Login In
2022 Volume 38 Issue 5
2022, 38(5): 777-786
doi: 10.11862/CJIC.2022.095
Abstract:
Traditionally, synthetic polymers are widely adopted in the consolidation of bone relics. However, organic materials are insufficient in weather resistance and compatibility with bone relics. For the past few years, more and more attention has been paid to inorganic protective materials because of their good weatherability and compatibility. In this paper, the characteristics, the consolidating mechanism, and the research actuality of inorganic protective materials are reviewed.
Traditionally, synthetic polymers are widely adopted in the consolidation of bone relics. However, organic materials are insufficient in weather resistance and compatibility with bone relics. For the past few years, more and more attention has been paid to inorganic protective materials because of their good weatherability and compatibility. In this paper, the characteristics, the consolidating mechanism, and the research actuality of inorganic protective materials are reviewed.
2022, 38(5): 787-799
doi: 10.11862/CJIC.2022.103
Abstract:
Pt nanowires (Pt NWs) have been demonstrated to have a higher specific activity of oxygen reduction reaction (ORR) than that of commercial Pt/C due to their unique structural characteristics. In this work, a cathode with a uniform distribution of Pt NWs was obtained by introducing preformed Pt nanoparticles (NPs) into the carbon matrix to induce Pt NW growth. The structure and performance of the as-prepared cathode were investigated by altering Pt NP loadings (0-0.015 mg·cm-2) and Pt NP sources (Pt/C with different Pt contents). The cathode surface was characterized by scanning electron microscopy (SEM), and the morphology and crystal structure of Pt NW were analyzed by transmission electron microscopy (TEM) and X -ray diffraction (XRD). Polarization and cyclic voltamme-try curves were obtained in single cells. The best single-cell performance, as well as the largest electrochemical surface area (ECSA) value was achieved by the cathode with preformed Pt NP loading of 0.005 mg·cm-2 originating from 40% Pt/C. Finally, a possible mechanism for the influence of preformed Pt NPs in the Pt NW distribution was proposed.
Pt nanowires (Pt NWs) have been demonstrated to have a higher specific activity of oxygen reduction reaction (ORR) than that of commercial Pt/C due to their unique structural characteristics. In this work, a cathode with a uniform distribution of Pt NWs was obtained by introducing preformed Pt nanoparticles (NPs) into the carbon matrix to induce Pt NW growth. The structure and performance of the as-prepared cathode were investigated by altering Pt NP loadings (0-0.015 mg·cm-2) and Pt NP sources (Pt/C with different Pt contents). The cathode surface was characterized by scanning electron microscopy (SEM), and the morphology and crystal structure of Pt NW were analyzed by transmission electron microscopy (TEM) and X -ray diffraction (XRD). Polarization and cyclic voltamme-try curves were obtained in single cells. The best single-cell performance, as well as the largest electrochemical surface area (ECSA) value was achieved by the cathode with preformed Pt NP loading of 0.005 mg·cm-2 originating from 40% Pt/C. Finally, a possible mechanism for the influence of preformed Pt NPs in the Pt NW distribution was proposed.
2022, 38(5): 800-804
doi: 10.11862/CJIC.2022.100
Abstract:
γ-CD-MOFs were synthesized with γ-cyclodextrin (γ-CD), potassium hydroxide, methanol, and water, whose structure, stability, and morphology were characterized by X-ray diffraction, thermogravimetric analysis, and scanning electron microscope. Due to γ- CD- MOFs having a 1D channel, rhodamine 6G (R6G) with yellow light emission was introduced into the channel, to obtain a fluorescent composite R6G@γ-CD-MOFs and its fluorescence response to different metal ions was explored. The experimental results show that R6G@γ-CD-MOFs can selectively sense Fe3+ ions from 12 kinds of metal ions, and its fluorescence quenching constant (Ksv) was 1.03×104 L·mol-1 in a range of 2×10-4-2.0×10-2 mol·L-1.
γ-CD-MOFs were synthesized with γ-cyclodextrin (γ-CD), potassium hydroxide, methanol, and water, whose structure, stability, and morphology were characterized by X-ray diffraction, thermogravimetric analysis, and scanning electron microscope. Due to γ- CD- MOFs having a 1D channel, rhodamine 6G (R6G) with yellow light emission was introduced into the channel, to obtain a fluorescent composite R6G@γ-CD-MOFs and its fluorescence response to different metal ions was explored. The experimental results show that R6G@γ-CD-MOFs can selectively sense Fe3+ ions from 12 kinds of metal ions, and its fluorescence quenching constant (Ksv) was 1.03×104 L·mol-1 in a range of 2×10-4-2.0×10-2 mol·L-1.
2022, 38(5): 805-811
doi: 10.11862/CJIC.2022.088
Abstract:
In order to solve the problems such as poor electrical conductivity of sulfur, the large volume expansion and the shuttle effect of intermediate polysulfides during the cycling process, the S/PCNT composites were prepared by introducing sulfur into porous carbon nanotubes (PCNTs), the electrochemical performance of S/PCNT was investigat-ed. Compared with S/CNT, the electrochemical performance of S/PCNT has been significantly improved. This can be attributed to the embedded structure of S/PCNT, which has provided buffer space for the volume expansion during the charge and discharge process, avoided the direct contact between sulfur and electrolytes, restricted the dissolution of polysulfides, and alleviated the shuttle effect of polysulfides. Therefore, S/PCNT has better cycling stability.
In order to solve the problems such as poor electrical conductivity of sulfur, the large volume expansion and the shuttle effect of intermediate polysulfides during the cycling process, the S/PCNT composites were prepared by introducing sulfur into porous carbon nanotubes (PCNTs), the electrochemical performance of S/PCNT was investigat-ed. Compared with S/CNT, the electrochemical performance of S/PCNT has been significantly improved. This can be attributed to the embedded structure of S/PCNT, which has provided buffer space for the volume expansion during the charge and discharge process, avoided the direct contact between sulfur and electrolytes, restricted the dissolution of polysulfides, and alleviated the shuttle effect of polysulfides. Therefore, S/PCNT has better cycling stability.
