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2023 Volume 38 Issue 1
2023, 39(1): 1-12
doi: 10.11862/CJIC.2022.268
Abstract:
Three new binuclear Ln-based complexes with the formula [Ln2(acac)2(L)2(C2H5OH)2] (Ln=Tb (1), Ho (2), Er (3); acac-=acetylacetonate) have been synthesized via the solvothermal method by using a polydentate Schiff base ligand (H2L=(E)-N'-(3-ethoxy-2-hydroxyb enzylidene)-3-hydroxypicolinohydrazide) reacting with Ln(acac)3·2H2O. Single-crystal X-ray structures reveal that complexes 1-3 are mainly composed of two LnⅢ ions, two acac- ions, two L2- ions, two C2H5OH molecules, and the two central LnⅢ ions are connected by two μ2-O atoms forming a"parallelogram-shaped"Ln2O2 core. The solid-state fluorescence property shows that the emission spectrum of complex 1 exhibited the characteristic emissions of TbⅢ ions under the excitation of 296 nm. For complex 1, four characteristic emission peaks were observed at 490, 545, 585, and 620 nm, corresponding to the transitions of TbⅢ ion from 5D4 to 7FJ (J=6, 5, 4, 3). In addition, the biological activity study shows that complexes 1-3 had stronger antibacterial activity than H2L and Ln(acac)3·2H2O. The interaction between complexes 1-3 and DNA was studied by ultraviolet spectroscopy, cyclic voltammetry, gel electrophoresis, and fluorescence spectroscopy. The results reveal that complexes 1-3 could bind to calf thymus DNA mainly by intercalation.
Three new binuclear Ln-based complexes with the formula [Ln2(acac)2(L)2(C2H5OH)2] (Ln=Tb (1), Ho (2), Er (3); acac-=acetylacetonate) have been synthesized via the solvothermal method by using a polydentate Schiff base ligand (H2L=(E)-N'-(3-ethoxy-2-hydroxyb enzylidene)-3-hydroxypicolinohydrazide) reacting with Ln(acac)3·2H2O. Single-crystal X-ray structures reveal that complexes 1-3 are mainly composed of two LnⅢ ions, two acac- ions, two L2- ions, two C2H5OH molecules, and the two central LnⅢ ions are connected by two μ2-O atoms forming a"parallelogram-shaped"Ln2O2 core. The solid-state fluorescence property shows that the emission spectrum of complex 1 exhibited the characteristic emissions of TbⅢ ions under the excitation of 296 nm. For complex 1, four characteristic emission peaks were observed at 490, 545, 585, and 620 nm, corresponding to the transitions of TbⅢ ion from 5D4 to 7FJ (J=6, 5, 4, 3). In addition, the biological activity study shows that complexes 1-3 had stronger antibacterial activity than H2L and Ln(acac)3·2H2O. The interaction between complexes 1-3 and DNA was studied by ultraviolet spectroscopy, cyclic voltammetry, gel electrophoresis, and fluorescence spectroscopy. The results reveal that complexes 1-3 could bind to calf thymus DNA mainly by intercalation.
2023, 39(1): 13-22
doi: 10.11862/CJIC.2022.259
Abstract:
The modified SiC particles prepared in the early stage with an environmentally benign method would be changed from hydrophilic to superhydrophobic with a contact angle of 156° after storing for a long time. To explain this new phenomenon, we tested and analyzed original, modified, and previously prepared materials of SiC powder with scanning electron microscope, energy spectrum, (high-resolution) transmission electron microscope, and X-ray photoelectron spectroscopy (XPS). The results showed that after being stored for a long time, the cell-like particles on the surface of SiC particles increased, and the bulges appeared to increase the roughness, which was similar to the micro-nano structures on the surface of lotus leaves. The main components of the modified particles were Ni, Si, and O, and the contents of Ni and O in the bulge were significantly higher than those in the depression. There was a clear film on the surface of Ni particles with a thickness of 2-3 nm, but their crystallinity was relatively low. The XPS test results showed that the characteristic peak of metallic nickel moves forward by nearly 4 eV, which is consistent with the characteristic peak of the nickel oxidation state. Small changes of morphology on particle surface are explained, which in turn explains the mechanism of spontaneous formation of the superhydrophobic film.
The modified SiC particles prepared in the early stage with an environmentally benign method would be changed from hydrophilic to superhydrophobic with a contact angle of 156° after storing for a long time. To explain this new phenomenon, we tested and analyzed original, modified, and previously prepared materials of SiC powder with scanning electron microscope, energy spectrum, (high-resolution) transmission electron microscope, and X-ray photoelectron spectroscopy (XPS). The results showed that after being stored for a long time, the cell-like particles on the surface of SiC particles increased, and the bulges appeared to increase the roughness, which was similar to the micro-nano structures on the surface of lotus leaves. The main components of the modified particles were Ni, Si, and O, and the contents of Ni and O in the bulge were significantly higher than those in the depression. There was a clear film on the surface of Ni particles with a thickness of 2-3 nm, but their crystallinity was relatively low. The XPS test results showed that the characteristic peak of metallic nickel moves forward by nearly 4 eV, which is consistent with the characteristic peak of the nickel oxidation state. Small changes of morphology on particle surface are explained, which in turn explains the mechanism of spontaneous formation of the superhydrophobic film.
2023, 39(1): 23-31
doi: 10.11862/CJIC.2022.257
Abstract:
The combination of photogenerated electron-hole pairs is considered one of the important reasons for limiting the photoelectrocatalytic conversion efficiency of BiVO4 photoanode. In this work, BiVO4/ZnFe2O4 homotypic heterojunction was constructed by a simple hydrothermal method and calcination process. The obtained BiVO4/ ZnFe2O4 photoanode achieved an excellent photocurrent density of 3.33 mA·cm-2 at 1.23 V (vs RHE), which was 2 times higher than that of pure BiVO4 (1.20 mA·cm-2). Related structure and performance tests showed that BiVO4 and ZnFe2O4 can form a bandgap staggered n-n heterojunction, which enables the photogenerated carriers to be effectively separated and participate in the water oxidation process, thus improving the photoelectrochemical water oxidation activities of BiVO4 photoanode.
