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Showing papers in "Chinese Journal of Chemistry in 2012"


Journal ArticleDOI
Mingyi Guo1, Aifei Wang1, Faheem Muhammad1, Wenxiu Qi1, Hao Ren1, Yingjie Guo1, Guangshan Zhu1 
TL;DR: In this paper, multi-component halloysite nanotubes (HNTs) have been evaluated as a platform to assist and direct the delivery of anticancer drug doxorubicin (DOX) into cancer cells.
Abstract: Targeted drug delivery systems have attracted a great deal of interest by virtue of their potential use in chemotherapy. In this study, multicomponent halloysite nanotubes (HNTs) have been evaluated as a platform to assist and direct the delivery of anticancer drug doxorubicin (DOX) into cancer cells. Folic acid (FA) and magnetite nanoparticles were successfully grafted onto HNTs via amide reaction whereas the drug has been introduced by capitalizing electrostatic interaction between cationic drug and anionic exterior of HNTs, which eventually leads to pH responsive release. The resultant DOX loaded FA-Fe3O4@HNTs were well characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and XRD. The clinical efficacy of the system was validated by confocal microscopy and cell cytotoxicity assay (MTT assay). MTT assay results revealed a high biocompatibility up to a concentration of 200 µg/mL of HNTs, while, DOX loaded FA-Fe3O4@HNTs were markedly cytotoxic to HeLa cells. This multifunctional nanovehicle has a great potential for cancer diagnosis and therapy, and could further advance the clinical use of nanomedicine.

50 citations


Journal ArticleDOI
Gaigai Liang1, Miaochang Liu1, Jiuxi Chen1, Jinchang Ding1, Wenxia Gao1, Huayue Wu1 
TL;DR: In this paper, a highly practical method to access unsymmetrical and symmetrical thiosulfonates in moderate to excellent yields has been developed through NBS-promoted sulfenylation of sulfinates with disulfides.
Abstract: A highly practical method to access unsymmetrical and symmetrical thiosulfonates in moderate to excellent yields has been developed through NBS-promoted sulfenylation of sulfinates with disulfides. The present process enables the use of two RS in RSSR and shows broad functional group tolerance, which represents an atom-economical and practical procedure for the synthesis of thiosulfonates. A plausible mechanism for the role of NBS as a promoter for the cleavage of disul?des generating N-(organothio)succinimide that then undergos facile sulenylation with sulfinates is proposed.

47 citations


Journal ArticleDOI
TL;DR: In this article, the zeolitic imidazolate framework-8 (ZIF-8) was successfully synthesized using ionic liquids as structure-directing agent under microwave irradiation.
Abstract: The zeolitic imidazolate framework-8 (ZIF-8) was successfully synthesized using ionic liquids as structure-directing agent under microwave irradiation. Ionic liquids are green solvents with low vapour pressure and good thermal stability. They are appropriate templates for microporous materials and ideal microwave absorbers. The microwave-assisted ionothermal synthesis applied in this paper was expected to be a promising method for the preparation of microporous materials. Results showed that the as-synthesized samples (300–500 nm in diameter) could be synthesized in a short time (60 min) and possessed regular morphology, stable structure and high thermal stability (up to 720°C in argon atmosphere). Nitrogen adsorption-desorption test illustrated that samples produced by microwave heating had a higher surface area. Carbon dioxide adsorption test indicated that the samples synthesized by microwave heating had better carbon dioxide adsorption ability than those by conventional heating.