2022, 38(5): 812-820
doi: 10.11862/CJIC.2022.087
Abstract:
Hydrogenation of phenol to cyclohexanone is a vital step in the production of synthetic fiber (nylon). In this work, a layered-structured solid acid (zirconium hydrogen phosphate, ZrHP) supported Pd catalyst was synthe- sized in a microwave method. The structure and property of Pd/ZrHP catalyst were characterized via X-ray diffrac- tion (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), nitro- gen adsorption- desorption, X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption (TPD) technologies. It was found that Pd/ZrHP catalyst exhibited better performance than the Pd-based catalysts supported by traditional oxide (Al2O3, SiO2, MgO), molecular sieve (H-Beta), and active carbon (XC-72) under the mild condi- tion (100 ℃, 1.0 MPa H2). The specific activity of the surface Pd atom in Pd/ZrHP reached 612.2 h-1, and it could be recycled five times without obvious deactivation. The synergistic effect between Pd metal and the acidic sites on ZrHP surface might be the main reason for the selective formation of cyclohexanone.
Hydrogenation of phenol to cyclohexanone is a vital step in the production of synthetic fiber (nylon). In this work, a layered-structured solid acid (zirconium hydrogen phosphate, ZrHP) supported Pd catalyst was synthe- sized in a microwave method. The structure and property of Pd/ZrHP catalyst were characterized via X-ray diffrac- tion (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), nitro- gen adsorption- desorption, X-ray photoelectron spectroscopy (XPS), and temperature-programmed desorption (TPD) technologies. It was found that Pd/ZrHP catalyst exhibited better performance than the Pd-based catalysts supported by traditional oxide (Al2O3, SiO2, MgO), molecular sieve (H-Beta), and active carbon (XC-72) under the mild condi- tion (100 ℃, 1.0 MPa H2). The specific activity of the surface Pd atom in Pd/ZrHP reached 612.2 h-1, and it could be recycled five times without obvious deactivation. The synergistic effect between Pd metal and the acidic sites on ZrHP surface might be the main reason for the selective formation of cyclohexanone.
2022, 38(5): 821-828
doi: 10.11862/CJIC.2022.086
Abstract:
Four charge-transfer complexes, (1+·)(Cu2Br6)0.5, (2+·)(Cu2Br6)0.5, (3+·)(Cu2Br6)0.5 and (4+·)(CuBr2), have been prepared via diffusion methods comprising arylthio-substituted tetrathiafulvalene derivatives 1-4 and CuBr2. Crystal-lographic studies indicate that the anions in the complexes, which are derived from CuBr2, show diverse configura-tions including octahedral (CuⅡ2Br 6)2-and linear (CuⅠBr2)-. The plane of the outer four Br atoms and the plane of the central quadrilateral on(CuⅡ2Br6)2-have a different dihedral angle. Compounds 1-4 show radical cation and the cen-tral framework of compounds 1-4 are nearly planar in the complexes. The stacking structure and anionic configura-tion of the charge transfer complexes can be effectively regulated by regulating the substitution positions and sizes of halogen atoms on the aryl groups. CCDC: 2119456, (1+·)(Cu2Br6)0.5;2119457, (2+·)(Cu2Br6)0.5;2119458, (3+·)(Cu2Br6)0.5;2119459, (4+·)(CuBr2).
Four charge-transfer complexes, (1+·)(Cu2Br6)0.5, (2+·)(Cu2Br6)0.5, (3+·)(Cu2Br6)0.5 and (4+·)(CuBr2), have been prepared via diffusion methods comprising arylthio-substituted tetrathiafulvalene derivatives 1-4 and CuBr2. Crystal-lographic studies indicate that the anions in the complexes, which are derived from CuBr2, show diverse configura-tions including octahedral (CuⅡ2Br 6)2-and linear (CuⅠBr2)-. The plane of the outer four Br atoms and the plane of the central quadrilateral on(CuⅡ2Br6)2-have a different dihedral angle. Compounds 1-4 show radical cation and the cen-tral framework of compounds 1-4 are nearly planar in the complexes. The stacking structure and anionic configura-tion of the charge transfer complexes can be effectively regulated by regulating the substitution positions and sizes of halogen atoms on the aryl groups. CCDC: 2119456, (1+·)(Cu2Br6)0.5;2119457, (2+·)(Cu2Br6)0.5;2119458, (3+·)(Cu2Br6)0.5;2119459, (4+·)(CuBr2).
2022, 38(5): 829-835
doi: 10.11862/CJIC.2022.084
Abstract:
Upconversion nanoparticles have been limited to further development in the field of application due to their low luminescence efficiency. Surface plasmon modulation using noble metal has been developed as an effective way to enhance upconversion luminescence. In this work, the noble metal ricelike structure with a simple synthetic procedure was obtained through regulating the localized electric field around upconversion nanoparticles for improving upconversion luminescence intensity. The 3D finite element method was employed to investigate the effect of the different contact modes between Ag rices in the actual films on induced localized electric field enhancement. Further, this enhancement effect caused by plasmon-coupling is a crucial contribution in this upconversionmodulated system. And the upconversion intensity improvement of nearly 100 times was acquired. Finally, the upconversion luminescence performance can be further optimized by adjusting the thickness of the plasmonic layer and luminescence layer.
Upconversion nanoparticles have been limited to further development in the field of application due to their low luminescence efficiency. Surface plasmon modulation using noble metal has been developed as an effective way to enhance upconversion luminescence. In this work, the noble metal ricelike structure with a simple synthetic procedure was obtained through regulating the localized electric field around upconversion nanoparticles for improving upconversion luminescence intensity. The 3D finite element method was employed to investigate the effect of the different contact modes between Ag rices in the actual films on induced localized electric field enhancement. Further, this enhancement effect caused by plasmon-coupling is a crucial contribution in this upconversionmodulated system. And the upconversion intensity improvement of nearly 100 times was acquired. Finally, the upconversion luminescence performance can be further optimized by adjusting the thickness of the plasmonic layer and luminescence layer.