The combination of photogenerated electron-hole pairs is considered one of the important reasons for limiting the photoelectrocatalytic conversion efficiency of BiVO4 photoanode. In this work, BiVO4/ZnFe2O4 homotypic heterojunction was constructed by a simple hydrothermal method and calcination process. The obtained BiVO4/ ZnFe2O4 photoanode achieved an excellent photocurrent density of 3.33 mA·cm-2 at 1.23 V (vs RHE), which was 2 times higher than that of pure BiVO4 (1.20 mA·cm-2). Related structure and performance tests showed that BiVO4 and ZnFe2O4 can form a bandgap staggered n-n heterojunction, which enables the photogenerated carriers to be effectively separated and participate in the water oxidation process, thus improving the photoelectrochemical water oxidation activities of BiVO4 photoanode.
2023, 39(1): 32-44
doi: 10.11862/CJIC.2022.264
Abstract:
Nitrogen-vacancies g-C3N5 (NVs) modified S-doping perylene diimide (S-PDI) organic compound semiconductor was prepared by electrostatic self-assembly. The nitrogen vacancies provided rich active sites on the surface of g-C3N5. The amide in the preparation of S-PDI enhanced the intermolecular interaction between S-PDI and NVs. The reduction rate of Cr(Ⅵ) over 30% NVs/S-PDI (with NVs mass fraction of 30%) was 79.96%, and the degradation rate of phenol was 74.40%. Furthermore, In the process of synergistic oxidation of phenol and reduction of Cr(Ⅵ) over 30% NVs/S-PDI, the reduction rate of Cr(Ⅵ) was 92.83%, and the degradation rate of phenol was 93.89%. Carboxylic acid and propanol, the products of oxidative degradation of phenol could be used as sacrificial agents of Cr(Ⅵ), which promoted the reduction of Cr(Ⅵ). The reduction of Cr(Ⅵ) enhanced the oxidative degradation of phenol. Accordingly, the carboxylic acid and propanol were finally oxidized to CO2 and H2O. Using the reduction performance of the conduction band and the oxidation performance of the valence band, the spatial separation of electrons and holes could be achieved by constructing heterojunction NVs/S-PDI, which could synergistically strengthen the oxidation half-reaction and reduction half-reaction in the photocatalytic process, simultaneously improve the photocatalytic oxidation-reduction performance. At the same time, under the illumination of visible light, H2O2 and Cr(Ⅵ)were generated in the phenol aqueous solution. A photo self-Fenton reaction process was formed by the electrons, H2O2 and Cr(Ⅵ), which further promoted the oxidative degradation of phenol and the reduction and removal of Cr(Ⅵ).
Nitrogen-vacancies g-C3N5 (NVs) modified S-doping perylene diimide (S-PDI) organic compound semiconductor was prepared by electrostatic self-assembly. The nitrogen vacancies provided rich active sites on the surface of g-C3N5. The amide in the preparation of S-PDI enhanced the intermolecular interaction between S-PDI and NVs. The reduction rate of Cr(Ⅵ) over 30% NVs/S-PDI (with NVs mass fraction of 30%) was 79.96%, and the degradation rate of phenol was 74.40%. Furthermore, In the process of synergistic oxidation of phenol and reduction of Cr(Ⅵ) over 30% NVs/S-PDI, the reduction rate of Cr(Ⅵ) was 92.83%, and the degradation rate of phenol was 93.89%. Carboxylic acid and propanol, the products of oxidative degradation of phenol could be used as sacrificial agents of Cr(Ⅵ), which promoted the reduction of Cr(Ⅵ). The reduction of Cr(Ⅵ) enhanced the oxidative degradation of phenol. Accordingly, the carboxylic acid and propanol were finally oxidized to CO2 and H2O. Using the reduction performance of the conduction band and the oxidation performance of the valence band, the spatial separation of electrons and holes could be achieved by constructing heterojunction NVs/S-PDI, which could synergistically strengthen the oxidation half-reaction and reduction half-reaction in the photocatalytic process, simultaneously improve the photocatalytic oxidation-reduction performance. At the same time, under the illumination of visible light, H2O2 and Cr(Ⅵ)were generated in the phenol aqueous solution. A photo self-Fenton reaction process was formed by the electrons, H2O2 and Cr(Ⅵ), which further promoted the oxidative degradation of phenol and the reduction and removal of Cr(Ⅵ).
2023, 39(1): 45-54
doi: 10.11862/CJIC.2022.263
Abstract:
A bottom-up approach was employed to build a thiazole-containing conjugated microporous polymer (NSCMP) by choosing bromo-thiazole and triacetylene benzene as monomers. The pyrolyzation and KOH-assisted pyrolyzation of NSCMP were performed to obtain the N, S heteroatom hard carbon (NSHC) and KOH-activated NSHC (KNSHC). NSHC and KNSHC were further characterized by scanning electronic microscope, energy-dispersive spectra (EDS), nitrogen adsorption-desorption, galvanostatic charge-discharging test, etc. The EDS revealed that the N and S mass fractions of KNSHC were 10.42% and 2.23%, respectively. The specific surface area of KNSHC was as high as 2 140 m2·g-1, which was distinctly higher than that of NSHC (657 m2·g-1). The specific capacity of KNSHC after 500 cycles at 0.2 A·g-1 was as high as 946.2 mAh·g-1, while that of NSHC was only 493.7 mAh·g-1. The excellent electrochemical performance of KNSHC may be due to the synergistic effect of N and S heteroatoms as well as the unique porous structure.
