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2015 Volume 31 Issue 12
2015, (12): 2279-2284
doi: 10.11862/CJIC.2015.308
Abstract:
The novel phosphors, Bi3+ and Eu3+ co-doped CaSb2O6 were obtained by co-precipitation technique followed by heat-treatment at 1 200 ℃ for 4 h. Their properties were investigated in detail. The phosphor has an average size of around 100~600 nm with hexagon round pie-like shape. It was found that the luminescence of Eu3+ ions in the CaSb2O6 could be efficiently sensitized by co-doping of Bi3+ ions involving energy transfer from Bi3+ to Eu3+. The 5D0→7F0 transition emission of Eu3+ was enhanced by a factor of ten when the Bi3+ content was 0.5% as compared to that of the sample without Bi3+ doped. Typically, it was observed that the CIE chromaticity coodinates varying from blue to white-light and eventually to red light could be achieved by tuning the relative ratio of Bi3+/Eu3+ in CaSb2O6:Bi3+, Eu3+. Hence, these results indicate that CaSb2O6:Bi3+, Eu3+ phosphors can serve as a potential application material for phosphor-converted white-light UV-LEDs.
The novel phosphors, Bi3+ and Eu3+ co-doped CaSb2O6 were obtained by co-precipitation technique followed by heat-treatment at 1 200 ℃ for 4 h. Their properties were investigated in detail. The phosphor has an average size of around 100~600 nm with hexagon round pie-like shape. It was found that the luminescence of Eu3+ ions in the CaSb2O6 could be efficiently sensitized by co-doping of Bi3+ ions involving energy transfer from Bi3+ to Eu3+. The 5D0→7F0 transition emission of Eu3+ was enhanced by a factor of ten when the Bi3+ content was 0.5% as compared to that of the sample without Bi3+ doped. Typically, it was observed that the CIE chromaticity coodinates varying from blue to white-light and eventually to red light could be achieved by tuning the relative ratio of Bi3+/Eu3+ in CaSb2O6:Bi3+, Eu3+. Hence, these results indicate that CaSb2O6:Bi3+, Eu3+ phosphors can serve as a potential application material for phosphor-converted white-light UV-LEDs.
2015, (12): 2285-2290
doi: 10.11862/CJIC.2015.300
Abstract:
A cyclometallated IrⅢ-μ-chloro-bridged dimer was synthesized by the reaction of a trifluoroacetylphenyl quinoline derivative and IrCl3. Then bicyclometalated iridium complex Ir(tfapq)2pic was synthesized by the reaction between dimer and picolinic acid. Ir(tfapq)2pic emitted a strong phosphorescence centered at 584 nm in a CH2Cl2 solution. Its lifetime is 1.211 μs and quantum yield is approximately 0.846 in a CH2Cl2 solution. Compared with the unmodified iridium complex, Ir(tfapq)2pic have a blue shift emission wavelength, sharp peak, higher quantum yield and shorter lifetime. The HOMO energy level is -5.405 eV and LUMO is -3.277 eV, which both lower than that of unmodified iridium complex and the greater energy band. The 10% weight loss temperature of Ir(tfapq)2pic is 301 ℃, which 50 ℃ higer than that of unmodified iridium complex. The organic light-emitting device based on Ir(tfapq)2pic (2wt% doped in PVK-PBD film) exhibits the best efficiency. It's peak electrophosphorescence wavelength is 594 nm. Its maximum external quantum efficiency is 12.65% and the corresponding efficiency is 22.14 cd·A-1. The maximum luminance is 8 571 cd·m-2. The turn-on voltage is 7.3 V with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.58, 0.40).
A cyclometallated IrⅢ-μ-chloro-bridged dimer was synthesized by the reaction of a trifluoroacetylphenyl quinoline derivative and IrCl3. Then bicyclometalated iridium complex Ir(tfapq)2pic was synthesized by the reaction between dimer and picolinic acid. Ir(tfapq)2pic emitted a strong phosphorescence centered at 584 nm in a CH2Cl2 solution. Its lifetime is 1.211 μs and quantum yield is approximately 0.846 in a CH2Cl2 solution. Compared with the unmodified iridium complex, Ir(tfapq)2pic have a blue shift emission wavelength, sharp peak, higher quantum yield and shorter lifetime. The HOMO energy level is -5.405 eV and LUMO is -3.277 eV, which both lower than that of unmodified iridium complex and the greater energy band. The 10% weight loss temperature of Ir(tfapq)2pic is 301 ℃, which 50 ℃ higer than that of unmodified iridium complex. The organic light-emitting device based on Ir(tfapq)2pic (2wt% doped in PVK-PBD film) exhibits the best efficiency. It's peak electrophosphorescence wavelength is 594 nm. Its maximum external quantum efficiency is 12.65% and the corresponding efficiency is 22.14 cd·A-1. The maximum luminance is 8 571 cd·m-2. The turn-on voltage is 7.3 V with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.58, 0.40).