2022, 38(5): 836-842
doi: 10.11862/CJIC.2022.089
Abstract:
Using trimellitic acid and cobalt nitrate hexahydrate as raw materials, two cobalt-based metal-organic polymers (Co-MOP) with different reaction times were synthesized by the hydrothermal method. The structure and morphology of Co-MOP were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and N2 adsorption-desorption test. Two cobalt-based metal-organic polymer materials were used as anode materials for lithium-ion batteries, and the electrochemical performance tests were carried out. The results showed that Co-MOP-12 (hydrothermal reaction for 12 h) exhibited excellent electrochemical performance. The first-cycle reversible specific capacity the of Co-MOP-12 electrode reached 979 mAh·g-1 at a current density of 100 mA·g-1. The specific capacity was as high as 1 345 mAh·g-1 after 100 cycles.
Using trimellitic acid and cobalt nitrate hexahydrate as raw materials, two cobalt-based metal-organic polymers (Co-MOP) with different reaction times were synthesized by the hydrothermal method. The structure and morphology of Co-MOP were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and N2 adsorption-desorption test. Two cobalt-based metal-organic polymer materials were used as anode materials for lithium-ion batteries, and the electrochemical performance tests were carried out. The results showed that Co-MOP-12 (hydrothermal reaction for 12 h) exhibited excellent electrochemical performance. The first-cycle reversible specific capacity the of Co-MOP-12 electrode reached 979 mAh·g-1 at a current density of 100 mA·g-1. The specific capacity was as high as 1 345 mAh·g-1 after 100 cycles.
2022, 38(5): 843-849
doi: 10.11862/CJIC.2022.101
Abstract:
The β-diketiminate ligands without substituents containing active sites exhibit good electron stabilization effect and sterically protection for the low-valent metal center. Potassium was able to reduce β-diketiminato gallium(Ⅲ) dichloride PhC(PhCN-Dip)2GaCl2 (2, Dip=2, 6-iPr2C6H3) to highly yield a new β-diketiminato gallium(Ⅰ) carbene analogue PhC(PhCN-Dip)2 Ga: (3) as a monomeric molecule. The structures and composition of compounds 2 and 3 were characterized by the X-ray single-crystal diffraction and the NMR spectroscopies. The central Ga(Ⅰ) ion of 3 occupies a point angle of the six-membered N-heterocyclic plane with a distorted two-coordinate geometry. Theoretical calculations show that the HOMO corresponded to the lone pair electrons at the Ga center, which had a low energy level of -6.352 eV, while the LUMO+1 was associated with the empty p-orbital of Ga with an energy of 601.0 kJ·mol-1 higher than the HOMO, indicating that 3 is a gallium(Ⅰ) carbene analogue and isostructural to N-heterocyclic carbene, and the lone pair of Ga(Ⅰ) ion has good thermal stability. CCDC: 2123086, 2; 2123087, 3.
The β-diketiminate ligands without substituents containing active sites exhibit good electron stabilization effect and sterically protection for the low-valent metal center. Potassium was able to reduce β-diketiminato gallium(Ⅲ) dichloride PhC(PhCN-Dip)2GaCl2 (2, Dip=2, 6-iPr2C6H3) to highly yield a new β-diketiminato gallium(Ⅰ) carbene analogue PhC(PhCN-Dip)2 Ga: (3) as a monomeric molecule. The structures and composition of compounds 2 and 3 were characterized by the X-ray single-crystal diffraction and the NMR spectroscopies. The central Ga(Ⅰ) ion of 3 occupies a point angle of the six-membered N-heterocyclic plane with a distorted two-coordinate geometry. Theoretical calculations show that the HOMO corresponded to the lone pair electrons at the Ga center, which had a low energy level of -6.352 eV, while the LUMO+1 was associated with the empty p-orbital of Ga with an energy of 601.0 kJ·mol-1 higher than the HOMO, indicating that 3 is a gallium(Ⅰ) carbene analogue and isostructural to N-heterocyclic carbene, and the lone pair of Ga(Ⅰ) ion has good thermal stability. CCDC: 2123086, 2; 2123087, 3.
2022, 38(5): 850-860
doi: 10.11862/CJIC.2022.093
Abstract:
SnO2 has the advantages of the wide bandgap, high optical transparency, high electron mobility, excellent UV stability, and lower preparation temperature. It is widely used in high-efficiency and stable perovskite solar cells (PSCs). However, the surface defects of SnO2 can cause serious hysteresis and other adverse effects. In order to improve the interfacial charge transport characteristics and hysteresis of perovskite solar cells based on the SnO2 electron transport layer. Four different types of SnO2 electron transport layers were prepared as electron transport layers (ETLs) for PSCs using low-temperature solution processing technology. SnCl4·5H2O (Cl4-SnO2), SnCl2·2H2O (Cl2-SnO2), and SnO2 nanoparticle (NP-SnO2) were used to form the bilayer ETL structure with SnO2 colloidal (Col-SnO2). The effects of different SnO2 bilayer ETLs on the photoelectric performance and hysteresis of the device were systematically studied. Through analysis of scanning electron microscopy (SEM), X-ray diffraction (XRD), steady-state photoluminescence spectrum (PL), electrochemical impedance (EIS), and stability test, it can be confirmed that the surface of Cl4-SnO2/Col-SnO2 and Cl2-SnO2/Col-SnO2 films was smooth and compact with good coverage; and inserting a Cl2-SnO2 layer under the Col-SnO2 layer can form better interface contact and fewer interfacial defects, which is beneficial to reduce the interfacial resistance and charge recombination, and exhibits more excellent electron extraction and transport characteristics. However, the nanostructure composed of the NP-SnO2 layer and the Col-SnO2 layer is not conducive to the growth of perovskite crystals, and the incompatible interface between the two causes serious charge recombination, which will affect the charge transfer. Compared with the device based on the Col-SnO2 single ETL device (14.16%), the device based on the Cl2-SnO2/Col-SnO2 bilayer structure obtained a photoelectric conversion efficiency of 15.01%, and the photoelectric conversion efficiency of the forward scan was increased by about 23.3%, short circuit current density (Jsc) and fill factor (FF) were improved, the hysteresis was obviously suppressed and showed better stability.