A bottom-up approach was employed to build a thiazole-containing conjugated microporous polymer (NSCMP) by choosing bromo-thiazole and triacetylene benzene as monomers. The pyrolyzation and KOH-assisted pyrolyzation of NSCMP were performed to obtain the N, S heteroatom hard carbon (NSHC) and KOH-activated NSHC (KNSHC). NSHC and KNSHC were further characterized by scanning electronic microscope, energy-dispersive spectra (EDS), nitrogen adsorption-desorption, galvanostatic charge-discharging test, etc. The EDS revealed that the N and S mass fractions of KNSHC were 10.42% and 2.23%, respectively. The specific surface area of KNSHC was as high as 2 140 m2·g-1, which was distinctly higher than that of NSHC (657 m2·g-1). The specific capacity of KNSHC after 500 cycles at 0.2 A·g-1 was as high as 946.2 mAh·g-1, while that of NSHC was only 493.7 mAh·g-1. The excellent electrochemical performance of KNSHC may be due to the synergistic effect of N and S heteroatoms as well as the unique porous structure.
2023, 39(1): 55-62
doi: 10.11862/CJIC.2022.258
Abstract:
To research the effect of different manganese sources on the prepared spinel LiMn2O4 (LMO), the precursors of the manganese sources were prepared by the precipitation method. And then, the most commonly used manganese oxides (MnO2, Mn2O3, and Mn3O4) were prepared by different calcination temperatures. The LMO cathode materials were prepared with manganese oxides under the same preparation conditions. And the relationship between manganese sources and the electrochemical performance of the obtained cathode materials was investigated by examining the morphology and electrochemical properties of LMO. The research result showed that different manganese oxides with different morphological structures can be obtained from the same precursor at different calcination temperatures. The morphology structures of LMOs and the contents and sizes of octahedral crystals were different. LMO prepared from Mn2O3 had the most octahedral crystals and the most uniform size. It also had the best capacity performance, rate performance, and cycle performance among the three LMOs: the first discharge-specific capacity was 131.8 mAh·g-1 (0.2C); the discharge-specific capacity of 100.4 mAh·g-1 at 3C; after 100 cycles at 0.5C (half-cell), the discharge specific capacity was still 116.0 mAh·g-1, and the capacity retention rate was 93.9%, which is far superior to the other two LMOs, indicating a good application prospect. Even at a high temperature of 55 ℃, LMO from Mn2O3 exhibited significantly higher rate performance and stronger anti-attenuation ability than the other two LMOs.
To research the effect of different manganese sources on the prepared spinel LiMn2O4 (LMO), the precursors of the manganese sources were prepared by the precipitation method. And then, the most commonly used manganese oxides (MnO2, Mn2O3, and Mn3O4) were prepared by different calcination temperatures. The LMO cathode materials were prepared with manganese oxides under the same preparation conditions. And the relationship between manganese sources and the electrochemical performance of the obtained cathode materials was investigated by examining the morphology and electrochemical properties of LMO. The research result showed that different manganese oxides with different morphological structures can be obtained from the same precursor at different calcination temperatures. The morphology structures of LMOs and the contents and sizes of octahedral crystals were different. LMO prepared from Mn2O3 had the most octahedral crystals and the most uniform size. It also had the best capacity performance, rate performance, and cycle performance among the three LMOs: the first discharge-specific capacity was 131.8 mAh·g-1 (0.2C); the discharge-specific capacity of 100.4 mAh·g-1 at 3C; after 100 cycles at 0.5C (half-cell), the discharge specific capacity was still 116.0 mAh·g-1, and the capacity retention rate was 93.9%, which is far superior to the other two LMOs, indicating a good application prospect. Even at a high temperature of 55 ℃, LMO from Mn2O3 exhibited significantly higher rate performance and stronger anti-attenuation ability than the other two LMOs.
2023, 39(1): 63-70
doi: 10.11862/CJIC.2022.271
Abstract:
A series of Eu2+ doped MgY2Al3Si2O11N (MYASON) cyan-emitting phosphors were synthesized by a high-temperature solid-state method. The effects of three preparation methods on the phase structure and luminous intensity of phosphor were discussed in detail. By comparing the XRD patterns and fluorescence intensity of samples, it was proved that H2/N2 as a reducing atmosphere was conducive to obtaining pure phase and good luminescence properties. X-ray diffraction refinement and X-ray photoelectron spectroscopy proved that Si4+-N3- ion pair was successfully doped into the garnet lattice. The emission spectrum of the sample showed asymmetric broadband emission at 420-750 nm. With the increase of Eu2+ doping concentration, the emission intensity of the phosphor was quenched by concentration. The quenching mechanism is electric multipole interaction. In addition, the thermal stability of the sample was studied by variable temperature spectrum, and its activation energy (ΔE) was calculated to be 0.22 eV. The results show that MYASON∶Eu2+ phosphor exhibited asymmetric broadband emission in the cyanemitting light region when excited by 365 nm ultraviolet light, and the peak value was 490 nm, which can effectively provide cyan-emitting light components for the white light emitting diode excited by the ultraviolet chip.
A series of Eu2+ doped MgY2Al3Si2O11N (MYASON) cyan-emitting phosphors were synthesized by a high-temperature solid-state method. The effects of three preparation methods on the phase structure and luminous intensity of phosphor were discussed in detail. By comparing the XRD patterns and fluorescence intensity of samples, it was proved that H2/N2 as a reducing atmosphere was conducive to obtaining pure phase and good luminescence properties. X-ray diffraction refinement and X-ray photoelectron spectroscopy proved that Si4+-N3- ion pair was successfully doped into the garnet lattice. The emission spectrum of the sample showed asymmetric broadband emission at 420-750 nm. With the increase of Eu2+ doping concentration, the emission intensity of the phosphor was quenched by concentration. The quenching mechanism is electric multipole interaction. In addition, the thermal stability of the sample was studied by variable temperature spectrum, and its activation energy (ΔE) was calculated to be 0.22 eV. The results show that MYASON∶Eu2+ phosphor exhibited asymmetric broadband emission in the cyanemitting light region when excited by 365 nm ultraviolet light, and the peak value was 490 nm, which can effectively provide cyan-emitting light components for the white light emitting diode excited by the ultraviolet chip.