2015, (12): 2291-2297
doi: 10.11862/CJIC.2015.304
Abstract:
One new alkene complexe of silver(Ⅰ), [AgL(NO3)]n (1), (L=4-allyl-2-methoxyphenyl nicotinate) has been prepared by self-assembly of AgNO3 with 4-allyl-2-methoxyphenyl nicotinate (L) in THF/H2O system. The structures of compounds L and 1 are determined by X-ray diffraction analysis. The crystals of the two compounds belong to the monoclinic space group. Compound L is connected to form a dimer, 2D layer sequentially by the weak C-H…O hydrogen bonds. The structure of 1 consists of 1D left-handed helical chains of [AgL]∞ in which the allyl arms and N atoms are coordinated to silver atoms, and right-handed helical chains of [AgNO3]∞ connecting through the Ag-O weak interactions. Two kinds of helices are connected in …ABAB… fashion to form a 2D achiral layer. Finally, the resulted 2D net extents to the 3D supramolecular architecture by the weak C-H…O interactions. In addition, the photoluminescence of L and 1 has been investigated in detail.
One new alkene complexe of silver(Ⅰ), [AgL(NO3)]n (1), (L=4-allyl-2-methoxyphenyl nicotinate) has been prepared by self-assembly of AgNO3 with 4-allyl-2-methoxyphenyl nicotinate (L) in THF/H2O system. The structures of compounds L and 1 are determined by X-ray diffraction analysis. The crystals of the two compounds belong to the monoclinic space group. Compound L is connected to form a dimer, 2D layer sequentially by the weak C-H…O hydrogen bonds. The structure of 1 consists of 1D left-handed helical chains of [AgL]∞ in which the allyl arms and N atoms are coordinated to silver atoms, and right-handed helical chains of [AgNO3]∞ connecting through the Ag-O weak interactions. Two kinds of helices are connected in …ABAB… fashion to form a 2D achiral layer. Finally, the resulted 2D net extents to the 3D supramolecular architecture by the weak C-H…O interactions. In addition, the photoluminescence of L and 1 has been investigated in detail.
2015, (12): 2298-2304
doi: 10.11862/CJIC.2015.317
Abstract:
Concave dendritic PtCu bimetallic nanocatalysts (PtCu NCDs) was prepared by one-step method in a Teflon-lined stainless steel autoclave with o-phenylenediamine as surface active agent. In the reaction system, o-phenylenediamine plays an important role in initiating, promoting and guiding replacement reaction. The PtCu NCDs exhibited exceptionally high activity and strong poisoning resistance in methanol oxidation reaction (MOR). The mass activity of PtCu NCDs (0.53 A·mg-1 Pt) was 2.04 times higher than that of the commercial Pt/C catalysts (0.26 A·mg-1 Pt) in MOR. The specific activity of PtCu NCDs (1.07 mA·cm-2) was 1.95 times higher than that of the commercial Pt/C catalysts (0.55 mA·cm-2). Moreover, PtCu NCDs (2.76) showed a higher ratio of If/Ib than the commercial Pt/C catalysts (1.02). The enhanced catalytic activity could be owed to the unique concave dendritic morphology of the bimetallic nanoparticles.
Concave dendritic PtCu bimetallic nanocatalysts (PtCu NCDs) was prepared by one-step method in a Teflon-lined stainless steel autoclave with o-phenylenediamine as surface active agent. In the reaction system, o-phenylenediamine plays an important role in initiating, promoting and guiding replacement reaction. The PtCu NCDs exhibited exceptionally high activity and strong poisoning resistance in methanol oxidation reaction (MOR). The mass activity of PtCu NCDs (0.53 A·mg-1 Pt) was 2.04 times higher than that of the commercial Pt/C catalysts (0.26 A·mg-1 Pt) in MOR. The specific activity of PtCu NCDs (1.07 mA·cm-2) was 1.95 times higher than that of the commercial Pt/C catalysts (0.55 mA·cm-2). Moreover, PtCu NCDs (2.76) showed a higher ratio of If/Ib than the commercial Pt/C catalysts (1.02). The enhanced catalytic activity could be owed to the unique concave dendritic morphology of the bimetallic nanoparticles.
2015, (12): 2305-2314
doi: 10.11862/CJIC.2015.316
Abstract:
Synthesized 4-mercaptobenzoic acid functionalized nano-gold particles and poly(vinylpyridine) overlapped nanogold-particles, were used as enzyme carriers to prepare two kinds of novel enzyme-based electrodes, respectively. Two prototypes of enzyme-based fuel cells were fabricated on the basis of previously described electrodes. Morphology of matrix with immobilized enzymes, influences of interaction between enzyme molecules and carriers on spectrometric characteristics of electrode surface anchored enzyme molecules, direct electron transfer dynamics between enzyme active centers and electrodes and catalytic function in substrate involved reaction, were investigated by the means of electrochemical method together with such techniques as ultra-violet/visible spectrometry(UV-Vis) and transmission electron microscope(TEM). Energy out-put performances for two kinds of fabricated enzyme-based fuel cells were evaluated and compared systematically. Results from test indicated 4-mercaptobenzoic acid surface-tailored nano-gold particles with enzymes modified electrodes displayed direct electron transfer between enzyme active sites and electrode, revealing favorable catalytic effect on glucose electro-oxidation and oxygen electro-reduction(catalytic reaction onset potential for glucose oxidationn and oxygen reduction: -0.03 and 0.96 V, turn-over frequency of substrates: 1.3 and 0.5 s-1, respectively). Reproducibility, long-term usability, acid/base endurance and thermal stability in catalytic function of previously mentioned electrode were preferable. Catalytic effect in substrate-related reaction of enzyme-based electrode increased with the thickness of self-assembled immobilized enzyme layers until approaching to maximal catalytic current. Test on performance of fuel cell showed open circuit voltage(OCV, 0.88 V), maximal out-put energy density(864.0 μW·cm-2) and excellent long-term stability(retaining above 80% of optimal energy out-put after storage for 3 weeks).
