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2020 Volume 36 Issue 2
2020, 36(2): 201-209
doi: 10.11862/CJIC.2020.039
Abstract:
Solvothermal syntheses of benzimidazyl ligand(H2L) with zinc and nickel ions resulted in two monomeric complexes, [Ni(HL)(HCOO)(H2O)] (1) and[Zn(H2L)(H2O)2](NO3)2 (2). The two monomeric complexes are butterfly-shaped, which are further connected into 2D or 3D networks through intermolecular hydrogen bonds. The two monomers are stable in aqueous solution and slight soluble in water. Fluorescence measurements showed that complex 2 had strong fluorescence properties in both solid state and aqueous solutions. A further study shows that both metal ion Hg2+ and anion Cr2O72- have high fluorescence quenching effect on in aqueous solution of 2, indicating that 2 could be used as a highly selective and sensitive detection probe for Hg2+ and Cr2O72-.
Solvothermal syntheses of benzimidazyl ligand(H2L) with zinc and nickel ions resulted in two monomeric complexes, [Ni(HL)(HCOO)(H2O)] (1) and[Zn(H2L)(H2O)2](NO3)2 (2). The two monomeric complexes are butterfly-shaped, which are further connected into 2D or 3D networks through intermolecular hydrogen bonds. The two monomers are stable in aqueous solution and slight soluble in water. Fluorescence measurements showed that complex 2 had strong fluorescence properties in both solid state and aqueous solutions. A further study shows that both metal ion Hg2+ and anion Cr2O72- have high fluorescence quenching effect on in aqueous solution of 2, indicating that 2 could be used as a highly selective and sensitive detection probe for Hg2+ and Cr2O72-.
2020, 36(2): 210-216
doi: 10.11862/CJIC.2020.041
Abstract:
Fe(CO)5 was used as precursor to construct nano-sized carbonyl iron (CI) shell on carbon fiber (CF) surface by metal organic chemical vapor deposition (MOCVD). The morphology and microwave absorption properties of core-shell powders were controlled by changing deposition temperature. The structure and electromagnetic properties of the powders were characterized by X-ray diffractometer, scanning electron microscopy and vector network analyzer. The results show that the carbonyl iron particles deposited on the surface of CF "merge and fuse" with the increase of deposition temperature (210~240℃). At this time, CF-CI forms a complete core-shell structure with thin film coating. When the deposition temperature is too high (270℃), the morphology of carbonyl iron shell on the surface of CF will deteriorate. The thickness of CI shell on CF surface can be effectively controlled by adjusting deposition temperature at nanoscale, thus the electromagnetic properties of CF-CI core-shell particles can be adjusted. The core-shell morphology and microwave absorption properties were taken as indexes to determine the optimum deposition temperature of 240℃. With the electromagnetic parameters of the samples obtained at 240℃, the maximum absorbing bandwidth is 4.6 GHz (13.4~18 GHz) when the thickness of the coating is 0.9 mm, the minimum reflectivity is -21.5 dB when the thickness of the coating is 2.0 mm, and the absorption intensity is less than -10 dB among the whole 2~18 GHz when the thickness of the coating is 0.9~3.9 mm.
Fe(CO)5 was used as precursor to construct nano-sized carbonyl iron (CI) shell on carbon fiber (CF) surface by metal organic chemical vapor deposition (MOCVD). The morphology and microwave absorption properties of core-shell powders were controlled by changing deposition temperature. The structure and electromagnetic properties of the powders were characterized by X-ray diffractometer, scanning electron microscopy and vector network analyzer. The results show that the carbonyl iron particles deposited on the surface of CF "merge and fuse" with the increase of deposition temperature (210~240℃). At this time, CF-CI forms a complete core-shell structure with thin film coating. When the deposition temperature is too high (270℃), the morphology of carbonyl iron shell on the surface of CF will deteriorate. The thickness of CI shell on CF surface can be effectively controlled by adjusting deposition temperature at nanoscale, thus the electromagnetic properties of CF-CI core-shell particles can be adjusted. The core-shell morphology and microwave absorption properties were taken as indexes to determine the optimum deposition temperature of 240℃. With the electromagnetic parameters of the samples obtained at 240℃, the maximum absorbing bandwidth is 4.6 GHz (13.4~18 GHz) when the thickness of the coating is 0.9 mm, the minimum reflectivity is -21.5 dB when the thickness of the coating is 2.0 mm, and the absorption intensity is less than -10 dB among the whole 2~18 GHz when the thickness of the coating is 0.9~3.9 mm.
2020, 36(2): 217-225
doi: 10.11862/CJIC.2020.040
Abstract:
Using melamine and chloroplatinic acid (H2PtCl6·6H2O) as raw materials, graphite phase carbon nitride doped with different contents of Pt2+/Pt0 (Pt2+/Pt0-CN) was prepared by a simple one-step calcination method. Their morphologies, crystal structure, chemical compositions, surface area, optical and electrical physicochemical properties were characterized by scan microscopy, transmission electron microscopy, X ray powder diffraction, X ray photoelectron spectroscopy, N2 physical adsorption-desorption, UV-Visible diffuse reflectance spectra and photocurrent measurement. From the XPS analysis, the ratio of Pt0 and Pt2+ was around 1:7.26. Platinum particles were doped into the surface and body of the g-C3N4. Compared with g-C3N4, Pt2+/Pt0-CN composites showed much higher photocatalytic degradation activity than that of g-C3N4. With theory loading mass fraction of Pt2+/Pt0 (0.02%), the degradation rates of ciprofloxacin, rhodamine B, acid orangeⅡ, methyl orange and methylene blue were increased 43%, 64%, 39%, 42% and 52%, respectively. The doping of Pt2+/Pt0 into g-C3N4 can largely boost the surface area. At the same time, the light absorption of Pt2+/Pt0-CN composites was enhanced and the recombination of photogernerated holes (h+) and electrons (e-) was restrained.
Using melamine and chloroplatinic acid (H2PtCl6·6H2O) as raw materials, graphite phase carbon nitride doped with different contents of Pt2+/Pt0 (Pt2+/Pt0-CN) was prepared by a simple one-step calcination method. Their morphologies, crystal structure, chemical compositions, surface area, optical and electrical physicochemical properties were characterized by scan microscopy, transmission electron microscopy, X ray powder diffraction, X ray photoelectron spectroscopy, N2 physical adsorption-desorption, UV-Visible diffuse reflectance spectra and photocurrent measurement. From the XPS analysis, the ratio of Pt0 and Pt2+ was around 1:7.26. Platinum particles were doped into the surface and body of the g-C3N4. Compared with g-C3N4, Pt2+/Pt0-CN composites showed much higher photocatalytic degradation activity than that of g-C3N4. With theory loading mass fraction of Pt2+/Pt0 (0.02%), the degradation rates of ciprofloxacin, rhodamine B, acid orangeⅡ, methyl orange and methylene blue were increased 43%, 64%, 39%, 42% and 52%, respectively. The doping of Pt2+/Pt0 into g-C3N4 can largely boost the surface area. At the same time, the light absorption of Pt2+/Pt0-CN composites was enhanced and the recombination of photogernerated holes (h+) and electrons (e-) was restrained.