47 citations


Journal ArticleDOI
TL;DR: In this paper, the photocatalytic activity of the produced bismuth oxybromides was evaluated under both visible light (λ>420 nm) and UV-light (λ=365 nm) irradiation.
Abstract: Flake BiOBr was first prepared by a solution method at room temperature. Then, the produced BiOBr was calcined at different temperatures. It was found that BiOBr is not a stable compound. It transforms to plate-like Bi24O31Br11at around 750°C and the formed Bi24O31Br11 can further convert to rod-like α-Bi2O3 at around 850°C. The prepared compounds were characterized with X-ray diffraction (XRD), N2 physical adsorption, scanning electron microscopy (SEM), and UV-Vis diffuse reflectance spectra (DRS), respectively. The photocatalytic activity of the produced bismuth oxybromides was evaluated by photocatalytic decomposition of acid orange II under both visible light (λ>420 nm) and UV light (λ=365 nm) irradiation. Results show that these compounds have different band gaps and different photocatalytic properties. The band gap energies of the as-prepared samples were found to be 2.82, 2.79, 2.60 and 3.15 eV for BiOBr, BiOBr/Bi24O31Br, Bi24O31Br, and α-Bi2O3, respectively. Under both UV light and visible light irradiation, the photocatalytic activity follows the order: BiOBr/Bi24O31Br mixture>BiOBr>Bi24O31Br>α-Bi2O3. The change in photocatalytic activity could be attributed to the different light absorption ability and microstructures of the photocatalysts.

44 citations


Journal ArticleDOI
TL;DR: In this article, the Williamson reaction of 4-hydroxycoumarin with α-haloketones followed by cyclization was used to synthesize 2,3-dimethyl-4H-furo[3,2-c] coumarins.
Abstract: Syntheses of 2,3-dimethyl-4H-furo[3,2-c]coumarin and 3-phenyl-4H-furo[3,2-c]coumarin as angular furocoumarins were carried out through Williamson reaction of 4-hydroxycoumarin with α-haloketones followed by cyclization. Photooxygenation of the synthesized furocoumarin derivatives was performed and the photoproducts were isolated and characterized. The affinity of 2,3-dimethyl-4H-furo[3,2-c]coumarin towards DNA and the antibacterial activity were evaluated and compared with 8-methoxypsoralen (8-MOP).

42 citations


Journal ArticleDOI
TL;DR: In this paper, a quaternary phosphonium-based polyelectrolyte was synthesized from bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) by functionalization with tris (2,4, 6-trimethoxyphenyl) phosphine (TTMPP).
Abstract: Quaternary phosphonium-based polyelectrolyte was synthesized from bromomethylated poly(2,6-dimethyl-1,4- phenylene oxide) (BPPO) by functionalization with tris(2,4,6-trimethoxyphenyl) phosphine (TTMPP). Typically, excellent solubility of the polyelectrolyte in polar solvents, such as NMP and DMSO, allowed a solution-casting strategy for preparation of anion exchange membrane (AEM) with properly ordered hydrophilic/hydrophobic nano-scale phase separation morphology, which was visible in atomic force microscopic phase images. Accordingly, the optimized ionmeric AEM exhibited excellent hydroxide conductivity of 110 mS/cm at 70°C, but extremely restricted linear expansion ratio of below 7% at the same temperature. Additionally, such membrane could maintain flexibility and conductivity after an immersion treatment in 1 mol/L NaOH solution at 60°C for about 100 h, implying its potential in alkaline fuel cells.

40 citations


Journal ArticleDOI
TL;DR: In this article, the diffusion of Vitamin C (VC) in water solution was examined by molecular dynamics simulation and the diffusion coefficients were calculated based on the Einstein equation and the influences of temperature, concentration, and simulation time on the diffusion coefficient were discussed.
Abstract: Under different temperatures and concentrations, the diffusion of Vitamin C (VC) in water solution was examined by molecular dynamics simulation. The diffusion coefficients were calculated based on the Einstein equation. The influences of temperature, concentration, and simulation time on the diffusion coefficient were discussed. The results showed that at higher temperature and lower concentration the normal diffusions appear relatively late, but the linear range of mean square displacement curves continues longer than that at lower temperature and higher concentration. At the same temperature, the normal diffusion time increases and the diffusion coefficient decreases as the simulation concentration increases. These simulation results are in good agreement with experiments. Analyses of the pair correlation functions of the simulation systems showed that hydrogen bonds are mainly formed between the hydrogen atoms of VC molecules and oxygen atoms of H2O molecules, rather than between the O atoms of VC molecules and H atoms of H2O molecules. The diffusion coefficient is higher as the interaction between water molecules and VC molecules is stronger when VC concentration is lower. The water in the model systems affects the diffusion of VC molecules by the short-range repulsion of O(H2O)-O(H2O) pairs and the non-bond interaction of H(H2O)-H(H2O) pairs. The short-range repulsion of O(H2O)-O(H2O) pairs is greater when VC concentration is higher, the diffusion of VC is weaker. The greater the non-bond interaction of H(H2O)-H(H2O) pairs is, the higher the VC diffusion is. It is expected that this study can provide a theoretical direction for the experiments on the mass transfer of VC in water solution.

