pigments can show different UV shielding properties directly and effectively under UV irradiation(mainly 365 nm). This method is simple, fast and reproducible, and it may have potential applications in industrial production and practical useage.
The UV shielding property of TiO2 pigments was investigated via the photodecomposition of hydrogen peroxide in aqueous medium. Based on the oxygen evolution kinetics, a series of pigments can show different UV shielding properties directly and effectively under UV irradiation(mainly 365 nm). This method is simple, fast and reproducible, and it may have potential applications in industrial production and practical useage.