2020, 36(2): 226-232
doi: 10.11862/CJIC.2020.035
Abstract:
Two metal complexes, [Zn(3-NBA)(trz)]n (1) and[Pb(3-NBA)(phen)2]NO3 (2), have been constructed through hydrothermal reaction using 3-nitrophthalic acid (3-NPAH2), phen (1, 10-phenanthroline) or 1, 2, 4-triazole (Htrz), and ZnSO4·7H2O or Pb(NO3)2. During the reaction, the 3-HNBA resulted from the in situ decarboxylation of 3-nitrophthalic acid, and the experimental results have been confirmed by the theoretical calculation. Complexes 1~2 have been characterized by IR spectra, PXRD, elemental analyses and thermogravimetric analyses. Single-crystal X-ray diffraction analyses reveal that complex 1 exhibits a two-dimensional (2D) layered structure, which packs through weak N-O…π interactions. Complex 2 has a monomeric structure, which is assembled to a three-dimensional (3D) supramolecular structure through weak π…π interactions. Furthermore, the solid-state fluorescence of complexes 1~2 was recorded at room temperature.
Two metal complexes, [Zn(3-NBA)(trz)]n (1) and[Pb(3-NBA)(phen)2]NO3 (2), have been constructed through hydrothermal reaction using 3-nitrophthalic acid (3-NPAH2), phen (1, 10-phenanthroline) or 1, 2, 4-triazole (Htrz), and ZnSO4·7H2O or Pb(NO3)2. During the reaction, the 3-HNBA resulted from the in situ decarboxylation of 3-nitrophthalic acid, and the experimental results have been confirmed by the theoretical calculation. Complexes 1~2 have been characterized by IR spectra, PXRD, elemental analyses and thermogravimetric analyses. Single-crystal X-ray diffraction analyses reveal that complex 1 exhibits a two-dimensional (2D) layered structure, which packs through weak N-O…π interactions. Complex 2 has a monomeric structure, which is assembled to a three-dimensional (3D) supramolecular structure through weak π…π interactions. Furthermore, the solid-state fluorescence of complexes 1~2 was recorded at room temperature.
2020, 36(2): 233-240
doi: 10.11862/CJIC.2020.043
Abstract:
Bridged pyridine ligand 4-methyl-2, 6-bis(pyridin-3'-ylethynyl) aniline (L1) and an unreported ligand with smaller scale, 2, 6-bis(3'-pyridyl)-4-methylaniline (L2) were synthesized. Two complexes[Cu2(L1)(OAc)4]2 (1, OAc-=CH3CO2-) and {[Cu2(L2)(OAc)4]·2CH2Cl2·CH3CN}n (2) were obtained using L1 or L2 and cupric acetate monohydrate (Cu(OAc)2·H2O) in mixed organic solvent at room temperature. The complexes 1 and 2 were characterized by X-ray single crystal diffraction, IR and elemental analysis. The structural research reveals that both the complexes 1 and 2 contain the dinuclear copper cluster of {Cu2(OAc)4}, but complex 1 has a "2+2" planar macrocycle structure in which L1 coordinated with the dinuclear copper clusters in a U-configuration and complex 2 has 1D chain structure where L2 connected the adjacent dinuclears in a Z-configuration. The structural difference between the two complexes is due to the different scale of the ligands L1 and L2, demonstrating the effect of the ligand scale in structural regulation. The fluorescence property of these two complexes were investigated, and it was confirmed that the introduction of copper quenched the fluorescence emission. The experiment of photocatalytic degradation of methylene blue (MB) proved that the macrocycle complex 1 has better catalytic activity than complex 2 with 1D chain structure and both of them are better than cupric acetate.
Bridged pyridine ligand 4-methyl-2, 6-bis(pyridin-3'-ylethynyl) aniline (L1) and an unreported ligand with smaller scale, 2, 6-bis(3'-pyridyl)-4-methylaniline (L2) were synthesized. Two complexes[Cu2(L1)(OAc)4]2 (1, OAc-=CH3CO2-) and {[Cu2(L2)(OAc)4]·2CH2Cl2·CH3CN}n (2) were obtained using L1 or L2 and cupric acetate monohydrate (Cu(OAc)2·H2O) in mixed organic solvent at room temperature. The complexes 1 and 2 were characterized by X-ray single crystal diffraction, IR and elemental analysis. The structural research reveals that both the complexes 1 and 2 contain the dinuclear copper cluster of {Cu2(OAc)4}, but complex 1 has a "2+2" planar macrocycle structure in which L1 coordinated with the dinuclear copper clusters in a U-configuration and complex 2 has 1D chain structure where L2 connected the adjacent dinuclears in a Z-configuration. The structural difference between the two complexes is due to the different scale of the ligands L1 and L2, demonstrating the effect of the ligand scale in structural regulation. The fluorescence property of these two complexes were investigated, and it was confirmed that the introduction of copper quenched the fluorescence emission. The experiment of photocatalytic degradation of methylene blue (MB) proved that the macrocycle complex 1 has better catalytic activity than complex 2 with 1D chain structure and both of them are better than cupric acetate.
2020, 36(2): 241-252
doi: 10.11862/CJIC.2020.018
Abstract:
CuCo bimetallic nanoparticles were supported on few layer boron nitride nanosheets (BNNSs) prepared by polyvinylpyrrolidone (PVP)-assisted ion intercalation, and a highly dispersed copper-cobalt/boron nitride nanosheets (donated as CuCo/BNNSs) nanocatalyst with an average particle size of 2.7 nm was obtained with a method of co-reduction. The structure and morphology of the carrier and catalyst were characterized by atomic force microscope (AFM), X-ray diffraction (XRD), fourier transform infrared (FTIR), Raman spectra (Raman), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and high resolution transmission electron microscopy (HRTEM), and the catalytic performance of CuCo/BNNSs was studied. The results showed that Cu0.5Co0.5/BNNSs nanocatalysts exhibited high catalytic activity towards the hydrolysis of ammonia borane (AB, NH3BH3) at room temperature when pH value was 14 and the turn over frequency (TOF) reached 104.52 molH2·molmetal-1·min-1 due to the highly efficient quadruple synergistic effect between Cu, Co, BNNSs and OH-. Moreover, the CuCo/BNNSs nanocatalyst also had good stability and high catalytic activity was maintained after 6 cycles.