Synthesized 4-mercaptobenzoic acid functionalized nano-gold particles and poly(vinylpyridine) overlapped nanogold-particles, were used as enzyme carriers to prepare two kinds of novel enzyme-based electrodes, respectively. Two prototypes of enzyme-based fuel cells were fabricated on the basis of previously described electrodes. Morphology of matrix with immobilized enzymes, influences of interaction between enzyme molecules and carriers on spectrometric characteristics of electrode surface anchored enzyme molecules, direct electron transfer dynamics between enzyme active centers and electrodes and catalytic function in substrate involved reaction, were investigated by the means of electrochemical method together with such techniques as ultra-violet/visible spectrometry(UV-Vis) and transmission electron microscope(TEM). Energy out-put performances for two kinds of fabricated enzyme-based fuel cells were evaluated and compared systematically. Results from test indicated 4-mercaptobenzoic acid surface-tailored nano-gold particles with enzymes modified electrodes displayed direct electron transfer between enzyme active sites and electrode, revealing favorable catalytic effect on glucose electro-oxidation and oxygen electro-reduction(catalytic reaction onset potential for glucose oxidationn and oxygen reduction: -0.03 and 0.96 V, turn-over frequency of substrates: 1.3 and 0.5 s-1, respectively). Reproducibility, long-term usability, acid/base endurance and thermal stability in catalytic function of previously mentioned electrode were preferable. Catalytic effect in substrate-related reaction of enzyme-based electrode increased with the thickness of self-assembled immobilized enzyme layers until approaching to maximal catalytic current. Test on performance of fuel cell showed open circuit voltage(OCV, 0.88 V), maximal out-put energy density(864.0 μW·cm-2) and excellent long-term stability(retaining above 80% of optimal energy out-put after storage for 3 weeks).
Effects of Acid Treatment on Pore Structure and Oxidation Carbonylation Performance of CuY Catalysts
2015, (12): 2315-2323
doi: 10.11862/CJIC.2015.313
Abstract:
The NaY zeolite with nSi/nAl=2.65 was treated by oxalic acid aqueous solutions and used as supports to prepare CuY catalysts by liquid ion exchange for oxidative carbonylation of methanol to dimethyl carbonate (DMC) in atmospheres condition. The NaY zeolites and their corresponding CuY catalysts were characterized intensively by N2 adsorption-desorption, TEM, XRD, 29Si MAS NMR, NH3-TPD, Py-FTIR and H2-TPR. The results revealed that framework aluminum was leached out by acid, resulting in increase of the framework nSi/nAl ratio, decrease of the relative crystallinity, and formation of mesopores which are favor for diffusion of the products molecules and significantly affect the catalytic activity. Compared with the untreated sample, CuY catalysts treated by 4 h, 0.2 mol·L-1 oxalic acid exhibited higher catalytic performance with the increased space-time yield to DMC and conversion of methanol of 184.9 mg·g-1·h-1 and 10.2% from 103.6 mg·g-1 ·h-1 and 6.3% respectively. It is found the formed mesopores in CuY catalyst enhance the accessibility of Cu active sites by reactants and the diffusion of reactants and products molecules.
The NaY zeolite with nSi/nAl=2.65 was treated by oxalic acid aqueous solutions and used as supports to prepare CuY catalysts by liquid ion exchange for oxidative carbonylation of methanol to dimethyl carbonate (DMC) in atmospheres condition. The NaY zeolites and their corresponding CuY catalysts were characterized intensively by N2 adsorption-desorption, TEM, XRD, 29Si MAS NMR, NH3-TPD, Py-FTIR and H2-TPR. The results revealed that framework aluminum was leached out by acid, resulting in increase of the framework nSi/nAl ratio, decrease of the relative crystallinity, and formation of mesopores which are favor for diffusion of the products molecules and significantly affect the catalytic activity. Compared with the untreated sample, CuY catalysts treated by 4 h, 0.2 mol·L-1 oxalic acid exhibited higher catalytic performance with the increased space-time yield to DMC and conversion of methanol of 184.9 mg·g-1·h-1 and 10.2% from 103.6 mg·g-1 ·h-1 and 6.3% respectively. It is found the formed mesopores in CuY catalyst enhance the accessibility of Cu active sites by reactants and the diffusion of reactants and products molecules.
2015, (12): 2324-2330
doi: 10.11862/CJIC.2015.314
Abstract:
MIL-101(Cr) supported Pt nanoparticles (Pt/MIL-101(Cr)) catalyst was prepared by a facile impregna-tion method and used as an efficient catalyst for selective hydrogenation of cinnamaldehyde (CAL). The results of XRD, TEM and N2 adsorption and catalytic evaluation showed that Pt loadings greatly influenced the size of the supported nanoparticles on MIL-101(Cr) and the selectivity to cinnamyl alcohol (COL). Pt/MIL-101(Cr) catalyst with a low Pt loading (1.0%) exhibited much higher catalytic activity and COL selectivity in the selective hydrogenation of CAL as compared with Pt nanoparticles supported on other MOFs or inorganic supports, and its activity and selectivity to COL can reach 96.5% and 86.2% under optimized reaction conditions, respectively. The prepared Pt/MIL-101(Cr) catalyst is stable and can be reused at least five times without significant loss in the activity and selectivity. The excellent catalytic performance of Pt/MIL-101(Cr) is greatly related with the unique structure and surface property of MIL-101(Cr) support.