2023, 39(1): 71-79
doi: 10.11862/CJIC.2022.265
Abstract:
As a kind of volatile toxic amines, organic small-molecule amines do great harm to human health. Therefore, the detection of organic small-molecule amines has attracted extensive attention. Lanthanide luminescence sensors stand out among all kinds of fluorescent sensors because of their easy synthesis, high biocompatibility, and high sensitivity. However, the large ion radius and unstable coordination configuration of lanthanide ions make it a challenge to achieve high-sensitivity luminescence detection of organic small-molecule amines in the solid state. The mononuclear lanthanide complex [Eu(L)3(H2O)2] (HL=(2Z)-1-(4-(bis(2-hydroxyethyl)amino)phenyl)-4, 4, 4-trifluoro-3-hydroxybut-2-en-1-one) with intraligand charge transfer (ILCT) properties was successfully constructed by the coordination of the mono-β-diketone ligand with the lanthanide ion europium by introducing the amine alcohol recognition group. The sensing study of the complex showed that [Eu(L)3(H2O)2] exhibited obvious luminescence enhancement response to small organic amines such as tripropylamine under weak nucleophilic action.
As a kind of volatile toxic amines, organic small-molecule amines do great harm to human health. Therefore, the detection of organic small-molecule amines has attracted extensive attention. Lanthanide luminescence sensors stand out among all kinds of fluorescent sensors because of their easy synthesis, high biocompatibility, and high sensitivity. However, the large ion radius and unstable coordination configuration of lanthanide ions make it a challenge to achieve high-sensitivity luminescence detection of organic small-molecule amines in the solid state. The mononuclear lanthanide complex [Eu(L)3(H2O)2] (HL=(2Z)-1-(4-(bis(2-hydroxyethyl)amino)phenyl)-4, 4, 4-trifluoro-3-hydroxybut-2-en-1-one) with intraligand charge transfer (ILCT) properties was successfully constructed by the coordination of the mono-β-diketone ligand with the lanthanide ion europium by introducing the amine alcohol recognition group. The sensing study of the complex showed that [Eu(L)3(H2O)2] exhibited obvious luminescence enhancement response to small organic amines such as tripropylamine under weak nucleophilic action.
2023, 39(1): 80-90
doi: 10.11862/CJIC.2022.255
Abstract:
The MoO2@nitrogen doped carbon composite (MoO2@CN) was designed via one-step calcination from dopamine, ammonium molybdate, and ammonium bicarbonate. Besides, MoO2@CN was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, etc. The MoO2@CN/PMS system could reach 99.2% degradation rate for carbamazepine (CBZ) in 12 min under pH of 6.5 and temperature at 25 ℃. Moreover, the apparent rate constant (kobs) of MoO2@CN was calculated to be 0.393 min-1, about 24.0 times higher than that of the commercial MoO2 (0.016 4 min-1), which is attributed that MoO2@CN possessed better conductivity and larger specific surface area. MoO2@CN was capable to degrade CBZ effectively in the pH range of 2.5-10.5, and also exhibited effective degradation performance for most dyes, phenolic compounds, antibiotics, and other pollutants. In addition, the total organic carbon (TOC) degradation rate of CBZ was as high as 74.0% within 60 min in the MoO2@CN/PMS system. Electron paramagnetic resonance (EPR) spectroscopy and quenching tests were applied to verify that SO4·- and ·OH played a major role in the MoO2@CN/PMS system. Interestingly, the degradation performance of CBZ was significantly enhanced with high kobs value of 1.25 min-1 when MoO2@CN was introduced into the Fe2+/PMS system, which was about 15.7 times proceeding that of the Fe2+/PMS system (0.079 7 min-1). The phenomenon is mainly ascribed that MoO2@CN significantly accelerates the transition from Fe3+ to Fe2+, resulting in more ·OH production.
The MoO2@nitrogen doped carbon composite (MoO2@CN) was designed via one-step calcination from dopamine, ammonium molybdate, and ammonium bicarbonate. Besides, MoO2@CN was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, etc. The MoO2@CN/PMS system could reach 99.2% degradation rate for carbamazepine (CBZ) in 12 min under pH of 6.5 and temperature at 25 ℃. Moreover, the apparent rate constant (kobs) of MoO2@CN was calculated to be 0.393 min-1, about 24.0 times higher than that of the commercial MoO2 (0.016 4 min-1), which is attributed that MoO2@CN possessed better conductivity and larger specific surface area. MoO2@CN was capable to degrade CBZ effectively in the pH range of 2.5-10.5, and also exhibited effective degradation performance for most dyes, phenolic compounds, antibiotics, and other pollutants. In addition, the total organic carbon (TOC) degradation rate of CBZ was as high as 74.0% within 60 min in the MoO2@CN/PMS system. Electron paramagnetic resonance (EPR) spectroscopy and quenching tests were applied to verify that SO4·- and ·OH played a major role in the MoO2@CN/PMS system. Interestingly, the degradation performance of CBZ was significantly enhanced with high kobs value of 1.25 min-1 when MoO2@CN was introduced into the Fe2+/PMS system, which was about 15.7 times proceeding that of the Fe2+/PMS system (0.079 7 min-1). The phenomenon is mainly ascribed that MoO2@CN significantly accelerates the transition from Fe3+ to Fe2+, resulting in more ·OH production.
2023, 39(1): 91-97
doi: 10.11862/CJIC.2022.270
Abstract:
Pervaporation (PV) has been favorably adopted in the industrial dehydration of various organic mixtures. In this work, mordenite membrane (MOR membrane) for PV dehydration of acetic acid was prepared by a two-stage varying temperature crystallization hydrothermal method from dilute synthesis solution with a high molar ratio of water to silica (nH2O/nSiO2). The effects of varying temperature crystallization time, nH2O/nSiO2, and the amount of fluorine ion on the morphology and separation performance of MOR membrane were investigated. The results showed that the above conditions have significant effects on the morphology, crystallinity, membrane thickness, and PV performance of the MOR membranes. The best performance MOR membrane was prepared at first-stage temperature (150 ℃, 18 h) and second-stage temperature (120 ℃, 6 h) with nH2O/nSiO2=60. The permeation flux and separation coefficient of the mass fraction of 50% acetic acid aqueous solution were 1.45 kg·m-2·h-1 and 1 008, respectively.