37 citations


Journal ArticleDOI
TL;DR: In this article, seven new aromatic polyketides were identified from the fermentation broth of Penicillium commune 518, a marine-derived fungus associated with the Gorgonian, Muricella abnormalis.
Abstract: Seven new aromatic polyketides, communols A–G (1–7), were isolated and identified from the fermentation broth of Penicillium commune 518, a marine-derived fungus associated with the Gorgonian, Muricella abnormalis. The new structures of 1–7 were determined by spectroscopic analysis and X-ray single crystal diffraction. Among them, communol D (4) was the first example of a naturally occurring aromatic polyketide with a sulfoxide group from marine fungi. Compounds 1, 6, and 7 all showed moderate antimicrobial activities against Escherichia coli and Enterobacter aerogenes with MIC values of 4.1/16.4, 6.4/25.8, and 23.8/23.8 µmol·L−1, respectively.

37 citations


Journal ArticleDOI
Jian Zhu1, Ming He1, Feng Qiu1
TL;DR: In this paper, the Young's modulus of graphene with various rectangular and circular vacancy defects is investigated by molecular dynamics simulation, and the fracture behavior of graphene, including the fracture strength, crack initiation and propagation are then studied by the molecular dynamics simulations, the effective spring model, and quantized fracture mechanics.
Abstract: The Young's modulus of graphene with various rectangular and circular vacancy defects is investigated by molecular dynamics simulation. By comparing with the results calculated from an effective spring model, it is demonstrated that the Young's modulus of graphene is largely correlated to the size of vacancy defects perpendicular to the stretching direction. And a linear reduction of Young's modulus with the increasing concentration of mono-atomic-vacancy defects (i.e., the slope of −0.03) is also observed. The fracture behavior of graphene, including the fracture strength, crack initiation and propagation are then studied by the molecular dynamics simulation, the effective spring model, and the quantized fracture mechanics. The blunting effect of vacancy edges is demonstrated, and the characterized crack tip radius of 4.44 A is observed.

34 citations


Journal ArticleDOI
TL;DR: Nized MCM-41-SO3H based on ordered mesoporous silica material with a covalent sulfonic acid group was synthesized and used as acid catalyst for the new, simple, convenient and green synthesis of 2,4,5-trisubstituted and 1,2,4-5-tetra-substitized imidazoles as mentioned in this paper.
Abstract: Nanosized MCM-41-SO3H based on ordered mesoporous silica material with a covalent sulfonic acid group was synthesized and used as acid catalyst for the new, simple, convenient and green synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetra-substituted imidazoles. Also some of synthesis products are new. Echo-friendly protocol, short reaction times, easy and quick isolation of the products and excellent yields are the main advantages of this procedure.

34 citations



Journal ArticleDOI
TL;DR: A series of novel N-pyridylpyrazole carbonyl thioureas were designed and synthesized in this article and their structures were characterized by melting points, 1H NMR, IR and elemental analysis or HRMS.
Abstract: A series of novel N-pyridylpyrazole carbonyl thioureas were designed and synthesized. Their structures were characterized by melting points, 1H NMR, IR and elemental analysis or HRMS. The bioassay tests indicated that some of these compounds exhibited moderate insecticidal activity against Mythimna separata Walker and Culex pipiens pallens. Among 17 compounds, 5n and 5p showed 100% larvicidal activity against Mythimna separata Walker at the test concentration of 100 mg/L.

Journal ArticleDOI
Jiang-Miao Hu1, Wei-Wei Fan1, Fa-Wu Dong1, Ze-Hong Miao1, Jun Zhou1 
TL;DR: In this article, two new phenanthrenes, named chrysotoxols A and B (1, 2) and 24 known compounds were isolated from the stems of the accession species in 2010 Chinese Pharmacopoeia of "Shihu", Dendrobium chrysOToxum.
Abstract: Two new phenanthrenes, named chrysotoxols A and B (1, 2) and 24 known compounds were isolated from the stems of the accession species in 2010 Chinese Pharmacopoeia of "Shihu", Dendrobium chrysotoxum. All structures were elucidated by spectroscopic (NMR, MS, UV and IR) methods and the comparison with reported data in the literatures. Compound 2 and six known phenols were assessed for cytotoxic activity against two human tumor cell lines (A549 and HL-60). The results indicated that erianin may have cytotoxic activity and the other six compounds lost activity at the concentration down to 10-5 mol center dot L-1.