MIL-101(Cr) supported Pt nanoparticles (Pt/MIL-101(Cr)) catalyst was prepared by a facile impregna-tion method and used as an efficient catalyst for selective hydrogenation of cinnamaldehyde (CAL). The results of XRD, TEM and N2 adsorption and catalytic evaluation showed that Pt loadings greatly influenced the size of the supported nanoparticles on MIL-101(Cr) and the selectivity to cinnamyl alcohol (COL). Pt/MIL-101(Cr) catalyst with a low Pt loading (1.0%) exhibited much higher catalytic activity and COL selectivity in the selective hydrogenation of CAL as compared with Pt nanoparticles supported on other MOFs or inorganic supports, and its activity and selectivity to COL can reach 96.5% and 86.2% under optimized reaction conditions, respectively. The prepared Pt/MIL-101(Cr) catalyst is stable and can be reused at least five times without significant loss in the activity and selectivity. The excellent catalytic performance of Pt/MIL-101(Cr) is greatly related with the unique structure and surface property of MIL-101(Cr) support.
2015, (12): 2331-2336
doi: 10.11862/CJIC.2015.306
Abstract:
NiCo2S4 thin films have been successfully prepared by pulsed laser deposition. The structural, electrochemical properties and reaction mechanism of the NiCo2S4 thin film anodes for lithium ion batteries have been investigated by transmission electron microscopy (TEM), selected-area electron diffraction measurements (SAED), the charge/discharge measurements and cyclic voltammetry (CV). The charge/discharge results suggested that in the range of 0~3.0 V(vs Li+/Li), the reversible discharge capacity was 698 mAh·g-1 at a current density of 3 μA·cm-2. After 200 cycles, the discharge capacity was 365 mAh·g-1. Multistep reactions are revealed by the CV data of NiCo2S4 thin films. Ex situ TEM results showed that NiCo2S4 could react with Li to form Li2S, Co and Ni during initial discharging and NiS and CoS formed upon charging. The reversible electrochemical reacting occurred between NiS, CoS and Li2S, Co, Ni during the following cycles. NiCo2S4 was believed to be a promising anode material for rechargeable lithium batteries due to its good cycle performance.
NiCo2S4 thin films have been successfully prepared by pulsed laser deposition. The structural, electrochemical properties and reaction mechanism of the NiCo2S4 thin film anodes for lithium ion batteries have been investigated by transmission electron microscopy (TEM), selected-area electron diffraction measurements (SAED), the charge/discharge measurements and cyclic voltammetry (CV). The charge/discharge results suggested that in the range of 0~3.0 V(vs Li+/Li), the reversible discharge capacity was 698 mAh·g-1 at a current density of 3 μA·cm-2. After 200 cycles, the discharge capacity was 365 mAh·g-1. Multistep reactions are revealed by the CV data of NiCo2S4 thin films. Ex situ TEM results showed that NiCo2S4 could react with Li to form Li2S, Co and Ni during initial discharging and NiS and CoS formed upon charging. The reversible electrochemical reacting occurred between NiS, CoS and Li2S, Co, Ni during the following cycles. NiCo2S4 was believed to be a promising anode material for rechargeable lithium batteries due to its good cycle performance.
2015, (12): 2337-2342
doi: 10.11862/CJIC.2015.311
Abstract:
Two new metal-organic coordination polymers {[MnL]·0.5H2O}n (1),{[CaL(H2O)2]·H2O}n (2) (H2L=5-(4-(2,6-di(pyrazin-2-yl)pyridin-4-yl)phenoxy)isophthalic acid) have been synthesized under solvothermal reaction and characterized by single crystal X-ray diffraction analysis. 1 features a novel 3D supramolecular network built by different monochiral sheets with (3,3)-connected 2D net. 2 displays a 1D inorganic-chain linked by carboxylate oxygen atoms of L2- with Ca(Ⅱ) ions. Thermogravimetric analyses (TGA) have been measured for 1 and 2. Luminescent properties of 2 were investigated.
Two new metal-organic coordination polymers {[MnL]·0.5H2O}n (1),{[CaL(H2O)2]·H2O}n (2) (H2L=5-(4-(2,6-di(pyrazin-2-yl)pyridin-4-yl)phenoxy)isophthalic acid) have been synthesized under solvothermal reaction and characterized by single crystal X-ray diffraction analysis. 1 features a novel 3D supramolecular network built by different monochiral sheets with (3,3)-connected 2D net. 2 displays a 1D inorganic-chain linked by carboxylate oxygen atoms of L2- with Ca(Ⅱ) ions. Thermogravimetric analyses (TGA) have been measured for 1 and 2. Luminescent properties of 2 were investigated.