CuCo bimetallic nanoparticles were supported on few layer boron nitride nanosheets (BNNSs) prepared by polyvinylpyrrolidone (PVP)-assisted ion intercalation, and a highly dispersed copper-cobalt/boron nitride nanosheets (donated as CuCo/BNNSs) nanocatalyst with an average particle size of 2.7 nm was obtained with a method of co-reduction. The structure and morphology of the carrier and catalyst were characterized by atomic force microscope (AFM), X-ray diffraction (XRD), fourier transform infrared (FTIR), Raman spectra (Raman), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and high resolution transmission electron microscopy (HRTEM), and the catalytic performance of CuCo/BNNSs was studied. The results showed that Cu0.5Co0.5/BNNSs nanocatalysts exhibited high catalytic activity towards the hydrolysis of ammonia borane (AB, NH3BH3) at room temperature when pH value was 14 and the turn over frequency (TOF) reached 104.52 molH2·molmetal-1·min-1 due to the highly efficient quadruple synergistic effect between Cu, Co, BNNSs and OH-. Moreover, the CuCo/BNNSs nanocatalyst also had good stability and high catalytic activity was maintained after 6 cycles.
2020, 36(2): 253-260
doi: 10.11862/CJIC.2020.012
Abstract:
Ag3PO4 based-GO/Ag3PO4/Ni composite thin films were prepared by electrochemical co-deposition using a mixture of ammonium phosphate and graphene oxide aqueous suspension as electrolyte. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Raman and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) were employed to analyze the morphology, crystallinity and optical characteristics of the composite films. The results showed that the GO/Ag3PO4/Ni composite films prepared by the optimum process exhibited GO-coated surface morphology outside Ag3PO4 nanospheres with a diameter of about 100 nm. The strong charge interactions existed between GO sheets and Ag3PO4 nanospheres. As compared to Ag3PO4 nanospheres alone, the attachments of GO sheets led to a band gap narrowing and a strong absorbance in visible region. The photocatalytic (PC) activity and stability of the GO/Ag3PO4/Ni thin films were investigated by following the degradation of rhodamine B (RhB) under visible light irradiation. The PC mechanism of the composite films was explored by fluorescence spectroscopy and trapping agent method. Notably, the incorporation of GO sheets not only significantly enhanced the PC activity but also improved the structural stability of Ag3PO4. The efficiency of PC degradation of RhB under visible light irradiation 60 min was 1.32 times greater than that observed when a Ag3PO4/Ni thin film was used. GO/Ag3PO4/Ni thin films could be reused seven times without any significant decrease in the catalytic activity of the film. The excellent charge conductivity of GO and the positive synergistic effect between Ag3PO4 nanospheres and GO sheets are proposed to contribute to the improved PC properties of the composite films.
Ag3PO4 based-GO/Ag3PO4/Ni composite thin films were prepared by electrochemical co-deposition using a mixture of ammonium phosphate and graphene oxide aqueous suspension as electrolyte. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Raman and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) were employed to analyze the morphology, crystallinity and optical characteristics of the composite films. The results showed that the GO/Ag3PO4/Ni composite films prepared by the optimum process exhibited GO-coated surface morphology outside Ag3PO4 nanospheres with a diameter of about 100 nm. The strong charge interactions existed between GO sheets and Ag3PO4 nanospheres. As compared to Ag3PO4 nanospheres alone, the attachments of GO sheets led to a band gap narrowing and a strong absorbance in visible region. The photocatalytic (PC) activity and stability of the GO/Ag3PO4/Ni thin films were investigated by following the degradation of rhodamine B (RhB) under visible light irradiation. The PC mechanism of the composite films was explored by fluorescence spectroscopy and trapping agent method. Notably, the incorporation of GO sheets not only significantly enhanced the PC activity but also improved the structural stability of Ag3PO4. The efficiency of PC degradation of RhB under visible light irradiation 60 min was 1.32 times greater than that observed when a Ag3PO4/Ni thin film was used. GO/Ag3PO4/Ni thin films could be reused seven times without any significant decrease in the catalytic activity of the film. The excellent charge conductivity of GO and the positive synergistic effect between Ag3PO4 nanospheres and GO sheets are proposed to contribute to the improved PC properties of the composite films.
2020, 36(2): 261-268
doi: 10.11862/CJIC.2020.019
Abstract:
Graphitic carbon nitride (g-C3N4) was synthesized by thermal polymerization method using urea and dicyandiamide as raw materials. Then, g-C3N4 was treated at different temperatures by two post-heat treatment methods:direct secondary calcination and molten salt ionothermal post-heat treatment, respectively. As s results, different nitrogen-defected carbon nitride materials CN and CNS were obtained. The prepared samples were characterized and analyzed via X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectrum (UV-Vis DRS), transmission electron microscopy (TEM), and so on. The effect of different heat treatment temperatures and heating methods on the microstructure of catalysts were discussed. The photocatalytic properties of catalysts were tested by H2 production from water splitting under visible light irradiation. The results showed that ionothermal post-heat treatment method was more conductive to interlayer polymerization of g-C3N4 than direct calcination, and high crystallinity materials were obtained. Nitrogen defects were introduced into the in-plane heptazine polymerization accompanying the production of terminal cyano groups. The strong electron absorption of cyano could optimize the charge density distribution and enhanced the charge fluidity. In addition, molten salt heat treatment increased porosity and expanded the light absorption range of CNS samples. CNS-500 prepared under 500℃ ionothermal post-heat treatment exhibited excellent photocatalytic hydrogen evolution activity, which was 3.84 times as high as that of the catalyst prepared by direct post-heat treatment at the same temperature.
Graphitic carbon nitride (g-C3N4) was synthesized by thermal polymerization method using urea and dicyandiamide as raw materials. Then, g-C3N4 was treated at different temperatures by two post-heat treatment methods:direct secondary calcination and molten salt ionothermal post-heat treatment, respectively. As s results, different nitrogen-defected carbon nitride materials CN and CNS were obtained. The prepared samples were characterized and analyzed via X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectrum (UV-Vis DRS), transmission electron microscopy (TEM), and so on. The effect of different heat treatment temperatures and heating methods on the microstructure of catalysts were discussed. The photocatalytic properties of catalysts were tested by H2 production from water splitting under visible light irradiation. The results showed that ionothermal post-heat treatment method was more conductive to interlayer polymerization of g-C3N4 than direct calcination, and high crystallinity materials were obtained. Nitrogen defects were introduced into the in-plane heptazine polymerization accompanying the production of terminal cyano groups. The strong electron absorption of cyano could optimize the charge density distribution and enhanced the charge fluidity. In addition, molten salt heat treatment increased porosity and expanded the light absorption range of CNS samples. CNS-500 prepared under 500℃ ionothermal post-heat treatment exhibited excellent photocatalytic hydrogen evolution activity, which was 3.84 times as high as that of the catalyst prepared by direct post-heat treatment at the same temperature.