Pervaporation (PV) has been favorably adopted in the industrial dehydration of various organic mixtures. In this work, mordenite membrane (MOR membrane) for PV dehydration of acetic acid was prepared by a two-stage varying temperature crystallization hydrothermal method from dilute synthesis solution with a high molar ratio of water to silica (nH2O/nSiO2). The effects of varying temperature crystallization time, nH2O/nSiO2, and the amount of fluorine ion on the morphology and separation performance of MOR membrane were investigated. The results showed that the above conditions have significant effects on the morphology, crystallinity, membrane thickness, and PV performance of the MOR membranes. The best performance MOR membrane was prepared at first-stage temperature (150 ℃, 18 h) and second-stage temperature (120 ℃, 6 h) with nH2O/nSiO2=60. The permeation flux and separation coefficient of the mass fraction of 50% acetic acid aqueous solution were 1.45 kg·m-2·h-1 and 1 008, respectively.
2023, 39(1): 98-108
doi: 10.11862/CJIC.2022.281
Abstract:
Oxygen vacancies construction and metallic Bi0 loading were proven effective ways for enhancing the light absorption performance of semiconductor materials and promoting the separation of photogenerated carriers. In this work, metal Bi (Bi0) decorated PO43- doped Bi2O2CO3 (BOC) nanocomposites (Bi-P-BOC) was successfully prepared through a simple co-precipitation method with a subsequent thermal reduction process, and its photocatalytic degradation mechanism of ofloxacin (OFX) under visible light irradiation was studied. The result demonstrated that PO43- was uniformly doped in BOC, which showed increased visible light response range, increased surface defects, and enlarged specific surface area. Through the thermal reduction process, a number of oxygen vacancies were produced as well as the loading of Bi0 on the surface of BOC. Bi-P-BOC was able to degrade 85% of the OFX in 180 min under visible light with a degradation rate of 0.013 0 min-1, which was about eight times than pristine BOC and about two times than P-BOC-6. The UV-visible diffuse reflectance spectroscopy spectrum showed the enhanced visible light absorption attribute to the surface plasmon resonance effect of Bi0. The improved separation of the photoinduced electron and hole pairs were confirmed by the photoluminescence spectrum. Thus, the enhanced photocatalysis performance of Bi-P-BOC may mainly be benefited from its increased visible light response range and improved separation of the photoinduced electron and hole pairs. Furthermore, h+ was detected to be the main reactive oxygen species (ROS) species for the degradation of OFX in this system, 1O2 and ·O2- also made contributions to the degradation.
Oxygen vacancies construction and metallic Bi0 loading were proven effective ways for enhancing the light absorption performance of semiconductor materials and promoting the separation of photogenerated carriers. In this work, metal Bi (Bi0) decorated PO43- doped Bi2O2CO3 (BOC) nanocomposites (Bi-P-BOC) was successfully prepared through a simple co-precipitation method with a subsequent thermal reduction process, and its photocatalytic degradation mechanism of ofloxacin (OFX) under visible light irradiation was studied. The result demonstrated that PO43- was uniformly doped in BOC, which showed increased visible light response range, increased surface defects, and enlarged specific surface area. Through the thermal reduction process, a number of oxygen vacancies were produced as well as the loading of Bi0 on the surface of BOC. Bi-P-BOC was able to degrade 85% of the OFX in 180 min under visible light with a degradation rate of 0.013 0 min-1, which was about eight times than pristine BOC and about two times than P-BOC-6. The UV-visible diffuse reflectance spectroscopy spectrum showed the enhanced visible light absorption attribute to the surface plasmon resonance effect of Bi0. The improved separation of the photoinduced electron and hole pairs were confirmed by the photoluminescence spectrum. Thus, the enhanced photocatalysis performance of Bi-P-BOC may mainly be benefited from its increased visible light response range and improved separation of the photoinduced electron and hole pairs. Furthermore, h+ was detected to be the main reactive oxygen species (ROS) species for the degradation of OFX in this system, 1O2 and ·O2- also made contributions to the degradation.
2023, 39(1): 109-116
doi: 10.11862/CJIC.2022.261
Abstract:
A simple one-pot method was used to prepare the Se doped WO3·0.5H2O/g-C3N4 (Se/WCN) electrocatalyst. The crystal phase structure, morphology, and chemical composition were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical performance was measured by linear sweep voltammetry, electrochemical impedance, and chronoamperometry in 1 mol·L-1 H2SO4 solution. The results showed that the prepared Se/WCN-1 had the best electrochemical performance when the mass ratio of Se doping to g-C3N4 was 1∶1, and the overpotential was -0.75 V (vs RHE) at the current density of 70 mA·cm-2. After exposure to light, the initial potential of Se/WCN-1 decreased from -0.75 to -0.65 V (vs RHE), and charge-transfer resistance decreased from 371.4 to 310.0 Ω.
A simple one-pot method was used to prepare the Se doped WO3·0.5H2O/g-C3N4 (Se/WCN) electrocatalyst. The crystal phase structure, morphology, and chemical composition were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and X-ray photoelectron spectroscopy (XPS). The electrochemical performance was measured by linear sweep voltammetry, electrochemical impedance, and chronoamperometry in 1 mol·L-1 H2SO4 solution. The results showed that the prepared Se/WCN-1 had the best electrochemical performance when the mass ratio of Se doping to g-C3N4 was 1∶1, and the overpotential was -0.75 V (vs RHE) at the current density of 70 mA·cm-2. After exposure to light, the initial potential of Se/WCN-1 decreased from -0.75 to -0.65 V (vs RHE), and charge-transfer resistance decreased from 371.4 to 310.0 Ω.