2015, (12): 2343-2348
doi: 10.11862/CJIC.2015.293
Abstract:
g-C3N4 and In2O3:Sn(ITO) photocatalysts were synthesized by low-temperature calcined method. A little nanosized ITO as an effective cocatalyst was loaded onto g-C3N4 particle surface by electrostatic attraction. The photocatalytic activity of ITO/g-C3N4 was performed by its H2 evolution performance under uv-vis irradiation while alcohol was used as a sacrificial agent, and the photocatalyst was characterized by XRD, SEM, TEM and UV-Vis absorption spectrum. The results showed that the photocatalytic activity of ITO/g-C3N4 was superior to that of pure g-C3N4, and loaded ITO can improve the interfacial electron transfer and the H2 evolution. When the amount of loaded ITO was 4%(wt), the stable average hydrogen evolution rate was about 350 μmol·g-1·h-1.
g-C3N4 and In2O3:Sn(ITO) photocatalysts were synthesized by low-temperature calcined method. A little nanosized ITO as an effective cocatalyst was loaded onto g-C3N4 particle surface by electrostatic attraction. The photocatalytic activity of ITO/g-C3N4 was performed by its H2 evolution performance under uv-vis irradiation while alcohol was used as a sacrificial agent, and the photocatalyst was characterized by XRD, SEM, TEM and UV-Vis absorption spectrum. The results showed that the photocatalytic activity of ITO/g-C3N4 was superior to that of pure g-C3N4, and loaded ITO can improve the interfacial electron transfer and the H2 evolution. When the amount of loaded ITO was 4%(wt), the stable average hydrogen evolution rate was about 350 μmol·g-1·h-1.
2015, (12): 2349-2357
doi: 10.11862/CJIC.2015.312
Abstract:
The crystal structures of hexa-carbonyl-di-iron complex with ferratetraphenyl cyclopentadiene ring (μ2, η4-C4Ph4)Fe2(CO)6 (1) and tetraphenyl substituted cyclopentadienone ligand (Ph4C4CO) (2) were characterized by spectroscopic determination and X-ray single crystal diffraction technique. The decomposition products and process of ferrole complex 1 were studied by FTIR, using sun light and xenon lamp with four filters as light source, respectively. The results show the light decomposition rate of ferrole complex 1 relates to light source and wavelength. The decomposition rate of sun light source is the fastest, and the decomposition rate of whole wavelength (320~780 nm) is correspondingly faster than that of other wavelengths under irradiation of the same xenon lamp. Ligand 2 is the main product from three decomposition reactions of ferrole complex 1 in the presence of light, heat and Br2 in acetic acid, respectively.
The crystal structures of hexa-carbonyl-di-iron complex with ferratetraphenyl cyclopentadiene ring (μ2, η4-C4Ph4)Fe2(CO)6 (1) and tetraphenyl substituted cyclopentadienone ligand (Ph4C4CO) (2) were characterized by spectroscopic determination and X-ray single crystal diffraction technique. The decomposition products and process of ferrole complex 1 were studied by FTIR, using sun light and xenon lamp with four filters as light source, respectively. The results show the light decomposition rate of ferrole complex 1 relates to light source and wavelength. The decomposition rate of sun light source is the fastest, and the decomposition rate of whole wavelength (320~780 nm) is correspondingly faster than that of other wavelengths under irradiation of the same xenon lamp. Ligand 2 is the main product from three decomposition reactions of ferrole complex 1 in the presence of light, heat and Br2 in acetic acid, respectively.
2015, (12): 2358-2364
doi: 10.11862/CJIC.2015.310
Abstract:
Highly ordered mesoporous molecular sieve MCM-48 with Ia3d cubic structure was hydrothermally synthesized using new surfactant cetyltrimethylammonium tosylate (CTATos) as template via phase transformation (PT). Structural study by small angle X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and nitrogen adsorption-desorption shows the time-dependent structural change in M41S mesoporous silica from MCM-41 to MCM-48 and MCM-50. The driving force for this transformation seems to be an increase of the local effective surfactant packing parameter (g), which resulted from the leaching of surfactant counter anions (Tos-) in the pore with the prolongation of the reaction time. One-dimensional solid state 29Si NMR spectra, X-ray diffraction patterns, and infrared spectra show the progression of molecular organization in the self-assembled mesophases from structures with initially amorphous silica networks into sheets with very high degrees of atomic order when the phase transformation is happening. The finally obtained self-assembled lamellar silica-surfactant mesophase composites with crystal-like ordering in the silica frameworks can be an ideal precursor to fabricate the three-dimensional microporous zeolites with the expanded pore size.
Highly ordered mesoporous molecular sieve MCM-48 with Ia3d cubic structure was hydrothermally synthesized using new surfactant cetyltrimethylammonium tosylate (CTATos) as template via phase transformation (PT). Structural study by small angle X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and nitrogen adsorption-desorption shows the time-dependent structural change in M41S mesoporous silica from MCM-41 to MCM-48 and MCM-50. The driving force for this transformation seems to be an increase of the local effective surfactant packing parameter (g), which resulted from the leaching of surfactant counter anions (Tos-) in the pore with the prolongation of the reaction time. One-dimensional solid state 29Si NMR spectra, X-ray diffraction patterns, and infrared spectra show the progression of molecular organization in the self-assembled mesophases from structures with initially amorphous silica networks into sheets with very high degrees of atomic order when the phase transformation is happening. The finally obtained self-assembled lamellar silica-surfactant mesophase composites with crystal-like ordering in the silica frameworks can be an ideal precursor to fabricate the three-dimensional microporous zeolites with the expanded pore size.