2020, 36(2): 269-275
doi: 10.11862/CJIC.2020.033
Abstract:
Quinone compound called pillar[5]quinone (P5Q) was chosen as cathode to explore lithium storage performance. Experimental data indicated that the initial capacity reached 431 mAh·g-1, displaying 100% utilization rate of active sites. Nevertheless, P5Q was easily dissolved when exposed to the electrolyte, which resulted in rapid decay of capacity. For addressing this issue, encapsulation method was employed. We chose CMK-3 as porous carbon material in this study for its uniform pores and moderate pore size. Herein, P5Q was filled into the holes of CMK-3, and then obtaining the P5Q/CMK-3 nanocomposites. The experiment results showed that the pouring method effectively slowed the dissolution of P5Q in electrolyte. After 100 cycles, the discharge capacity of P5Q/CMK-3 composites maintained at 300 mAh·g-1, the retention was as high as 71%, and coulombic efficiency was around 100% during the test period.
Quinone compound called pillar[5]quinone (P5Q) was chosen as cathode to explore lithium storage performance. Experimental data indicated that the initial capacity reached 431 mAh·g-1, displaying 100% utilization rate of active sites. Nevertheless, P5Q was easily dissolved when exposed to the electrolyte, which resulted in rapid decay of capacity. For addressing this issue, encapsulation method was employed. We chose CMK-3 as porous carbon material in this study for its uniform pores and moderate pore size. Herein, P5Q was filled into the holes of CMK-3, and then obtaining the P5Q/CMK-3 nanocomposites. The experiment results showed that the pouring method effectively slowed the dissolution of P5Q in electrolyte. After 100 cycles, the discharge capacity of P5Q/CMK-3 composites maintained at 300 mAh·g-1, the retention was as high as 71%, and coulombic efficiency was around 100% during the test period.
2020, 36(2): 276-282
doi: 10.11862/CJIC.2020.016
Abstract:
LaBO3:Eu3+ phosphors with different crystal phase were prepared by heat treatment precursor prepared by hydrothermal method. The structure, morphology and luminescence properties of the samples were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), infrared spectroscopy and fluorescence spectroscopy. The effects of boric acid dosage, heat treatment temperature, and initial solution pH of precursor on structure and luminescence properties of the samples were studied. The results of XRD showed that the phosphors with orthogonal structure, monoclinic structure and both phase mixed structure can be obtained. LaBO3 with pure orthogonal structure can be obtained by heating treatment at 700℃ for precursors synthesized with initial solution pH=8 and molar ratio of rare earth ions to boric acid of 1:3 and 1:4, respectively. It is convenient to obtained phosphors with orthogonal structure at proper boric acid dosage, higher heat treatment temperature and higher initial solution pH value. Infrared spectra showed that the change of initial solution pH and boric acid dosage effected the composition of precursor, and the heat treatment temperature effected the crystal phase transformation. SEM showed that particle size of LaBO3:Eu3+ phosphor decreased with the increase of initial solution pH, which were consistent with the results calculated from XRD. The excitation spectra of samples consisted of the broad band in a range of 200~350 nm and another weak narrow lines in a range of 350~450 nm, which were assigned to O2--Eu3+ charge transfer band and f-f transitions of Eu3+ ions, respectively. The emission spectra of samples consisted of sharp lines ranging from 500 to 750 nm, which are associated with the transitions from the excited 5D0-7FJ (J=1, 2, 3, 4) of Eu3+ ions. The main emission peak at 615 nm was due to the 5D0-7F2 transitions of Eu3+, the peak at 593 nm was attributed to 5D0-7F1 transitions of Eu3+. The excitation and emission intensities are related to the structure of the samples. LaBO3:Eu3+ with orthogonal structure has higher ultraviolet absorption and higher emission intensity with pure red light.
LaBO3:Eu3+ phosphors with different crystal phase were prepared by heat treatment precursor prepared by hydrothermal method. The structure, morphology and luminescence properties of the samples were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), infrared spectroscopy and fluorescence spectroscopy. The effects of boric acid dosage, heat treatment temperature, and initial solution pH of precursor on structure and luminescence properties of the samples were studied. The results of XRD showed that the phosphors with orthogonal structure, monoclinic structure and both phase mixed structure can be obtained. LaBO3 with pure orthogonal structure can be obtained by heating treatment at 700℃ for precursors synthesized with initial solution pH=8 and molar ratio of rare earth ions to boric acid of 1:3 and 1:4, respectively. It is convenient to obtained phosphors with orthogonal structure at proper boric acid dosage, higher heat treatment temperature and higher initial solution pH value. Infrared spectra showed that the change of initial solution pH and boric acid dosage effected the composition of precursor, and the heat treatment temperature effected the crystal phase transformation. SEM showed that particle size of LaBO3:Eu3+ phosphor decreased with the increase of initial solution pH, which were consistent with the results calculated from XRD. The excitation spectra of samples consisted of the broad band in a range of 200~350 nm and another weak narrow lines in a range of 350~450 nm, which were assigned to O2--Eu3+ charge transfer band and f-f transitions of Eu3+ ions, respectively. The emission spectra of samples consisted of sharp lines ranging from 500 to 750 nm, which are associated with the transitions from the excited 5D0-7FJ (J=1, 2, 3, 4) of Eu3+ ions. The main emission peak at 615 nm was due to the 5D0-7F2 transitions of Eu3+, the peak at 593 nm was attributed to 5D0-7F1 transitions of Eu3+. The excitation and emission intensities are related to the structure of the samples. LaBO3:Eu3+ with orthogonal structure has higher ultraviolet absorption and higher emission intensity with pure red light.
2020, 36(2): 283-288
doi: 10.11862/CJIC.2020.025
Abstract:
A series of the Fe3O4@PDA@PAMAM magnetic nano-adsorbed materials with different dopamine (DA) dosages were prepared by using self-made Fe3O4 as magnetic core materials and DA as surface modifier, then grafting with 2.0 G polyamide-amine (PAMAM) macromolecule. The composition, microstructure, magnetic properties and adsorption properties of heavy metal Cd(Ⅱ) ions were studied by X-ray diffractometer (XRD), infrared spectrometer (IR), vibrating sample magnetometer (VSM), transmission electron microscope (TEM) and inductively coupled plasma emission spectrometer (ICP-OES). The effect of DA dosages on the phase composition, microstructure, magnetic properties and adsorption properties of Fe3O4@PDA@PAMAM magnetic nano-adsorbed materials were researched as well. The results showed that Fe3O4@PDA@PAMAM magnetic nano-adsorbed materials were typical core-shell structure while the thickness of the shell increased with the increase of DA dosages, and the crystal forms of the materials all showed spinel structure. The saturation magnetization (Ms) of Fe3O4@PDA@PAMAM with different DA dosages decreased with the increase of DA dosages, which was smaller than that of Fe3O4. As the coercivity (Hc) and residual magnetization (Mr) of the materials were lower, the magnetic response characteristics of magnetic nano-adsorbed materials showed good recycling performance. The equilibrium adsorption capacity of Fe3O4@PDA@PAMAM magnetic nano-adsorbed materials for Cd(Ⅱ) ions increased firstly and then decreased with the increase of DA dosages. When the mass radio of Fe3O4 and DA was 8:4, the adsorption capacity of the prepared materials for Cd(Ⅱ) ions has a maximum of 165.13 mg·g-1.