2023, 39(1): 117-126
doi: 10.11862/CJIC.2022.282
Abstract:
Two complexes [Ca(Phen)(Nap)2]n (1) and [Mn2(Phen)2(Nap)4(H2O)] (2) were synthesized by calcium acetate monohydrate or manganous acetate reacting with 1, 10-phenanthroline (Phen) and 1-naphthoic acid (HNap). Complexes 1 and 2 have been characterized by IR, elemental analysis, and thermogravimetry and the crystal structures have been determined by X-ray diffraction. Both the central calcium ion and the central manganese ion form a six-coordinated twisted octahedral structure. The excitation spectrum and emission spectrum of the two complexes were determined, and the results showed that the excitation and emission spectra of the complexes had a good mirror relationship, and the Stokes shift of complex 2 was greater than that of complex 1. In vitro antitumor activities of both complexes were evaluated by MTT against three human cancer cell lines, namely human lung cancer cells (NCI-H460), human breast cancer cells (MCF-7), human liver cancer cells (HepG2), and human normal cells (HL7702). It was found that complexes 1 and 2 showed a good inhibitory effect on the three cancer cells, compared to the normal cell. The interactions of the complexes with calf thymus DNA have been studied by UV and fluorescence spectroscopy, and the results show that the binding mode of complexes 1 and 2 with DNA may most likely bind in the groove of the DNA backbone by electrostatic action, and their intrinsic binding constants were 5.83×103 and 6.43×103 L·mol-1, respectively. Complex 1 showed no redshift, while complex 2 showed an obvious redshift of 2.0 nm. The subtractive effect, intrinsic binding constants, and the redshift data indicate that the interaction between complex 2 and DNA is greater than that between complex 1 and DNA.
Two complexes [Ca(Phen)(Nap)2]n (1) and [Mn2(Phen)2(Nap)4(H2O)] (2) were synthesized by calcium acetate monohydrate or manganous acetate reacting with 1, 10-phenanthroline (Phen) and 1-naphthoic acid (HNap). Complexes 1 and 2 have been characterized by IR, elemental analysis, and thermogravimetry and the crystal structures have been determined by X-ray diffraction. Both the central calcium ion and the central manganese ion form a six-coordinated twisted octahedral structure. The excitation spectrum and emission spectrum of the two complexes were determined, and the results showed that the excitation and emission spectra of the complexes had a good mirror relationship, and the Stokes shift of complex 2 was greater than that of complex 1. In vitro antitumor activities of both complexes were evaluated by MTT against three human cancer cell lines, namely human lung cancer cells (NCI-H460), human breast cancer cells (MCF-7), human liver cancer cells (HepG2), and human normal cells (HL7702). It was found that complexes 1 and 2 showed a good inhibitory effect on the three cancer cells, compared to the normal cell. The interactions of the complexes with calf thymus DNA have been studied by UV and fluorescence spectroscopy, and the results show that the binding mode of complexes 1 and 2 with DNA may most likely bind in the groove of the DNA backbone by electrostatic action, and their intrinsic binding constants were 5.83×103 and 6.43×103 L·mol-1, respectively. Complex 1 showed no redshift, while complex 2 showed an obvious redshift of 2.0 nm. The subtractive effect, intrinsic binding constants, and the redshift data indicate that the interaction between complex 2 and DNA is greater than that between complex 1 and DNA.
2023, 39(1): 127-134
doi: 10.11862/CJIC.2022.260
Abstract:
Compared with anhydrous WO3, tungsten oxide dihydrate (WO3·2H2O) shows superior electrochromic properties because of its unique layered structure and rich interlayer structural water. In this study, WO3·2H2O films were successfully fabricated on indium tin oxide (ITO) glass substrates using a facile, template-free cathodic electrodeposition method. The composition of the electrodeposition solution was optimized by modifying the volume of hydrogen peroxide (H2O2) added into the solution, and thus highly porous films were obtained. The thus deposited WO3·2H2O films exhibited excellent electrochromic performance, including significant optical contrast of over 90% at 633 nm, a fast switching speed of fewer than 10 s, and a long cycling lifetime (90% original optical modulation was retained after 10 000 cycles).
Compared with anhydrous WO3, tungsten oxide dihydrate (WO3·2H2O) shows superior electrochromic properties because of its unique layered structure and rich interlayer structural water. In this study, WO3·2H2O films were successfully fabricated on indium tin oxide (ITO) glass substrates using a facile, template-free cathodic electrodeposition method. The composition of the electrodeposition solution was optimized by modifying the volume of hydrogen peroxide (H2O2) added into the solution, and thus highly porous films were obtained. The thus deposited WO3·2H2O films exhibited excellent electrochromic performance, including significant optical contrast of over 90% at 633 nm, a fast switching speed of fewer than 10 s, and a long cycling lifetime (90% original optical modulation was retained after 10 000 cycles).
2023, 39(1): 135-140
doi: 10.11862/CJIC.2022.276
Abstract:
Two ternary lanthanide complexes, [Eu(L)3(Phen)]2·2H2O (1) and [Tb(L)3(Phen)]2·2H2O (2), based on 3-((4, 6-dimethyl-2-pyrimidinyl)thio)-propanoic acid (HL) and 1, 10-phenanthroline (Phen) were prepared and structurally characterized. Single-crystal X-ray diffraction analyses reveal that they are isostructural. Two lanthanide ions (Ln) are bridged by four carboxylate ligands. The rest two carboxylate ligands and Phen coordinate with Ln with bidentate chelating mode, forming the dimeric arrangement. The coordination number of Ln is nine with a distorted mono-capped square antiprismatic coordination polyhedron. The solid-state photoluminescent measurements suggest that both complexes showcase the characteristic emission bands of the metal center.