2015, (12): 2365-2372
doi: 10.11862/CJIC.2015.301
Abstract:
A hybrid materials of Fe3O4-DBI-PEG-ferulic acid (DBI=3,4-bihydroxy benzaldehyde, PEG= polyethylene glycol) were prepared by the method of grafting. The materials were characterized by IR, 1H NMR, TG, SEM, TEM,VSM and particle size tests, which showed that the ferulic acid was grafted on the surface of Fe3O4 nano-oxides which was modified by DBI-PEG. Meanwhile, the hybrid materials are dissoluble in water (solubility> 10 mg·mL-1)and with paramagnet. The anticoagulant properties of ferulic acid and the hybrid materials were tested by coagulation time (CT), recalcification time (RT), activated partial thromboplastin time (APTT), and prothrombin time (PT). The results indicated that the hybrid materials have better anticoagulant action than that of ferulic acid.
A hybrid materials of Fe3O4-DBI-PEG-ferulic acid (DBI=3,4-bihydroxy benzaldehyde, PEG= polyethylene glycol) were prepared by the method of grafting. The materials were characterized by IR, 1H NMR, TG, SEM, TEM,VSM and particle size tests, which showed that the ferulic acid was grafted on the surface of Fe3O4 nano-oxides which was modified by DBI-PEG. Meanwhile, the hybrid materials are dissoluble in water (solubility> 10 mg·mL-1)and with paramagnet. The anticoagulant properties of ferulic acid and the hybrid materials were tested by coagulation time (CT), recalcification time (RT), activated partial thromboplastin time (APTT), and prothrombin time (PT). The results indicated that the hybrid materials have better anticoagulant action than that of ferulic acid.
2015, (12): 2373-2378
doi: 10.11862/CJIC.2015.302
Abstract:
Double-layer SiO2 encapsulated Fe3O4 composite was prepared by a modified Stober method. The structures and properties of the composite were characterized by TEM, XRD, VSM and N2 absorption-desorption experiment, and its dye absorption properties were also investigated. This material possesses a BET surface area of 308 m2·g-1 and saturation magnetization of 45.5 emu·g-1. When the rhodamine B (RhB) concentration increases from 25 mg·L-1 to 250 mg·L-1, the RhB saturated absorption capacity of this composite increases from 24.0 mg· g-1 to 112.4 mg·g-1. When the methyl blue (MB) concentration increases from 25 mg·L-1 to 500 mg·L-1, the MB saturated absorption capacity of this composite increases from 22.0 mg·g-1 to 235.1 mg·g-1. With the increasing of pH value, the RhB absorption capacity increases, while that value of MB has no obvious change. The temperature in range of 20~40 ℃ is in favor of dye absorption for the composite.
Double-layer SiO2 encapsulated Fe3O4 composite was prepared by a modified Stober method. The structures and properties of the composite were characterized by TEM, XRD, VSM and N2 absorption-desorption experiment, and its dye absorption properties were also investigated. This material possesses a BET surface area of 308 m2·g-1 and saturation magnetization of 45.5 emu·g-1. When the rhodamine B (RhB) concentration increases from 25 mg·L-1 to 250 mg·L-1, the RhB saturated absorption capacity of this composite increases from 24.0 mg· g-1 to 112.4 mg·g-1. When the methyl blue (MB) concentration increases from 25 mg·L-1 to 500 mg·L-1, the MB saturated absorption capacity of this composite increases from 22.0 mg·g-1 to 235.1 mg·g-1. With the increasing of pH value, the RhB absorption capacity increases, while that value of MB has no obvious change. The temperature in range of 20~40 ℃ is in favor of dye absorption for the composite.
2015, (12): 2379-2384
doi: 10.11862/CJIC.2015.309
Abstract:
SiC nanofibers were synthesized on the carbon fiber fabrics by chemical vapor reactions. The morphology, microstructure and crystallinity of SiC nanofibers were characterized by X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM) with energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM), respectively. Results indicated that the large quantity of SiC nanofibers can be sythesized on the carbon fibers. The different morphologis were observed for the SiC nanofibers synthesized at different temperatures, but the diameters was almost same, which is about 100~300 nm. Based on the synthesis process and the characterization results, the vapor-solid (VS) reaction process are dominant mechanism for the growth of SiC nanofibers.
SiC nanofibers were synthesized on the carbon fiber fabrics by chemical vapor reactions. The morphology, microstructure and crystallinity of SiC nanofibers were characterized by X-ray diffractometer (XRD), field emission scanning electron microscopy (FE-SEM) with energy dispersive spectrometer (EDS) and transmission electron microscopy (TEM), respectively. Results indicated that the large quantity of SiC nanofibers can be sythesized on the carbon fibers. The different morphologis were observed for the SiC nanofibers synthesized at different temperatures, but the diameters was almost same, which is about 100~300 nm. Based on the synthesis process and the characterization results, the vapor-solid (VS) reaction process are dominant mechanism for the growth of SiC nanofibers.
2015, (12): 2385-2392
doi: 10.11862/CJIC.2015.307
Abstract:
Two new 2D cadmium(Ⅱ) coordination polymers, [Cd2(FDCA)2(DMA)2(DMF)]n (1) and [Cd3(FDC)3(DMF)4(H2O)]n (2) (H2FDC=2,5-furandicarboxylic acid, DMA=N, N-dimethylacetamide, DMF=N, N-dimethylformamide), have been successfully synthesized under solvothermal conditions and characterized by elemental analysis, IR-spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. The results reveal that both complexes 1 and 2 form 2D net structures, which are further linked to form 3D supramolecular structures via intermolecular C-H…O hydrogen bonding interactions. In solid state, 1 and 2 emit the intensely indigotin photoluminescence (501 and 476 nm) at room temperature.