A series of the Fe3O4@PDA@PAMAM magnetic nano-adsorbed materials with different dopamine (DA) dosages were prepared by using self-made Fe3O4 as magnetic core materials and DA as surface modifier, then grafting with 2.0 G polyamide-amine (PAMAM) macromolecule. The composition, microstructure, magnetic properties and adsorption properties of heavy metal Cd(Ⅱ) ions were studied by X-ray diffractometer (XRD), infrared spectrometer (IR), vibrating sample magnetometer (VSM), transmission electron microscope (TEM) and inductively coupled plasma emission spectrometer (ICP-OES). The effect of DA dosages on the phase composition, microstructure, magnetic properties and adsorption properties of Fe3O4@PDA@PAMAM magnetic nano-adsorbed materials were researched as well. The results showed that Fe3O4@PDA@PAMAM magnetic nano-adsorbed materials were typical core-shell structure while the thickness of the shell increased with the increase of DA dosages, and the crystal forms of the materials all showed spinel structure. The saturation magnetization (Ms) of Fe3O4@PDA@PAMAM with different DA dosages decreased with the increase of DA dosages, which was smaller than that of Fe3O4. As the coercivity (Hc) and residual magnetization (Mr) of the materials were lower, the magnetic response characteristics of magnetic nano-adsorbed materials showed good recycling performance. The equilibrium adsorption capacity of Fe3O4@PDA@PAMAM magnetic nano-adsorbed materials for Cd(Ⅱ) ions increased firstly and then decreased with the increase of DA dosages. When the mass radio of Fe3O4 and DA was 8:4, the adsorption capacity of the prepared materials for Cd(Ⅱ) ions has a maximum of 165.13 mg·g-1.
2020, 36(2): 289-294
doi: 10.11862/CJIC.2020.028
Abstract:
By effectively combining in-situ crystallization and solvent-free method, the ZSM-5 zeolite was synthesized by seed induction and optimal synthesis conditions in a green and efficient manner on the basis of kaolin as raw material without adding organic template agent and solvent. The optimal synthesis conditions for the synthesis of ZSM-5 was:nNa2O/nSiO2 was 0.18~0.22, amount of seeds added was 5%(w/w) and reaction time was 70 h. The ZSM-5 zeolite was characterized by X-ray diffraction, N2 adsorption-desorption, scanning electron microscope, transmission electron microscope and NH3 programmed temperature desorption. Compared with ZSM-5 zeolite synthesized by hydrothermal method of in-situ crystallization, ZSM-5 zeolite by in-situ solvent free method obtained higher crystallinity, smaller crystal size, slightly higher acid strength and little difference in pore structure. In addition, the in-situ solvent-free method not only solved the problems of large pressure of the synthesis system and waste liquid discharge, but also improved the utilization rate of the reactor volume.
By effectively combining in-situ crystallization and solvent-free method, the ZSM-5 zeolite was synthesized by seed induction and optimal synthesis conditions in a green and efficient manner on the basis of kaolin as raw material without adding organic template agent and solvent. The optimal synthesis conditions for the synthesis of ZSM-5 was:nNa2O/nSiO2 was 0.18~0.22, amount of seeds added was 5%(w/w) and reaction time was 70 h. The ZSM-5 zeolite was characterized by X-ray diffraction, N2 adsorption-desorption, scanning electron microscope, transmission electron microscope and NH3 programmed temperature desorption. Compared with ZSM-5 zeolite synthesized by hydrothermal method of in-situ crystallization, ZSM-5 zeolite by in-situ solvent free method obtained higher crystallinity, smaller crystal size, slightly higher acid strength and little difference in pore structure. In addition, the in-situ solvent-free method not only solved the problems of large pressure of the synthesis system and waste liquid discharge, but also improved the utilization rate of the reactor volume.
2020, 36(2): 295-301
doi: 10.11862/CJIC.2020.050
Abstract:
A plug-and-play Al/Ag nano surface enhanced Raman spectrum (SERS) active substrate was rapidly prepared on the aluminum plate by displacement reaction. The results showed that, with the SERS substrate, the adsorption of silver nanoparticles on the supporting can be improved, and the detection for melamine can quickly achieved. This method was with the advantages of simple operation, low cost, and no damage detection, etc. The minimum detection limit can reach 10-7 mol·L-1, and it was satisfied with the minimum standards for national food safety. In addition, the Al/Ag active substrate has an excellent reproducibility for melamine detection, continuously measured for 150 h, the Raman intensity changed little. Moreover, the Al/Ag active substrate can selectively detect melamine in amines such as triethanolamine, N, N-dimethylformamide and 1, 2-propanediamine.
A plug-and-play Al/Ag nano surface enhanced Raman spectrum (SERS) active substrate was rapidly prepared on the aluminum plate by displacement reaction. The results showed that, with the SERS substrate, the adsorption of silver nanoparticles on the supporting can be improved, and the detection for melamine can quickly achieved. This method was with the advantages of simple operation, low cost, and no damage detection, etc. The minimum detection limit can reach 10-7 mol·L-1, and it was satisfied with the minimum standards for national food safety. In addition, the Al/Ag active substrate has an excellent reproducibility for melamine detection, continuously measured for 150 h, the Raman intensity changed little. Moreover, the Al/Ag active substrate can selectively detect melamine in amines such as triethanolamine, N, N-dimethylformamide and 1, 2-propanediamine.
2020, 36(2): 302-308
doi: 10.11862/CJIC.2020.027
Abstract:
Monodispersed Cu2O micro cubes were prepared via a simple methanol-thermal reduction method by controlling the reaction temperature. The samples were characterized by using several techaniques, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectroscopy (XPS). The photocatalytic activities of the samples were tested by the photodegradation of rhodamine B (RhB) under visible light irradiation with λ>400 nm. The correlation between the physical-chemical properties and the photocatalytic acitivities of the materials were also investigated. The results indicate that monodispersed Cu2O micro cubes can be prepared at 140℃ and show the best photocatalytic activity. When the preparation temperature was increased, ultrafine copper powder was obtained, and the photocatalytic performance of the sample was reduced rapidly.