SnO2 has the advantages of the wide bandgap, high optical transparency, high electron mobility, excellent UV stability, and lower preparation temperature. It is widely used in high-efficiency and stable perovskite solar cells (PSCs). However, the surface defects of SnO2 can cause serious hysteresis and other adverse effects. In order to improve the interfacial charge transport characteristics and hysteresis of perovskite solar cells based on the SnO2 electron transport layer. Four different types of SnO2 electron transport layers were prepared as electron transport layers (ETLs) for PSCs using low-temperature solution processing technology. SnCl4·5H2O (Cl4-SnO2), SnCl2·2H2O (Cl2-SnO2), and SnO2 nanoparticle (NP-SnO2) were used to form the bilayer ETL structure with SnO2 colloidal (Col-SnO2). The effects of different SnO2 bilayer ETLs on the photoelectric performance and hysteresis of the device were systematically studied. Through analysis of scanning electron microscopy (SEM), X-ray diffraction (XRD), steady-state photoluminescence spectrum (PL), electrochemical impedance (EIS), and stability test, it can be confirmed that the surface of Cl4-SnO2/Col-SnO2 and Cl2-SnO2/Col-SnO2 films was smooth and compact with good coverage; and inserting a Cl2-SnO2 layer under the Col-SnO2 layer can form better interface contact and fewer interfacial defects, which is beneficial to reduce the interfacial resistance and charge recombination, and exhibits more excellent electron extraction and transport characteristics. However, the nanostructure composed of the NP-SnO2 layer and the Col-SnO2 layer is not conducive to the growth of perovskite crystals, and the incompatible interface between the two causes serious charge recombination, which will affect the charge transfer. Compared with the device based on the Col-SnO2 single ETL device (14.16%), the device based on the Cl2-SnO2/Col-SnO2 bilayer structure obtained a photoelectric conversion efficiency of 15.01%, and the photoelectric conversion efficiency of the forward scan was increased by about 23.3%, short circuit current density (Jsc) and fill factor (FF) were improved, the hysteresis was obviously suppressed and showed better stability.
2022, 38(5): 861-872
doi: 10.11862/CJIC.2022.085
Abstract:
In this work, Bi2S3 and CdSe were used to modify a TiO2 nanotube film for obtaining a Bi2S3/CdSe/TiO2 composite film with enhanced photoelectrochemical performance. The TiO2 nanotube array film was fabricated on a Ti foil by anodic oxidation. CdSe was formed on the TiO2 nanotube film by constant current electrodeposition, and then Bi2S3 was prepared on the binary CdSe/TiO2 composite film by successive ionic layer adsorption and reaction to obtain a Bi2S3/CdSe co-modified TiO2 nanotube composite film with a cascade band structure. The results showed that the Bi2S3/CdSe/TiO2 nanotube composite film showed enhanced photoabsorption in the visible light range, and its photoelectrochemical performance was greatly improved. Under white light illumination, the photocurrent density of this ternary composite film reached 670 µA·cm-2, which was about 17.6 times that of the TiO2 nanotube film. The Bi2S3/CdSe/TiO2 composite film could provide excellent photoelectrochemical cathodic protection for 403 stainless steel (403SS) in a 0.5 mol·L-1 NaCl solution, and reduced the potential of 403SS by 690 mV relative to its corrosion potential.
In this work, Bi2S3 and CdSe were used to modify a TiO2 nanotube film for obtaining a Bi2S3/CdSe/TiO2 composite film with enhanced photoelectrochemical performance. The TiO2 nanotube array film was fabricated on a Ti foil by anodic oxidation. CdSe was formed on the TiO2 nanotube film by constant current electrodeposition, and then Bi2S3 was prepared on the binary CdSe/TiO2 composite film by successive ionic layer adsorption and reaction to obtain a Bi2S3/CdSe co-modified TiO2 nanotube composite film with a cascade band structure. The results showed that the Bi2S3/CdSe/TiO2 nanotube composite film showed enhanced photoabsorption in the visible light range, and its photoelectrochemical performance was greatly improved. Under white light illumination, the photocurrent density of this ternary composite film reached 670 µA·cm-2, which was about 17.6 times that of the TiO2 nanotube film. The Bi2S3/CdSe/TiO2 composite film could provide excellent photoelectrochemical cathodic protection for 403 stainless steel (403SS) in a 0.5 mol·L-1 NaCl solution, and reduced the potential of 403SS by 690 mV relative to its corrosion potential.
2022, 38(5): 873-883
doi: 10.11862/CJIC.2022.091
Abstract:
An in-situ nitrogen-doped hierarchical porous carbon material was prepared via a simultaneous activation/carbonization process using biomass passiflora edulis peel and KHCO3 as carbon source and activator, respectively. The as-prepared porous carbon was composited with elemental sulfur to obtain the porous carbon/sulfur cathode material. The phase composition, microstructure, specific surface area, and pore structure of the as-prepared materials were investigated by these characterization techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and so on. Also, the adsorption effect of polysulfides using porous carbon as an adsorbing material was studied by UV-Vis absorption spectroscopy. The electrochemical performances of porous carbon/sulfur composite cathodes with different sulfur content from 60% to 80% were studied by galvanostatic charge/discharge test. Results showed that the asprepared material was amorphous porous carbon with a high specific surface area of 1 093 m2 ·g-1 and pore volume of 0.63 cm3·g-1. The physicochemical synergistic adsorption of polysulfides through abundant porous structure and in‑situ nitrogen doping effectively suppresses the"shuttle effect"of lithium-sulfur batteries, whilst improving the discharge capacity and cycle performance. Consequently, the porous carbon/sulfur composite cathode with a sulfur content of 60% delivered high initial discharge capacities of 1 057.7 and 763.4 mAh·g-1 at 0.05C and 0.2C, respectively. At a high current rate of 1C, a long life of 300 cycles with a capacity retention rate of 75% can be achieved.