Journal ArticleDOI
Shifeng Li1, Huimin Sun1, Dong Wang1, Li Qian1, Yan Zhu1, Shanjun Tao1 
TL;DR: In this paper, a novel flow injection procedure has been developed for the determination of gallic acid based on the enhancement function for luminol-AgNO3-Ag NPs chemiluminescence (CL) system by gallic acids.
Abstract: A novel flow injection procedure has been developed for the determination of gallic acid based on the enhancement function for luminol-AgNO3-Ag NPs chemiluminescence (CL) system by gallic acid. The enhancement mechanism was proposed for the reinforcing effect of the gallic acid on the CL system. The UV-vis absorption spectrum and CL emission spectrum were applied to confirm the mechanism. The method is simple, rapid and sensitive with a detection limit of 5×10−10 g·mL−1 and a linear range of 8.0×10−10–1.0×10−7 g·mL−1. The relative standard deviation (RSD) is 1.3% for eleven measurements of 5×10−8 g·mL−1 gallic acid. The method has been successfully applied to the determination of gallic acid in Chinese proprietary medicine–Jianmin Yanhou tablets and synthesized samples.

Journal ArticleDOI
TL;DR: In this paper, a relay race mechanism was proposed for N-alkylation reactions of amines/amides with alcohols in the presence of ligand-free homogeneous palladium catalysts.
Abstract: Possibly because homogeneous palladium catalysts are not typical borrowing hydrogen catalysts and ligands are thus ineffective in catalyst activation under conventional anaerobic conditions, they had not been used in the N-alkylation reactions of amines/amides with alcohols in the past. By employing the aerobic relay race methodology with Pd-catalyzed aerobic alcohol oxidation being a more effective protocol for alcohol activation, ligand-free homogeneous palladiums are successfully used as active catalysts in the dehydrative N-alkylation reactions, giving high yields and selectivities of the alkylated amides and amines. Mechanistic studies implied that the reaction most probably proceeds via the novel relay race mechanism we recently discovered and proposed.

Journal ArticleDOI
TL;DR: A series of novel bispyrazoles joined by arylmethylene at C-4 position were synthesized with aromatic aldehydes obtained from lignin and screened for their in vitro antioxidant activities by N,N-diphenyl-N′-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylenzothiazoline-sulphonic acid) diammonium salt (ABTS+) radical scavenging assays.
Abstract: A series of novel bispyrazoles joined by arylmethylene at C-4 position were synthesized with aromatic aldehydes obtained from lignin and screened for their in vitro antioxidant activities by N,N-diphenyl-N′-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylenzothiazoline-sulphonic acid) diammonium salt (ABTS+) radical scavenging assays. All of these compounds exhibited good DPPH and ABST+ radical scavenging activities as compared to the standard, Trolox, which suggested their potential as promising agents for curing tumors or other free radical-related diseases.

Journal ArticleDOI
TL;DR: In this paper, the annulation of allenoates and two molecules of trifluoromethylketone was found under the condition of N-heterocyclic carbene catalysis.
Abstract: In contrast with the reported phosphine- and DABCO-catalyzed [3+2] and [2+2] annulation of allenoates with trifluoromethylketone, the [2+2+2] annulation of allenoates and two molecules of trifluoromethylketone was found under the condition of N-heterocyclic carbene catalysis.

Journal ArticleDOI
TL;DR: In this article, a multicomponent reaction for the synthesis of fused azo-linked pyrazolo[4,3-e]pyridines from 3-amino-5-methylpyrazole, indan-1, 3-dione and synthesized azo linked aldehydes using nano-Fe3O4 as an effective and reusable catalyst is reported.
Abstract: A multicomponent reaction for the synthesis of fused azo-linked pyrazolo[4,3-e]pyridines from 3-amino-5-methylpyrazole, indan-1,3-dione and synthesized azo-linked aldehydes using nano-Fe3O4 as an effective and reusable catalyst is reported. The present methodology offers several advantages, such as a simple procedure with an easy work-up, short reaction times, high yields, and the absence of any volatile and hazardous organic solvents.