Monodispersed Cu2O micro cubes were prepared via a simple methanol-thermal reduction method by controlling the reaction temperature. The samples were characterized by using several techaniques, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectroscopy (XPS). The photocatalytic activities of the samples were tested by the photodegradation of rhodamine B (RhB) under visible light irradiation with λ>400 nm. The correlation between the physical-chemical properties and the photocatalytic acitivities of the materials were also investigated. The results indicate that monodispersed Cu2O micro cubes can be prepared at 140℃ and show the best photocatalytic activity. When the preparation temperature was increased, ultrafine copper powder was obtained, and the photocatalytic performance of the sample was reduced rapidly.
2020, 36(2): 309-316
doi: 10.11862/CJIC.2020.021
Abstract:
Ga2O3/SnO2 one-dimensional nanofibers were prepared by electrospinning method. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Visible diffuse reflection spectrum (UV-Vis DRS), etc. Gas-sensing properties of Ga2O3/SnO2 (650℃, 5 h) nanofibers with different Ga2O3 mass fractions (0, 40%, 50%, 60%, 70wt%, 100%) were prepared. The responses of gas sensors made from Ga2O3/SnO2 (650℃, 5 h) nanofibers to seven kinds of gases including trimethylamine, acetone, acetaldehyde, acetic acid, ammonia, ethanol and formaldehyde were investigated. The results showed that the 60%(w/w) Ga2O3-40%(w/w) SnO2 nanofibers had a higher response to trimethylamine, shorter response/recovery time; at room temperature (25℃), the response of this composite material to 1 000 μL·L-1 trimethylamine reached 51, the minimum detection limit for trimethylamine could reach 0.8 μL·L-1 and the response was 1.3.
Ga2O3/SnO2 one-dimensional nanofibers were prepared by electrospinning method. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Visible diffuse reflection spectrum (UV-Vis DRS), etc. Gas-sensing properties of Ga2O3/SnO2 (650℃, 5 h) nanofibers with different Ga2O3 mass fractions (0, 40%, 50%, 60%, 70wt%, 100%) were prepared. The responses of gas sensors made from Ga2O3/SnO2 (650℃, 5 h) nanofibers to seven kinds of gases including trimethylamine, acetone, acetaldehyde, acetic acid, ammonia, ethanol and formaldehyde were investigated. The results showed that the 60%(w/w) Ga2O3-40%(w/w) SnO2 nanofibers had a higher response to trimethylamine, shorter response/recovery time; at room temperature (25℃), the response of this composite material to 1 000 μL·L-1 trimethylamine reached 51, the minimum detection limit for trimethylamine could reach 0.8 μL·L-1 and the response was 1.3.
2020, 36(2): 317-323
doi: 10.11862/CJIC.2020.037
Abstract:
Hierarchical urchin-like TiO2 hollow spheres comprising rutile phase of thorn and anatase phase of hollow shell was synthesized via a simple H2O2 assisted hydrothermal method. The effects of the pH value of preparation medium and the hydrothermal treatment time on the resulting TiO2 morphology and structure were systematically investigated. The density of the thorns on the surface of hollow spheres can be effectively modified by tuning the pH value of preparation medium. A possible growth mechanism of the hierarchical structure was proposed. Photocatalytic degradation of methylene blue over the obtained TiO2 hollow spheres with different density of rutile thorn was explored. It was revealed that the TiO2 hollow spheres with less thorns outperformed the well-known photocatalyst P25-TiO2, and were much better than the TiO2 hollow spheres with more thorns and the smooth TiO2 hollow spheres.
Hierarchical urchin-like TiO2 hollow spheres comprising rutile phase of thorn and anatase phase of hollow shell was synthesized via a simple H2O2 assisted hydrothermal method. The effects of the pH value of preparation medium and the hydrothermal treatment time on the resulting TiO2 morphology and structure were systematically investigated. The density of the thorns on the surface of hollow spheres can be effectively modified by tuning the pH value of preparation medium. A possible growth mechanism of the hierarchical structure was proposed. Photocatalytic degradation of methylene blue over the obtained TiO2 hollow spheres with different density of rutile thorn was explored. It was revealed that the TiO2 hollow spheres with less thorns outperformed the well-known photocatalyst P25-TiO2, and were much better than the TiO2 hollow spheres with more thorns and the smooth TiO2 hollow spheres.
2020, 36(2): 324-332
doi: 10.11862/CJIC.2020.034
Abstract:
Carbon dots (CDs) were prepared by pyrolysis of citric acid and composited with uncapped CdS nanocrystals (NCs) via ultrasonication to obtain CdS NCs@CDs composite. The cathodic electrochemiluminescence (ECL) from CdS NCs@CDs composite film was studied, and the mechanism underlying the ECL enhancement of CdS NCs film by CDs as well. The results showed that CDs were well dispersive and of 1.5~4 nm in diameter. When the volume ratio of CDs to CdS NCs with averagely size of 4 nm was 2:3, the CdS NCs@CDs composite showed the strongest photoluminescence (PL) which originated from CDs under excitation of 360 nm. Simultaneously, the composite film generated the strongest ECL emission ascribed to excited CdS NCs. The composite film had a more positive set on potential (-1.05 V) for ECL generation. ECL emission of the composite film was pH dependent with the maximum ECL emission occurring at pH=6, meanwhile ECL was 19 times larger than that of CdS NCs film. This ECL enhancement was possibly because a large number of electrons can be trapped in CDs to generate localized electric field that facilitates formation and relaxation of excited states of neighboring CdS NCs.
Carbon dots (CDs) were prepared by pyrolysis of citric acid and composited with uncapped CdS nanocrystals (NCs) via ultrasonication to obtain CdS NCs@CDs composite. The cathodic electrochemiluminescence (ECL) from CdS NCs@CDs composite film was studied, and the mechanism underlying the ECL enhancement of CdS NCs film by CDs as well. The results showed that CDs were well dispersive and of 1.5~4 nm in diameter. When the volume ratio of CDs to CdS NCs with averagely size of 4 nm was 2:3, the CdS NCs@CDs composite showed the strongest photoluminescence (PL) which originated from CDs under excitation of 360 nm. Simultaneously, the composite film generated the strongest ECL emission ascribed to excited CdS NCs. The composite film had a more positive set on potential (-1.05 V) for ECL generation. ECL emission of the composite film was pH dependent with the maximum ECL emission occurring at pH=6, meanwhile ECL was 19 times larger than that of CdS NCs film. This ECL enhancement was possibly because a large number of electrons can be trapped in CDs to generate localized electric field that facilitates formation and relaxation of excited states of neighboring CdS NCs.