An in-situ nitrogen-doped hierarchical porous carbon material was prepared via a simultaneous activation/carbonization process using biomass passiflora edulis peel and KHCO3 as carbon source and activator, respectively. The as-prepared porous carbon was composited with elemental sulfur to obtain the porous carbon/sulfur cathode material. The phase composition, microstructure, specific surface area, and pore structure of the as-prepared materials were investigated by these characterization techniques including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and so on. Also, the adsorption effect of polysulfides using porous carbon as an adsorbing material was studied by UV-Vis absorption spectroscopy. The electrochemical performances of porous carbon/sulfur composite cathodes with different sulfur content from 60% to 80% were studied by galvanostatic charge/discharge test. Results showed that the asprepared material was amorphous porous carbon with a high specific surface area of 1 093 m2 ·g-1 and pore volume of 0.63 cm3·g-1. The physicochemical synergistic adsorption of polysulfides through abundant porous structure and in‑situ nitrogen doping effectively suppresses the"shuttle effect"of lithium-sulfur batteries, whilst improving the discharge capacity and cycle performance. Consequently, the porous carbon/sulfur composite cathode with a sulfur content of 60% delivered high initial discharge capacities of 1 057.7 and 763.4 mAh·g-1 at 0.05C and 0.2C, respectively. At a high current rate of 1C, a long life of 300 cycles with a capacity retention rate of 75% can be achieved.
2022, 38(5): 884-890
doi: 10.11862/CJIC.2022.102
Abstract:
The all-inorganic lead-free perovskite Cs2TiBr6 has the advantages of good optoelectronic properties, adjustable bandgap, and environmental friendliness. It is a kind of light-absorbing material with great potential. To improve the related properties of Cs2TiBr6, the first-principles-based method was used to study the structure of Pd and Cl doped Cs2TiBr6 perovskite. The results show that the impurity band was generated after replacing Ti with Pd, which transforms the original indirect bandgap Cs2TiBr6 into a direct bandgap material. After doping with 25.0% Pd, the bandgap value of the crystal was reduced by 26%, and the absorption capacity of the doped crystal in the nearultraviolet region of 320-415 nm was enhanced by about 50%. In the infrared and near-infrared regions of 645-900 nm, the light absorption capacity was enhanced by about 134%. On this basis, when Cl was co-doped with 25.0% Pd, Cl doping can reduce the formation energy of Pd by about 9% based on single doping, and the position of Cl doping also affects the photoelectric properties of the material.
The all-inorganic lead-free perovskite Cs2TiBr6 has the advantages of good optoelectronic properties, adjustable bandgap, and environmental friendliness. It is a kind of light-absorbing material with great potential. To improve the related properties of Cs2TiBr6, the first-principles-based method was used to study the structure of Pd and Cl doped Cs2TiBr6 perovskite. The results show that the impurity band was generated after replacing Ti with Pd, which transforms the original indirect bandgap Cs2TiBr6 into a direct bandgap material. After doping with 25.0% Pd, the bandgap value of the crystal was reduced by 26%, and the absorption capacity of the doped crystal in the nearultraviolet region of 320-415 nm was enhanced by about 50%. In the infrared and near-infrared regions of 645-900 nm, the light absorption capacity was enhanced by about 134%. On this basis, when Cl was co-doped with 25.0% Pd, Cl doping can reduce the formation energy of Pd by about 9% based on single doping, and the position of Cl doping also affects the photoelectric properties of the material.
2022, 38(5): 891-900
doi: 10.11862/CJIC.2022.090
Abstract:
ZnS@C/reduce graphene oxide (rGO) composite was prepared by solvothermal reaction-hydrothermal treatment route. ZnS nanocrystal coated by amorphous carbon (ZnS@C) was prepared by the first-step solvothermal reaction, then ZnS@C/rGO was prepared by the second-step hydrothermal treatment. The morphology and microstructure of samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Electrochemical test results demonstrated that the as-prepared ZnS@C/rGO composite exhibited significantly enhanced electrochemical lithium storage performance in comparison to ZnS@C and ZnS/rGO. At the current density of 100 mA·g-1, ZnS@C/rGO electrode delivered the reversible specific capacity of 1 101 mAh·g-1 and 1 569 mAh·g-1, respectively, at the 1st and 100th cycle. After 1 200 cycles at the different current densities, the reversible specific capacity of 1 096 mAh·g-1 was remained at 2.0 A·g-1, indicating its stable long-cycle performance.
ZnS@C/reduce graphene oxide (rGO) composite was prepared by solvothermal reaction-hydrothermal treatment route. ZnS nanocrystal coated by amorphous carbon (ZnS@C) was prepared by the first-step solvothermal reaction, then ZnS@C/rGO was prepared by the second-step hydrothermal treatment. The morphology and microstructure of samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Electrochemical test results demonstrated that the as-prepared ZnS@C/rGO composite exhibited significantly enhanced electrochemical lithium storage performance in comparison to ZnS@C and ZnS/rGO. At the current density of 100 mA·g-1, ZnS@C/rGO electrode delivered the reversible specific capacity of 1 101 mAh·g-1 and 1 569 mAh·g-1, respectively, at the 1st and 100th cycle. After 1 200 cycles at the different current densities, the reversible specific capacity of 1 096 mAh·g-1 was remained at 2.0 A·g-1, indicating its stable long-cycle performance.