Two new 2D cadmium(Ⅱ) coordination polymers, [Cd2(FDCA)2(DMA)2(DMF)]n (1) and [Cd3(FDC)3(DMF)4(H2O)]n (2) (H2FDC=2,5-furandicarboxylic acid, DMA=N, N-dimethylacetamide, DMF=N, N-dimethylformamide), have been successfully synthesized under solvothermal conditions and characterized by elemental analysis, IR-spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. The results reveal that both complexes 1 and 2 form 2D net structures, which are further linked to form 3D supramolecular structures via intermolecular C-H…O hydrogen bonding interactions. In solid state, 1 and 2 emit the intensely indigotin photoluminescence (501 and 476 nm) at room temperature.
2015, (12): 2393-2400
doi: 10.11862/CJIC.2015.305
Abstract:
Two copper(Ⅰ) coordination polymers, {[Cu2(4-bpo)2(CH3CN)2(PPh3)2](BF4)2}n (1), {[Cu(4-bpo)(CH3CN)(dppe)0.5]BF4}n (2) (PPh3=triphenylphosphine, dppe=1,2-bis(diphenyl phosphino)ethane, 4-bpo=2,5-bis(4-pyridyl)-1,3,4-oxadiazole), have been synthesized and characterized by IR, 1H NMR, 19F NMR, 11B NMR, elemental analysis and X-ray crystal structure analysis. The structural analysis shows that complexes 1 and 2 consist of diverse and interesting 2D supramolecular structures formed by inter-chain interactions. For 1, π-stacking interactions result in the construction of 1D bilayer chain and 2D supramolecular network. Compound 2 exhibits a 1D ladder-like chain and a 1D+1D→2D/3D supramolecular structure formed by π-stacking interactions. Solid-state emission spectra of complexes 1 and 2 have been studied, displaying the existence of ILCT/MLCT excited states.
Two copper(Ⅰ) coordination polymers, {[Cu2(4-bpo)2(CH3CN)2(PPh3)2](BF4)2}n (1), {[Cu(4-bpo)(CH3CN)(dppe)0.5]BF4}n (2) (PPh3=triphenylphosphine, dppe=1,2-bis(diphenyl phosphino)ethane, 4-bpo=2,5-bis(4-pyridyl)-1,3,4-oxadiazole), have been synthesized and characterized by IR, 1H NMR, 19F NMR, 11B NMR, elemental analysis and X-ray crystal structure analysis. The structural analysis shows that complexes 1 and 2 consist of diverse and interesting 2D supramolecular structures formed by inter-chain interactions. For 1, π-stacking interactions result in the construction of 1D bilayer chain and 2D supramolecular network. Compound 2 exhibits a 1D ladder-like chain and a 1D+1D→2D/3D supramolecular structure formed by π-stacking interactions. Solid-state emission spectra of complexes 1 and 2 have been studied, displaying the existence of ILCT/MLCT excited states.
2015, (12): 2401-2410
doi: 10.11862/CJIC.2015.286
Abstract:
Li2FeSiO4@C/CNTs (LFS@C/CNTs) nanocomposite was synthesized by a sol-gel method. A triblock copolymer P123 was used as the direction agent for nanopores and carbon source, and carbon nanotubes were used as conductive wires to further increase the conductivity of the material. The resulting LFS@C/CNTs nanocomposite possesses not only a nanoporous sponge-like structure for improving Li-ions transport by means of liquid electrolyte, but also a 3D self-bridged conduction hybrid network consisted of amorphous carbon coating and graphitized CNTs for electron fast transport that ultimately improves the high rate capability and cycling performance. As a result, the porous LFS@C/CNTs nanocomposite compared with nanoporous LFS@C exhibits a remarkable improvement in high-rate capability. The LFS@C/CNTs nanocomposite with 4wt% of CNTs delivers a specific discharge capacity of approximately 182 mAh·g-1 at 0.1C in the voltage window of 1.5~4.5 V, and the specific discharge capacity at 10C after 70 cycles maintains at 117 mA·h·g-1, which is more than two times that of LFS@C (55 mAh·g-1) as a cathode material for high power lithium ion battery.
Li2FeSiO4@C/CNTs (LFS@C/CNTs) nanocomposite was synthesized by a sol-gel method. A triblock copolymer P123 was used as the direction agent for nanopores and carbon source, and carbon nanotubes were used as conductive wires to further increase the conductivity of the material. The resulting LFS@C/CNTs nanocomposite possesses not only a nanoporous sponge-like structure for improving Li-ions transport by means of liquid electrolyte, but also a 3D self-bridged conduction hybrid network consisted of amorphous carbon coating and graphitized CNTs for electron fast transport that ultimately improves the high rate capability and cycling performance. As a result, the porous LFS@C/CNTs nanocomposite compared with nanoporous LFS@C exhibits a remarkable improvement in high-rate capability. The LFS@C/CNTs nanocomposite with 4wt% of CNTs delivers a specific discharge capacity of approximately 182 mAh·g-1 at 0.1C in the voltage window of 1.5~4.5 V, and the specific discharge capacity at 10C after 70 cycles maintains at 117 mA·h·g-1, which is more than two times that of LFS@C (55 mAh·g-1) as a cathode material for high power lithium ion battery.