Two ternary lanthanide complexes, [Eu(L)3(Phen)]2·2H2O (1) and [Tb(L)3(Phen)]2·2H2O (2), based on 3-((4, 6-dimethyl-2-pyrimidinyl)thio)-propanoic acid (HL) and 1, 10-phenanthroline (Phen) were prepared and structurally characterized. Single-crystal X-ray diffraction analyses reveal that they are isostructural. Two lanthanide ions (Ln) are bridged by four carboxylate ligands. The rest two carboxylate ligands and Phen coordinate with Ln with bidentate chelating mode, forming the dimeric arrangement. The coordination number of Ln is nine with a distorted mono-capped square antiprismatic coordination polyhedron. The solid-state photoluminescent measurements suggest that both complexes showcase the characteristic emission bands of the metal center.
2023, 39(1): 141-149
doi: 10.11862/CJIC.2022.272
Abstract:
A binuclear monofunctional platinum(Ⅱ) complex, [Pt2(BPA-TPA)Cl2]Cl2 (Pt2-BPA-TPA), containing polypyridyl ligand 2, 6-bis((bis(pyridin-2-ylmethyl)amino)methyl)pyridine was synthesized and characterized by nuclear magnetic resonance and high-resolution mass spectroscopy. In addition, the structure of Pt2-BPA-TPA was determined by X-ray single-crystal diffraction. Agarose gel electrophoresis experiments were used to demonstrate the efficient pBR322 DNA-cleaving activity of Pt2-BPA-TPA at a low concentration of 10 μmol·L-1. In CCK-8 (cell counting kit-8) cytotoxicity studies using the A549 human lung cancer cell line, Pt2-BPA-TPA demonstrated enhanced anticancer activity compared with cisplatin. Mechanistic studies provided evidence that Pt2-BPA-TPA induces apoptosis via triggering DNA damage and upregulating downstream cellular signaling cascades of p21 and cleaved-caspase-3.
A binuclear monofunctional platinum(Ⅱ) complex, [Pt2(BPA-TPA)Cl2]Cl2 (Pt2-BPA-TPA), containing polypyridyl ligand 2, 6-bis((bis(pyridin-2-ylmethyl)amino)methyl)pyridine was synthesized and characterized by nuclear magnetic resonance and high-resolution mass spectroscopy. In addition, the structure of Pt2-BPA-TPA was determined by X-ray single-crystal diffraction. Agarose gel electrophoresis experiments were used to demonstrate the efficient pBR322 DNA-cleaving activity of Pt2-BPA-TPA at a low concentration of 10 μmol·L-1. In CCK-8 (cell counting kit-8) cytotoxicity studies using the A549 human lung cancer cell line, Pt2-BPA-TPA demonstrated enhanced anticancer activity compared with cisplatin. Mechanistic studies provided evidence that Pt2-BPA-TPA induces apoptosis via triggering DNA damage and upregulating downstream cellular signaling cascades of p21 and cleaved-caspase-3.
2023, 39(1): 150-158
doi: 10.11862/CJIC.2022.280
Abstract:
To explore the potential applications of AlN in optoelectronic devices, the electronic structure and optical properties of AlN with different Lu doping concentrations (denoted as Al1-xLuxN, where x is the atomic fraction of Lu) were calculated by first-principles. The results show that the supercell volume of Al1-xLuxN increases with the increase of Lu doping concentration, while the bandgap does the opposite. The static dielectric constant of Al1-xLuxN increases in the low-energy region with the increase of Lu doping concentration. As Lu doping concentration increases, the peak intensity of reflectivity, refractive index, and absorption coefficient decrease, and the peaks shift to lower energy. The energy-loss spectra of Al1-xLuxN exhibit obvious plasma oscillation features, and the peaks are lower than that of the intrinsic AlN. The photoconductivity of Al1-xLuxN increases sharply in the low-energy region with the increase of energy.
To explore the potential applications of AlN in optoelectronic devices, the electronic structure and optical properties of AlN with different Lu doping concentrations (denoted as Al1-xLuxN, where x is the atomic fraction of Lu) were calculated by first-principles. The results show that the supercell volume of Al1-xLuxN increases with the increase of Lu doping concentration, while the bandgap does the opposite. The static dielectric constant of Al1-xLuxN increases in the low-energy region with the increase of Lu doping concentration. As Lu doping concentration increases, the peak intensity of reflectivity, refractive index, and absorption coefficient decrease, and the peaks shift to lower energy. The energy-loss spectra of Al1-xLuxN exhibit obvious plasma oscillation features, and the peaks are lower than that of the intrinsic AlN. The photoconductivity of Al1-xLuxN increases sharply in the low-energy region with the increase of energy.
2023, 39(1): 159-167
doi: 10.11862/CJIC.2022.277
Abstract:
The organic substance 2,5-dibromoterephthalic acid (H2L1) was used as the primary ligand and 2,2'-bipyridine (L2) and 1,10-phenanthroline (L3) as the secondary ligands, respectively, and reacted with manganese sulphate monohydrate and cobalt nitrate hexahydrate by the solvothermal method to give complexes [Mn2(L1)2(L2)2 (H2O)2]n (1) and [Co2(L1)2(L3)2(H2O)2]n (2). The two complexes were investigated analytically by such as single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis, etc. The results show that complex 1 is composed of Mn2+ coordination linking L12- and L2 to form an infinitely extended 2D network-like structure, with the layers forming a 3D network-like structure under intermolecular hydrogen bonding and π-π stacking. Complex 2 consists of Co2+ ligated to L12- and L3 to form an infinitely extended 2D network, with the layers stacked in a 3D network by intermolecular hydrogen bonding and π -π stacking. Both complexes had good fluorescence property and thermal stability, and the maximum emission wavelengths of complexes 1 and 2 were 355 and 365 nm, respectively.
The organic substance 2,5-dibromoterephthalic acid (H2L1) was used as the primary ligand and 2,2'-bipyridine (L2) and 1,10-phenanthroline (L3) as the secondary ligands, respectively, and reacted with manganese sulphate monohydrate and cobalt nitrate hexahydrate by the solvothermal method to give complexes [Mn2(L1)2(L2)2 (H2O)2]n (1) and [Co2(L1)2(L3)2(H2O)2]n (2). The two complexes were investigated analytically by such as single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis, etc. The results show that complex 1 is composed of Mn2+ coordination linking L12- and L2 to form an infinitely extended 2D network-like structure, with the layers forming a 3D network-like structure under intermolecular hydrogen bonding and π-π stacking. Complex 2 consists of Co2+ ligated to L12- and L3 to form an infinitely extended 2D network, with the layers stacked in a 3D network by intermolecular hydrogen bonding and π -π stacking. Both complexes had good fluorescence property and thermal stability, and the maximum emission wavelengths of complexes 1 and 2 were 355 and 365 nm, respectively.