2022, 38(5): 901-912
doi: 10.11862/CJIC.2022.082
Abstract:
In this study, selective production of methanol carbonylation formed acetic acid using hydrothermal synthesis nanoporous zeolite molecular sieve as the catalyst. The incorporation of a suitable amount of metal not only facilitated the formation of acidity but also improved the efficiency of methanol carbonylation. The HZSM-5 catalyst was modified with Pt, Pd, Cu, Au, Zn by negative pressure deposition precipitation method to prepare catalysts with different acidities. Using X-ray diffraction, temperature-programmed desorption of ammonia, pyridine adsorption FTIR, N2 adsorption-desorption, and X-ray fluorescence analysis, the effect of different metals on the physico-chemical properties of the catalyst was studied, and the modification of HZSM-5 with different metals was investigated in the process of methanol carbonylation on the distribution and yield of methanol carbonyl products. The introduction of different metals had little effect on the specific surface area, pore size, and pore volume of the HZSM-5 catalyst, but significantly changed the acid strength of the catalyst surface. Pt, Au, Zn, and Cu modified HZSM-5 were favorable for the carbonylation of methanol to form methyl acetate and methyl formate. Cu-modified catalyst had a methanol conversion rate of 90.2% at 400 ℃, which was 12% higher than that of pristine HZSM-5, but the selectivity to the target product was lower than those of Pt/HZSM-5 and Au/HZSM-5. In a word, the introduction of metals changes the number of Br-nsted acid (B acid) and Lewis acid (L acid) centers on the catalyst surface. The conversion rate of methanol increased with the total acid sites. When the ratio of B acid to L acid on the catalyst surface was between 0.3 and 0.5, the catalyst showed better carbonylation activity.
In this study, selective production of methanol carbonylation formed acetic acid using hydrothermal synthesis nanoporous zeolite molecular sieve as the catalyst. The incorporation of a suitable amount of metal not only facilitated the formation of acidity but also improved the efficiency of methanol carbonylation. The HZSM-5 catalyst was modified with Pt, Pd, Cu, Au, Zn by negative pressure deposition precipitation method to prepare catalysts with different acidities. Using X-ray diffraction, temperature-programmed desorption of ammonia, pyridine adsorption FTIR, N2 adsorption-desorption, and X-ray fluorescence analysis, the effect of different metals on the physico-chemical properties of the catalyst was studied, and the modification of HZSM-5 with different metals was investigated in the process of methanol carbonylation on the distribution and yield of methanol carbonyl products. The introduction of different metals had little effect on the specific surface area, pore size, and pore volume of the HZSM-5 catalyst, but significantly changed the acid strength of the catalyst surface. Pt, Au, Zn, and Cu modified HZSM-5 were favorable for the carbonylation of methanol to form methyl acetate and methyl formate. Cu-modified catalyst had a methanol conversion rate of 90.2% at 400 ℃, which was 12% higher than that of pristine HZSM-5, but the selectivity to the target product was lower than those of Pt/HZSM-5 and Au/HZSM-5. In a word, the introduction of metals changes the number of Br-nsted acid (B acid) and Lewis acid (L acid) centers on the catalyst surface. The conversion rate of methanol increased with the total acid sites. When the ratio of B acid to L acid on the catalyst surface was between 0.3 and 0.5, the catalyst showed better carbonylation activity.
2022, 38(5): 913-920
doi: 10.11862/CJIC.2022.083
Abstract:
In this study, a water-soluble diiron carbonyl complex, [Fe2(μ-SCH2R)2(CO)6] (R=CH(OH)CH2(OH), 1), which has the potential as a CO-releasing molecule (CORM), was used to spectroscopically investigate its interaction with some biological molecules, such as hemoglobin (Hb), myoglobin (Mb), bovine serum albumin (BSA), glutathione (GSH), and DNA. The IR spectroscopic results showed that the proteins and GSH could promote the decomposition of complex 1 to release CO. All the CO-release progress followed the first-order kinetic model and GSH possessed the highest efficiency in promoting CO-release. UV absorption spectral variations and fluorescent quench effect also indicated the interactions between these biologically relevant molecules and the diiron carbonyl complex. CD spectra of the mixture of the proteins and complex 1 indicated that no conformational changes in the proteins are induced. The interactions between pUC19 plasmid DNA and complex 1 suggested that the complex could not cause DNA damage.
In this study, a water-soluble diiron carbonyl complex, [Fe2(μ-SCH2R)2(CO)6] (R=CH(OH)CH2(OH), 1), which has the potential as a CO-releasing molecule (CORM), was used to spectroscopically investigate its interaction with some biological molecules, such as hemoglobin (Hb), myoglobin (Mb), bovine serum albumin (BSA), glutathione (GSH), and DNA. The IR spectroscopic results showed that the proteins and GSH could promote the decomposition of complex 1 to release CO. All the CO-release progress followed the first-order kinetic model and GSH possessed the highest efficiency in promoting CO-release. UV absorption spectral variations and fluorescent quench effect also indicated the interactions between these biologically relevant molecules and the diiron carbonyl complex. CD spectra of the mixture of the proteins and complex 1 indicated that no conformational changes in the proteins are induced. The interactions between pUC19 plasmid DNA and complex 1 suggested that the complex could not cause DNA damage.
2022, 38(5): 921-929
doi: 10.11862/CJIC.2022.094
Abstract:
By utilizing a polydentate Schiff base ligand (H2L=pyridine-2-carboxylic acid (3, 5-di-tert-butyl-2-hydroxy-benzylidene)-hydrazide), reacting with Gd(dbm)3·2H2O (Hdbm=dibenzoylmethane) and Gd(NO)3·6H2O, respectively; two new Gd2 complexes formulated as [Gd2(L)2(dbm)2(C2H5OH)2] (1) and [Gd2(L)2(HL)2(DMF)]·2CH3CN (2) (DMF=N, N-dimethylformamide) have been obtained by using solvothermal method. The crystal structures and magnetic properties of the two Gd2 complexes have been systematically studied. The crystal structures study reveals that each eightcoordinate Gd3+ ion in 1 possesses a distorted triangular dodecahedron; the two central Gd(Ⅲ) ions are connected by two μ2-O, resulting in a rhombic-shaped Gd2O2 core. However, for 2, each central Gd(Ⅲ) ion is nine-coordinate and their coordination configurations can be described as distorted spherical capped square antiprism, and the two central Gd(Ⅲ) ions are connected by three μ2-O forming a triangular biconical-shaped Gd2O3 core. Magnetic investi-gations showed that the two Gd2 complexes displayed magnetic refrigeration properties with the magnetic entropy (-ΔSm) of 20.16 J·K-1·kg-1 for 1 and 17.14 J·K-1·kg-1 for 2 at ΔH=70 kOe and T=2.0 K. CCDC: 2111657, 1; 2111658, 2.