2015, (12): 2411-2417
doi: 10.11862/CJIC.2015.288
Abstract:
Hollow Cu2ZnSnS4 spheres were synthesized by a poly(ethylene glycol) (PEG) assisted solvothermal route, employing copper chloride, zinc nitrate, stannous chloride, and thiourea as precursors. The polyethylene glycol (PEG) acting as the template coordination agent plays an important role in the formation of the final product. The formation mechanism of the hollow Cu2ZnSnS4 spheres was also discussed. The microstructure and optical properties of the hollow spheres were characterized by X-ray diffraction (XRD), Raman spectrometer, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), selected area electron diffraction spectroscopy (SAED), and UV-Vis absorption spectroscopy. The results reveal that the hollow Cu2ZnSnS4 spheres are crystallized in the tetragonal structure with about 600 nm in size. The optical absorption data show band-gap energy (Eg) of 1.52 eV which is optimal for photovoltaic applications.
Hollow Cu2ZnSnS4 spheres were synthesized by a poly(ethylene glycol) (PEG) assisted solvothermal route, employing copper chloride, zinc nitrate, stannous chloride, and thiourea as precursors. The polyethylene glycol (PEG) acting as the template coordination agent plays an important role in the formation of the final product. The formation mechanism of the hollow Cu2ZnSnS4 spheres was also discussed. The microstructure and optical properties of the hollow spheres were characterized by X-ray diffraction (XRD), Raman spectrometer, field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), selected area electron diffraction spectroscopy (SAED), and UV-Vis absorption spectroscopy. The results reveal that the hollow Cu2ZnSnS4 spheres are crystallized in the tetragonal structure with about 600 nm in size. The optical absorption data show band-gap energy (Eg) of 1.52 eV which is optimal for photovoltaic applications.
2015, (12): 2418-2424
doi: 10.11862/CJIC.2015.292
Abstract:
Three complexes [(Cu)(L)(Cl)2](1), [(Zn)(L)(Cl)2](2) and {[(Cd)2(L)(I)4]}n(3) (L is derived from 2-acetyl pyridine and picolinamide hydrazone) have been synthesized and characterized by single-crystal X-ray diffraction, elemental analysis and IR spectroscopy. X-ray diffraction analysis results show that complexes 1 and 2 are isostructural. The coordination geometry of the metal ion in each complex is a distorted trigonal biyramid with three nitrogen atoms from the ligand L and two chloride anions. However, in complex 3, two adjacent five-coordinated Cd(Ⅱ) ion are connected by two bridged μ2-I- anions, resulting in the formation of one-dimensional chain along c axis. In addition, the thermal stability and luminescent properties of the complexes are also studied in detail.
Three complexes [(Cu)(L)(Cl)2](1), [(Zn)(L)(Cl)2](2) and {[(Cd)2(L)(I)4]}n(3) (L is derived from 2-acetyl pyridine and picolinamide hydrazone) have been synthesized and characterized by single-crystal X-ray diffraction, elemental analysis and IR spectroscopy. X-ray diffraction analysis results show that complexes 1 and 2 are isostructural. The coordination geometry of the metal ion in each complex is a distorted trigonal biyramid with three nitrogen atoms from the ligand L and two chloride anions. However, in complex 3, two adjacent five-coordinated Cd(Ⅱ) ion are connected by two bridged μ2-I- anions, resulting in the formation of one-dimensional chain along c axis. In addition, the thermal stability and luminescent properties of the complexes are also studied in detail.
2015, (12): 2425-2431
doi: 10.11862/CJIC.2015.315
Abstract:
Rechargeable lithium-ion batteries (LIBs) have become the dominant power source for portable devices. In search for new and better electrode materials for LIBs for future stationary storage, electronic devices and equipments, people have recently started to look over crystalline ion-exchange materials with open channels that facilitate fast lithium ion transportation through the porous network. Herein, the use of Li-exchanged titanosilicate Na-JDF-L1 with a layered structure as anode materials for LIBs was reported. It shows a discharge capacity of 364 mAh·g-1 after the 200th cycle with ca. 100% Coulombic efficiency and negligible loss of capacity, comparable with the lithium titanate anode. Furthermore, the incorporation of TiO2 in Li(Na)-JDF-L1 improves the electrochemical performance of the electrode with better initial Coulombic efficiency and higher rate performance.
Rechargeable lithium-ion batteries (LIBs) have become the dominant power source for portable devices. In search for new and better electrode materials for LIBs for future stationary storage, electronic devices and equipments, people have recently started to look over crystalline ion-exchange materials with open channels that facilitate fast lithium ion transportation through the porous network. Herein, the use of Li-exchanged titanosilicate Na-JDF-L1 with a layered structure as anode materials for LIBs was reported. It shows a discharge capacity of 364 mAh·g-1 after the 200th cycle with ca. 100% Coulombic efficiency and negligible loss of capacity, comparable with the lithium titanate anode. Furthermore, the incorporation of TiO2 in Li(Na)-JDF-L1 improves the electrochemical performance of the electrode with better initial Coulombic efficiency and higher rate performance.