Journal ArticleDOI
TL;DR: In this article, a nanosilver-aptamer (AgssDNA) SERS probe was used for the determination of melamine in milk, and the increased SERS intensity ΔI240 cm−1 is linear to melamine concentration in the range of 6.3-403.6 μg·L−1, with a detection limit of 1.2 μg·l−1.
Abstract: The small nanosilver was prepared by the sodium borohydride procedure. The aptamer was used to modify nanosilver to obtain a nanosilver-aptamer (AgssDNA) SERS probe for the determination of melamine. In pH 6.6 phosphate buffer solution and in the presence of NaCl, the AgssDNA probe specifically combined with melamine to release nanosilver particles that were aggregated to nanosilver clusters, which exhibited SERS effect at 240 cm−1. When melamine concentration increased, the nanosilver clusters increased, and the SERS intensity at 240 cm−1 increased. The increased SERS intensity ΔI240 cm−1 is linear to melamine concentration in the range of 6.3–403.6 μg·L−1, with a detection limit of 1.2 μg·L−1. This assay was applied to determination of melamine in milk, with satisfactory results.

Journal ArticleDOI
Yu Zhao1, Yongqiang Li1, Lixia Xiong1, Hongxue Wang1, Zheng-Ming Li1 
TL;DR: Two series of novel anthranilic diamide insecticide containing trifluoroethyl ether were designed and synthesized, and their structures were characterized by 1H NMR spectroscopy, elemental analysis and single crystal X-ray diffraction analysis as discussed by the authors.
Abstract: Two series of novel anthranilic diamide insecticide containing trifluoroethyl ether were designed and synthesized, and their structures were characterized by 1H NMR spectroscopy, elemental analysis and single crystal X-ray diffraction analysis. The insecticidal activities of the new compounds were evaluated. The results of bioassays indicated that some of these title compounds exhibited excellent insecticidal activities. The insecticidal activities of compounds 19a, 19b, 19d, 19g, 19k and 19m against oriental armyworm at 2.5 mg·kg−1 were 100%. The larvicidal activities of 19a, 19b, 19c, 19d, 19e, 19g and 19n against diamond-back moth were 100% at 0.1 mg·kg−1. Surprisingly, most of them still exhibited perfect insecticidal activity against diamond-back moth when the concentration was reduced to 0.05 mg·kg−1, which was higher than the commercialized Chlorantraniliprole.

Journal ArticleDOI
Dongzhi Li1, Xin Wang1, Yutao Jia1, Aiqing Wang1, Yonggang Wu1 
TL;DR: In this paper, a series of soluble hyperbranched polytriazoles, whose number-average molecular weight (Mn) and polydispersity index ranged in (1.2-3)×104 and 1.7-3.0, respectively, were synthesized with A2+B3 approach.
Abstract: It has been a challenge to synthesize high molecular weight and soluble conjugated hyperbranched poly(1,2,3-triazole)s (hb-PTAs). In this paper a series of soluble hyperbranched polytriazoles, whose number-average molecular weight (Mn) and polydispersity index ranged in (1.2–3.3)×104 and 1.7–3.0, respectively, were synthesized with A2+B3 approach. In the polymerization process, diazides A1–A4 and triyne B1 were used as A2 and B3 monomers; Cu(I)-catalyst, THF and water were used as their reaction system. At room temperature the final molecular weight could be controlled through reaction time, so finally we obtained soluble conjugated hyperbranched poly(1,2,3-triazole)s hb-PTAs (1–4). The polymers were soluble in common organic solvents, and all emitted blue light; the films of polymers emitted yellow and blue light, due to the difference in the aggregation of their chromophoric units in the solid state. The thermal properties of the final copolymers were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).