By utilizing a polydentate Schiff base ligand (H2L=pyridine-2-carboxylic acid (3, 5-di-tert-butyl-2-hydroxy-benzylidene)-hydrazide), reacting with Gd(dbm)3·2H2O (Hdbm=dibenzoylmethane) and Gd(NO)3·6H2O, respectively; two new Gd2 complexes formulated as [Gd2(L)2(dbm)2(C2H5OH)2] (1) and [Gd2(L)2(HL)2(DMF)]·2CH3CN (2) (DMF=N, N-dimethylformamide) have been obtained by using solvothermal method. The crystal structures and magnetic properties of the two Gd2 complexes have been systematically studied. The crystal structures study reveals that each eightcoordinate Gd3+ ion in 1 possesses a distorted triangular dodecahedron; the two central Gd(Ⅲ) ions are connected by two μ2-O, resulting in a rhombic-shaped Gd2O2 core. However, for 2, each central Gd(Ⅲ) ion is nine-coordinate and their coordination configurations can be described as distorted spherical capped square antiprism, and the two central Gd(Ⅲ) ions are connected by three μ2-O forming a triangular biconical-shaped Gd2O3 core. Magnetic investi-gations showed that the two Gd2 complexes displayed magnetic refrigeration properties with the magnetic entropy (-ΔSm) of 20.16 J·K-1·kg-1 for 1 and 17.14 J·K-1·kg-1 for 2 at ΔH=70 kOe and T=2.0 K. CCDC: 2111657, 1; 2111658, 2.
2022, 38(5): 930-940
doi: 10.11862/CJIC.2022.098
Abstract:
Using special compound {[Co(bpy)2]3[Fe(CN) 6]2}[Fe(CN)6]1/3 as a precursor, an ordered mesoporous Fe-Co- N-doped graphite - based catalyst (Fe-Co-N-GC) with the embedding Fe—N, Co— N, and Fe—C≡N —Co active sites was prepared by a nano-casting technique. Together with the high surface area and graphitization degree, the catalytic performance of Fe-Co-N-GC for oxygen reduction reaction (ORR) was remarkably enhanced. This Fe-Co-based bimetallic catalyst also exhibited superior durability and good tolerance to methanol in ORR.
Using special compound {[Co(bpy)2]3[Fe(CN) 6]2}[Fe(CN)6]1/3 as a precursor, an ordered mesoporous Fe-Co- N-doped graphite - based catalyst (Fe-Co-N-GC) with the embedding Fe—N, Co— N, and Fe—C≡N —Co active sites was prepared by a nano-casting technique. Together with the high surface area and graphitization degree, the catalytic performance of Fe-Co-N-GC for oxygen reduction reaction (ORR) was remarkably enhanced. This Fe-Co-based bimetallic catalyst also exhibited superior durability and good tolerance to methanol in ORR.
2022, 38(5): 941-950
doi: 10.11862/CJIC.2022.092
Abstract:
Coordination polymers usually have the characteristics of large specific surface area and easy control of structure, which can effectively adsorb and remove Cr(Ⅵ) in water. A copper-based coordination polymer: {[Cu(bipy)4 (1, 3-dab)][Cu(bipy)2(ClO4)2] (ClO4)2· (1, 3 - dab)}n (1), was successfully synthesized by the hydrothermal synthesis method using 4, 4'-bipyridine (bipy), 1, 3-isophthalonitrile (1, 3-dab), Cu(ClO4)2·6H2O as raw materials. The structure of 1 was characterized by IR, X-ray single-crystal diffraction, elemental analysis, and X-ray photoelectron spectroscopy. The results show that 1 belongs to the orthorhombic crystal system, P2221 space group, a=1.115 52(5) nm, b= 1.116 66(4) nm, c =3.116 84(15) nm, V=3.882 5(3) nm3. The performance study of adsorbing Cr(Ⅵ) showed that the optimal dosage of adsorbent 1 was 0.04 g·L-1. It had good adsorption performance and pH adaptability in a pH range of 1-9. The adsorption performance was the best when pH=5, and the adsorption capacity could achieve 250 mg·g-1. The ion coexistence experiments showed that the greater the ion concentration and the higher the valence, the more obvious their effect on the adsorption of Cr(Ⅵ) by 1, and the inhibition of anion was higher than that of metal cations, followed the order of PO43- > SO42- > CO32- > Cl- > HCO3- > NO3-. CCDC: 2114736.
Coordination polymers usually have the characteristics of large specific surface area and easy control of structure, which can effectively adsorb and remove Cr(Ⅵ) in water. A copper-based coordination polymer: {[Cu(bipy)4 (1, 3-dab)][Cu(bipy)2(ClO4)2] (ClO4)2· (1, 3 - dab)}n (1), was successfully synthesized by the hydrothermal synthesis method using 4, 4'-bipyridine (bipy), 1, 3-isophthalonitrile (1, 3-dab), Cu(ClO4)2·6H2O as raw materials. The structure of 1 was characterized by IR, X-ray single-crystal diffraction, elemental analysis, and X-ray photoelectron spectroscopy. The results show that 1 belongs to the orthorhombic crystal system, P2221 space group, a=1.115 52(5) nm, b= 1.116 66(4) nm, c =3.116 84(15) nm, V=3.882 5(3) nm3. The performance study of adsorbing Cr(Ⅵ) showed that the optimal dosage of adsorbent 1 was 0.04 g·L-1. It had good adsorption performance and pH adaptability in a pH range of 1-9. The adsorption performance was the best when pH=5, and the adsorption capacity could achieve 250 mg·g-1. The ion coexistence experiments showed that the greater the ion concentration and the higher the valence, the more obvious their effect on the adsorption of Cr(Ⅵ) by 1, and the inhibition of anion was higher than that of metal cations, followed the order of PO43- > SO42- > CO32- > Cl- > HCO3- > NO3-. CCDC: 2114736.