2023, 39(1): 168-180
doi: 10.11862/CJIC.2022.273
Abstract:
Two cadmium-based coordination polymers [Cd(Htatb) (1,4-bimb)] ·H2O (1) and [Cd(Htatb) (1,4-bib) (H2O)]·DMF (2) (H3tatb=4, 4', 4″-s-triazine-2,4,6-tribenzoic acid, 1,4-bimb=1,4-bis(imidazole-1-ylmethyl) benzene, 1,4-bib=1,4-bis(1-imidazoly) benzene) were synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction, thermogravimetric analyses, IR spectroscopy, elemental analysis, etc. 1 displays a 2D layer structure, further these layers are joined by O—H⋯O hydrogen bonding to generate a four-fold interpenetrating 3D architecture. 2 shows a 2D layer structure, further joined through O—H⋯O hydrogen bonding to produce a two-fold interpenetrating 3D architecture. Complexes 1 and 2 had fluorescent properties. 1 was highly selective and sensitive towards nitrobenzene and Fe3+ ion through different detection mechanisms, while CP 2 was highly selective and sensitive towards 2,4,6-trinitrophenol and CrO42- ion.
Two cadmium-based coordination polymers [Cd(Htatb) (1,4-bimb)] ·H2O (1) and [Cd(Htatb) (1,4-bib) (H2O)]·DMF (2) (H3tatb=4, 4', 4″-s-triazine-2,4,6-tribenzoic acid, 1,4-bimb=1,4-bis(imidazole-1-ylmethyl) benzene, 1,4-bib=1,4-bis(1-imidazoly) benzene) were synthesized by hydrothermal reactions and characterized by single-crystal X-ray diffraction, thermogravimetric analyses, IR spectroscopy, elemental analysis, etc. 1 displays a 2D layer structure, further these layers are joined by O—H⋯O hydrogen bonding to generate a four-fold interpenetrating 3D architecture. 2 shows a 2D layer structure, further joined through O—H⋯O hydrogen bonding to produce a two-fold interpenetrating 3D architecture. Complexes 1 and 2 had fluorescent properties. 1 was highly selective and sensitive towards nitrobenzene and Fe3+ ion through different detection mechanisms, while CP 2 was highly selective and sensitive towards 2,4,6-trinitrophenol and CrO42- ion.
2023, 39(1): 181-190
doi: 10.11862/CJIC.2022.278
Abstract:
Two Mg-based metal-organic frameworks (MOFs) were prepared using a coordination competition strategy. Under acidic conditions, the reaction of Mg(Ⅱ) ions with formic acid generated from the thermal decomposition of N, N-dimethylformamide (DMF) formed a 3D formate Mg-MOF: [Mg3(HCO2)6]·DMF (1). However, under the same conditions but with a competing ligand 1,1'∶3',1″-terphenyl-3,3″,5, 5″-tetracarboxylic acid (H4L), formic acid was no longer involved in the coordination, resulting in a new 3D Mg-MOF: [Mg2(L) (H2O)3]·2H2O·2CH3CN·DMF (2). Single-crystal X-ray analysis revealed that 1 possesses [Mg4@Mg2] tetrahedral building units that form a dia topological network with a 1D channel size of 0.44 nm. In contrast, 2 has a unique [Mg2] binuclear cluster to build a sra topology network after bridging the 4-connected L4- linker. Interestingly, a dumbbell-shaped pore with a length of 1.42 nm is observed along the a-axis in 2. Gas adsorption studies reveal that 1 had a significantly accessible inner surface with a surface area of 342 m2·g-1. However, after solvent removal, 2 could not retain the original porous character. Featuring good water stability, 1 exhibited a type-Ⅰ CO2 adsorption isotherm with quick uptake at low pressure, and up to 14.5% of the sample weight at 298 K and 2 000 kPa. Ideal adsorption solution theory (IAST) and adsorption heat calculations show that 1 has a good ability for selective CO2 capture from CH4 contained mixture.
Two Mg-based metal-organic frameworks (MOFs) were prepared using a coordination competition strategy. Under acidic conditions, the reaction of Mg(Ⅱ) ions with formic acid generated from the thermal decomposition of N, N-dimethylformamide (DMF) formed a 3D formate Mg-MOF: [Mg3(HCO2)6]·DMF (1). However, under the same conditions but with a competing ligand 1,1'∶3',1″-terphenyl-3,3″,5, 5″-tetracarboxylic acid (H4L), formic acid was no longer involved in the coordination, resulting in a new 3D Mg-MOF: [Mg2(L) (H2O)3]·2H2O·2CH3CN·DMF (2). Single-crystal X-ray analysis revealed that 1 possesses [Mg4@Mg2] tetrahedral building units that form a dia topological network with a 1D channel size of 0.44 nm. In contrast, 2 has a unique [Mg2] binuclear cluster to build a sra topology network after bridging the 4-connected L4- linker. Interestingly, a dumbbell-shaped pore with a length of 1.42 nm is observed along the a-axis in 2. Gas adsorption studies reveal that 1 had a significantly accessible inner surface with a surface area of 342 m2·g-1. However, after solvent removal, 2 could not retain the original porous character. Featuring good water stability, 1 exhibited a type-Ⅰ CO2 adsorption isotherm with quick uptake at low pressure, and up to 14.5% of the sample weight at 298 K and 2 000 kPa. Ideal adsorption solution theory (IAST) and adsorption heat calculations show that 1 has a good ability for selective CO2 capture from CH4 contained mixture.