2020, 36(2): 333-344
doi: 10.11862/CJIC.2020.007
Abstract:
Porous nanosheet-aggregated persimmon-like bismuth oxybromide (BiOBr) were successfully prepared for the first time using polyvinyl pyrrolidone (PVP)-assisted solvothermal strategy with bismuth nitrate and cetyltrimethyl ammonium bromide (CTAB) as Bi and Br sources. Physicochemical properties of the hierarchical microstructure BiOBr materials were characterized by means of numerous analytical techniques, and their photocatalytic activities were evaluated for the removal of methylene blue (MB) under visible-light illumination. It is found that the solvothermal time and PVP addition had a significant influence on the particle morphology and crystallinity of the product. The porous sheet-aggregated persimmon-like BiOBr sample could be obtained after solvothermal treatment at 120℃ for 12 h in the presence of 0.7 g PVP. The porous persimmon-like BiOBr sample with a surface area of 4 m2·g-1 and a bandgap energy of 2.64 eV possessed good optical absorption property in visible-light regions and showed excellent visible-light-driven photocatalytic activity and stability for MB degradation. It is concluded that the high visible-light-driven catalytic performance of the porous sheet-aggregated persimmon-like BiOBr sample is associated with its high surface area, porous structure, and low bandgap energy as well as the unique particle morphology.
Porous nanosheet-aggregated persimmon-like bismuth oxybromide (BiOBr) were successfully prepared for the first time using polyvinyl pyrrolidone (PVP)-assisted solvothermal strategy with bismuth nitrate and cetyltrimethyl ammonium bromide (CTAB) as Bi and Br sources. Physicochemical properties of the hierarchical microstructure BiOBr materials were characterized by means of numerous analytical techniques, and their photocatalytic activities were evaluated for the removal of methylene blue (MB) under visible-light illumination. It is found that the solvothermal time and PVP addition had a significant influence on the particle morphology and crystallinity of the product. The porous sheet-aggregated persimmon-like BiOBr sample could be obtained after solvothermal treatment at 120℃ for 12 h in the presence of 0.7 g PVP. The porous persimmon-like BiOBr sample with a surface area of 4 m2·g-1 and a bandgap energy of 2.64 eV possessed good optical absorption property in visible-light regions and showed excellent visible-light-driven photocatalytic activity and stability for MB degradation. It is concluded that the high visible-light-driven catalytic performance of the porous sheet-aggregated persimmon-like BiOBr sample is associated with its high surface area, porous structure, and low bandgap energy as well as the unique particle morphology.
2020, 36(2): 345-351
doi: 10.11862/CJIC.2020.002
Abstract:
Zero-dimensional mononuclear copper(Ⅱ) coordination compound and 1D chain copper(Ⅱ) coordination polymer, namely [Cu(BIPA)(2, 2'-bipy)(H2O)2]·H2O (1) and[Cu3(μ3-BIPA)2(μ-OH)2(2, 2'-bipy)2]n (2), were constructed hydrothermally using H2BIPA (H2BIPA=5-bromoisophthalic acid), 2, 2'-bipy (2, 2'-bipy=2, 2'-bipyridine), and copper chloride at the nNaOH:nH2 BIPA (molar ratio) of 2:1 or 3:1, respectively. Single-crystal X-ray diffraction analyses reveal that both compounds crystallize in the monoclinic system, space groups P21/c or P21/n, respectively. Compound 1 discloses a discrete monomer structure, which is assembled to a 2D sheet through O-H…O hydrogen bonds. Compound 2 has a chain structure based on Cu3 unit. The chains are further extended into a 2D sheet by π-π stacking interactions. Structural differences between compounds 1 and 2 are attributed to the different molar ratio between NaOH and H2BIPA. Magnetic studies for compound 2 demonstrate an antiferromagnetic coupling between the adjacent Cu(Ⅱ) centers within Cu3 unit.
Zero-dimensional mononuclear copper(Ⅱ) coordination compound and 1D chain copper(Ⅱ) coordination polymer, namely [Cu(BIPA)(2, 2'-bipy)(H2O)2]·H2O (1) and[Cu3(μ3-BIPA)2(μ-OH)2(2, 2'-bipy)2]n (2), were constructed hydrothermally using H2BIPA (H2BIPA=5-bromoisophthalic acid), 2, 2'-bipy (2, 2'-bipy=2, 2'-bipyridine), and copper chloride at the nNaOH:nH2 BIPA (molar ratio) of 2:1 or 3:1, respectively. Single-crystal X-ray diffraction analyses reveal that both compounds crystallize in the monoclinic system, space groups P21/c or P21/n, respectively. Compound 1 discloses a discrete monomer structure, which is assembled to a 2D sheet through O-H…O hydrogen bonds. Compound 2 has a chain structure based on Cu3 unit. The chains are further extended into a 2D sheet by π-π stacking interactions. Structural differences between compounds 1 and 2 are attributed to the different molar ratio between NaOH and H2BIPA. Magnetic studies for compound 2 demonstrate an antiferromagnetic coupling between the adjacent Cu(Ⅱ) centers within Cu3 unit.
2020, 36(2): 352-360
doi: 10.11862/CJIC.2020.020
Abstract:
Circularly polarized luminescence materials based on emissive Eu(Ⅲ) complexes have attracted considerable attention in 3D-displays and bioresponsive imaging. In this work, we design and report the syntheses of a pair of chiral carboxylic-containing 2, 2'-bipyridine ligands ((+)-L and (-)-L). Through reaction with highly emissive β-diketone Eu(Ⅲ) complexes[Eu(TTA)3]·2H2O (TTA=2-thenoyltrifluoroacetone), a couple of chiral dinuclear Eu(Ⅲ) enantiomers, [Eu2((+)-L)2(TTA)2(C2H5OH)2] ((+)-1) and[Eu2((-)-L)2(TTA)2(C2H5OH)2] ((-)-1), were prepared, and the structure of (+)-1 was confirmed by single-crystal X-ray diffraction. The absorption, emission and chiroptical properties of (+)-1 and (-)-1 were investigated, and distinct CPL activities were clearly detected.
Circularly polarized luminescence materials based on emissive Eu(Ⅲ) complexes have attracted considerable attention in 3D-displays and bioresponsive imaging. In this work, we design and report the syntheses of a pair of chiral carboxylic-containing 2, 2'-bipyridine ligands ((+)-L and (-)-L). Through reaction with highly emissive β-diketone Eu(Ⅲ) complexes[Eu(TTA)3]·2H2O (TTA=2-thenoyltrifluoroacetone), a couple of chiral dinuclear Eu(Ⅲ) enantiomers, [Eu2((+)-L)2(TTA)2(C2H5OH)2] ((+)-1) and[Eu2((-)-L)2(TTA)2(C2H5OH)2] ((-)-1), were prepared, and the structure of (+)-1 was confirmed by single-crystal X-ray diffraction. The absorption, emission and chiroptical properties of (+)-1 and (-)-1 were investigated, and distinct CPL activities were clearly detected.