2022, 38(5): 951-958
doi: 10.11862/CJIC.2022.104
Abstract:
A mixed metal-organic framework (MOF(Ni, Co)) was synthesized through a simple one-pot solvothermal method, and was characterized through X-ray diffraction, FT-IR, scanning electron microscope, X-ray photoelectron spectroscopy, and N2 adsorption-desorption. The performance of the samples as supercapacitor electrode materials was further studied for the first time. The unique nano-flower -like structure of MOF(Ni1.2Co0.8) provides more electroactive sites and a shorter pathway for electron transfer and electrolyte diffusion, resulting in an excellent electrochemical performance with a high specific capacitance of 850 F·g-1 at 1 A·g-1. At the same time, this work shows that the MOF(Ni) electrode material doped with an appropriate amount of Co can facilitate the electron/ion transportation of the electrode, reduce the contact resistance between active material and electrolyte, increase the electrical conductivity, and enhance the electrochemical performance.
A mixed metal-organic framework (MOF(Ni, Co)) was synthesized through a simple one-pot solvothermal method, and was characterized through X-ray diffraction, FT-IR, scanning electron microscope, X-ray photoelectron spectroscopy, and N2 adsorption-desorption. The performance of the samples as supercapacitor electrode materials was further studied for the first time. The unique nano-flower -like structure of MOF(Ni1.2Co0.8) provides more electroactive sites and a shorter pathway for electron transfer and electrolyte diffusion, resulting in an excellent electrochemical performance with a high specific capacitance of 850 F·g-1 at 1 A·g-1. At the same time, this work shows that the MOF(Ni) electrode material doped with an appropriate amount of Co can facilitate the electron/ion transportation of the electrode, reduce the contact resistance between active material and electrolyte, increase the electrical conductivity, and enhance the electrochemical performance.
2022, 38(5): 959-968
doi: 10.11862/CJIC.2022.096
Abstract:
Based on the newly synthesized two-dimensional material MoSi2N 4 (MSN), we developed a series of doped models of MSN for first - principles calculations. Firstly, we calculated the electronic properties of intrinsic MSN, including its band structure and density of states. Then we investigated the effects of Cr, Sn, and Co- doping on the electronic and optical properties of MSN. Our work demonstrates that the Co-doped system exhibits the lowest formation energy among the three doped systems, which indicates that the Co-doped system is the most stable one. The calculations of band gaps show that although all three doped models decrease the band gap of intrinsic MSN, three doped systems exhibit three different electronic properties. The densities of state diagrams also show that the Cr-doped system and the Co-doped system both produce local spikes near conduction band minimum (CBM) and valence band maximum (VBM). Furthermore, the optical properties of the MSN have also been improved a lot after doping.
Based on the newly synthesized two-dimensional material MoSi2N 4 (MSN), we developed a series of doped models of MSN for first - principles calculations. Firstly, we calculated the electronic properties of intrinsic MSN, including its band structure and density of states. Then we investigated the effects of Cr, Sn, and Co- doping on the electronic and optical properties of MSN. Our work demonstrates that the Co-doped system exhibits the lowest formation energy among the three doped systems, which indicates that the Co-doped system is the most stable one. The calculations of band gaps show that although all three doped models decrease the band gap of intrinsic MSN, three doped systems exhibit three different electronic properties. The densities of state diagrams also show that the Cr-doped system and the Co-doped system both produce local spikes near conduction band minimum (CBM) and valence band maximum (VBM). Furthermore, the optical properties of the MSN have also been improved a lot after doping.
2022, 38(5): 969-976
doi: 10.11862/CJIC.2022.099
Abstract:
Bi9P2O18Cl crystals were prepared by the high-temperature molten salt method. Single-crystal X-ray diffraction data analyses demonstrated that Bi9P 2O18Cl can undergo a crystal-to-crystal phase transition from room temperature to low temperature. At room temperature, this compound (α-phase) crystallizes in monoclinic space group P21/m (11) with unit cell parameters a=1.149 10(7) nm, b =0.540 64(4) nm, c=1.463 69(9) nm, β =93.741(6)°, V= 0.907 38(10) nm3. And at 100 K, it (β-phase) crystallizes in monoclinic space group P21/n (14) with unit cell parameters a=1.790 56(4) nm, b=0.538 870(10) nm, c=1.915 57(4) nm, β=103.693(2)°, V=1.795 76(6) nm3. Additionally, high pure powder samples of Bi9P2 O18Cl were synthesized using solid -state reaction method, which exhibited promising performance in photocatalytic water splitting to produce H2, the H2 evolution rates reached 33.69 µmol·g-1·h-1. CCDC: 2128785, α-phase Bi9P2O18Cl; 2145491, β-phase Bi9P2O18Cl.
Bi9P2O18Cl crystals were prepared by the high-temperature molten salt method. Single-crystal X-ray diffraction data analyses demonstrated that Bi9P 2O18Cl can undergo a crystal-to-crystal phase transition from room temperature to low temperature. At room temperature, this compound (α-phase) crystallizes in monoclinic space group P21/m (11) with unit cell parameters a=1.149 10(7) nm, b =0.540 64(4) nm, c=1.463 69(9) nm, β =93.741(6)°, V= 0.907 38(10) nm3. And at 100 K, it (β-phase) crystallizes in monoclinic space group P21/n (14) with unit cell parameters a=1.790 56(4) nm, b=0.538 870(10) nm, c=1.915 57(4) nm, β=103.693(2)°, V=1.795 76(6) nm3. Additionally, high pure powder samples of Bi9P2 O18Cl were synthesized using solid -state reaction method, which exhibited promising performance in photocatalytic water splitting to produce H2, the H2 evolution rates reached 33.69 µmol·g-1·h-1. CCDC: 2128785, α-phase Bi9P2O18Cl; 2145491, β-phase Bi9P2O18Cl.