2020, 36(2): 361-367
doi: 10.11862/CJIC.2020.013
Abstract:
A chiral α, α-L-diaryl prolinol-pyridine derivative, (S)-bis(4-(pyridin-4-yl)phenyl)(pyrrolidin-2-yl)methanol (L), was synthesized and used to construct a chiral coordination polymer, {[Ag4(L)4](NO3)4·1.5CH3OH·1.25H2O}n (1), with Ag(Ⅰ). The polymer displayed a one-dimensional ladder-like chain structure, which was characterized by single crystal XRD, PXRD, IR spectra, TGA and luminescent spectra. CD spectra and SHG response of the compounds confirmed that the bulk sample was of structural chirality.
A chiral α, α-L-diaryl prolinol-pyridine derivative, (S)-bis(4-(pyridin-4-yl)phenyl)(pyrrolidin-2-yl)methanol (L), was synthesized and used to construct a chiral coordination polymer, {[Ag4(L)4](NO3)4·1.5CH3OH·1.25H2O}n (1), with Ag(Ⅰ). The polymer displayed a one-dimensional ladder-like chain structure, which was characterized by single crystal XRD, PXRD, IR spectra, TGA and luminescent spectra. CD spectra and SHG response of the compounds confirmed that the bulk sample was of structural chirality.
2020, 36(2): 368-376
doi: 10.11862/CJIC.2020.044
Abstract:
Based on flexible homophthalic acid (H2hmph) and diimidazolyl-type ligands, three novel coordination polymers with the formulas determined as {[Ni2(hmph)2(bib)2(H2O)2]·3H2O}n (1), [Cd(hmph)(bib)]n (2) and {[Zn(hmph)(bip)]·H2O}n (3) (bib=1, 4-bis(1-imidazolyl)benzene; bip=3, 5-bis(1-imidazolyl)pyridine) have been solvothermally synthesized. Complex 1 displays a 2D mono-layer structure featuring Ni-carboxylate chains cross-linked further by bib co-ligands. Complex 2 exhibits a 2D bilayer structure containing double-stranded Cd-carboxylate chains bridged by bib co-ligands, wherein there are carboxyl-bridged dinuclear kernels. Complex 3 is double-stranded chain featuring Zn-carboxylate binuclear units extended further by bip co-ligands. TGA experiments show that all three complexes have high thermal stabilities. And the magetic data indicate there is typical ferromagnetic exchange coupling in complex 1. Furthermore, the fluorescent properties of both complexes 2 and 3 show significant blue-shift compared with the free ligands.
Based on flexible homophthalic acid (H2hmph) and diimidazolyl-type ligands, three novel coordination polymers with the formulas determined as {[Ni2(hmph)2(bib)2(H2O)2]·3H2O}n (1), [Cd(hmph)(bib)]n (2) and {[Zn(hmph)(bip)]·H2O}n (3) (bib=1, 4-bis(1-imidazolyl)benzene; bip=3, 5-bis(1-imidazolyl)pyridine) have been solvothermally synthesized. Complex 1 displays a 2D mono-layer structure featuring Ni-carboxylate chains cross-linked further by bib co-ligands. Complex 2 exhibits a 2D bilayer structure containing double-stranded Cd-carboxylate chains bridged by bib co-ligands, wherein there are carboxyl-bridged dinuclear kernels. Complex 3 is double-stranded chain featuring Zn-carboxylate binuclear units extended further by bip co-ligands. TGA experiments show that all three complexes have high thermal stabilities. And the magetic data indicate there is typical ferromagnetic exchange coupling in complex 1. Furthermore, the fluorescent properties of both complexes 2 and 3 show significant blue-shift compared with the free ligands.
2020, 36(2): 377-384
doi: 10.11862/CJIC.2020.042
Abstract:
Two 2D manganese(Ⅱ) and zinic(Ⅱ) coordination polymers, namely {[Mn2(μ6-L)(phen)2]·5H2O}n (1) and {[Zn2(μ7-L)(py)]·H2O}n (2), have been constructed hydrothermally using H4L (H4L=3, 3', 4, 5'-diphenyl ether tetra-carboxylic acid), phen (phen=1, 10-phenanthroline), py (py=pyridine), and manganese or zinc chlorides. Single-crystal X-ray diffraction analyses revealed that two complexes crystallize in the triclinic or monoclinic systems, space groups P1 or I2/a. Both complexes feature a 2D sheet structure based on Mn4 or Zn2 subunits. The luminescent and magnetic properties for two complexes were also investigated. The results of fluorescence and magnetic studies show that complex 2 can emit blue fluorescence at room temperature, and antiferromagnetic interactions exist between adjacent Mn(Ⅱ) ions in polymer 1.
Two 2D manganese(Ⅱ) and zinic(Ⅱ) coordination polymers, namely {[Mn2(μ6-L)(phen)2]·5H2O}n (1) and {[Zn2(μ7-L)(py)]·H2O}n (2), have been constructed hydrothermally using H4L (H4L=3, 3', 4, 5'-diphenyl ether tetra-carboxylic acid), phen (phen=1, 10-phenanthroline), py (py=pyridine), and manganese or zinc chlorides. Single-crystal X-ray diffraction analyses revealed that two complexes crystallize in the triclinic or monoclinic systems, space groups P1 or I2/a. Both complexes feature a 2D sheet structure based on Mn4 or Zn2 subunits. The luminescent and magnetic properties for two complexes were also investigated. The results of fluorescence and magnetic studies show that complex 2 can emit blue fluorescence at room temperature, and antiferromagnetic interactions exist between adjacent Mn(Ⅱ) ions in polymer 1.
2020, 36(2): 385-391
doi: 10.11862/CJIC.2020.032
Abstract:
A new type oil-soluble core-shell structure Fe3O4@MnO nanocomposites with diameter about 15 nm was prepared through two-phase seed mediate method with Mn-oleate precursors. The as-prepared nanocomposites with core-shell structure were monodispersed and uniform. The products exhibited high and recyclable catalytic activity for the oxidative cyclization reaction of 2-hydroxyacetophenone and 1, 2-diaminobenzene. Compared with other reported catalysts used in this kind of cyclization reaction, the as-prepared Fe3O4@MnO nanocomposites are green, cheap and more suitable for large scale industrial applications.
A new type oil-soluble core-shell structure Fe3O4@MnO nanocomposites with diameter about 15 nm was prepared through two-phase seed mediate method with Mn-oleate precursors. The as-prepared nanocomposites with core-shell structure were monodispersed and uniform. The products exhibited high and recyclable catalytic activity for the oxidative cyclization reaction of 2-hydroxyacetophenone and 1, 2-diaminobenzene. Compared with other reported catalysts used in this kind of cyclization reaction, the as-prepared Fe3O4@MnO nanocomposites are green, cheap and more suitable for large scale industrial applications.