Journal ArticleDOI
TL;DR: The self-assembly of the precatalyst modules, which are amino acids and cinchona alkaloid derivatives, leads to the direct formation of the desired organocatalysts without any synthesis.
Abstract: The self-assembly of the precatalyst modules, which are amino acids and cinchona alkaloid derivatives, leads to the direct formation of the desired organocatalysts without any synthesis. These modularly designed organocatalysts (MDOs) may be used for catalyzed asymmetric aldol reaction. Depending on structure of the aldehyde substrates, the corresponding aldol products may be obtained in mediocre to excellent ee values (up to 92% ee) with moderate diastereoselectivities (up to 79:21 dr).

Journal ArticleDOI
T.Y. Yan1, Shu-Jing Yu1, Pengfei Liu1, Zhuo Liu1, Bao-Lei Wang1, Lixia Xiong1, Zheng-Ming Li1 
TL;DR: In this paper, 8 benzoyl hydrazines containing pyrazole were designed and synthesized for the purpose of finding environmentally benign compounds with high biological activity, low toxicity and low resistance.
Abstract: In search of environmentally benign compounds with high biological activity, low toxicity and low resistance, 8 novel benzoyl hydrazines containing pyrazole were designed and synthesized. All compounds were characterized by 1H NMR spectra and HRMS. The preliminary results of biological activity assessment indicated that most of title compounds exhibited certain insecticidal activities against Mythimna separata Walker at 200 mg·L−1 but excellent fungicidal activities against six fungus at 50 mg·L−1, which were better than the control.

Journal ArticleDOI
Xiaoqing Liu1, Hu Zhou1, Ying Zhang1, Yuanjun Liu1, Aihua Yuan1 
TL;DR: In this article, composites of the Cr3+-based metal-organic framework (MIL-101) and graphene oxide (GO) have been synthesized with different ratios of MIL-101 and GO.
Abstract: Composites of the Cr3+-based metal-organic framework (MIL-101) and graphene oxide (GO) have been synthesized with different ratios of MIL-101 and GO. The composites and the parent material MIL-101 were characterized by X-ray diffraction, scanning electron microscopy and nitrogen adsorption. The results indicated that the incorporation of large amounts of GO (10 and 20 wt%) almost did not prevent the formation of MIL-101 units, but had an obvious impact on the size of MIL-101 crystals. On the contrary, small amounts of GO added (2 and 5 wt%) prevented significantly the proper assembly of MIL-101 units, thus resulting in a pronounced decrease in the porosities of composites.

Journal ArticleDOI
TL;DR: Chiral N-triflyl phosphoramide was found an efficient catalyst for the enantioselective Friedel-Crafts alkylation reaction of 4,7-dihydroindole with β,γ-unsaturated α-keto esters as discussed by the authors.
Abstract: Chiral N-triflyl phosphoramide was found an efficient catalyst for the enantioselective Friedel-Crafts alkylation reaction of 4,7-dihydroindole with β,γ-unsaturated α-keto esters. In the presence of 5 mol% of the optimized catalyst, various pyrrolo[1,2-a]indoles were obtained in excellent enantioselectivity, moderate yields and up to 3:1 diastereoselectivity based on the one-pot synthesis including the Friedel-Crafts alkylation reaction and the subsequent p-benzoquinone oxidation.

Journal ArticleDOI
TL;DR: The combination of isatin, barbituric acid, and cyclohexane-1,3-dione derivatives in the presence of alum (KAl(SO4)2·12H2O) as a catalyst for 15 min was found to be a suitable and efficient method for the synthesis of spiro[chromeno[2,3d]pyrimidine-5,3′-indoline]-tetraones as discussed by the authors.
Abstract: The combination of isatin, barbituric acid, and cyclohexane-1,3-dione derivatives in the presence of alum (KAl(SO4)2·12H2O) as a catalyst for 15 min was found to be a suitable and efficient method for the synthesis of spiro[chromeno[2,3-d]pyrimidine-5,3′-indoline]-tetraones.

Journal ArticleDOI
Haishen Kong1, Weimin Huang1, Haibo Lin1, Haiyan Lu1, Wenli Zhang1 
TL;DR: In this article, a Ti/SnO2-Sb2O5/PbO2 electrode was prepared by electrodeposition method onto Ti substrate with SnO2Sb 2O5 interlayer.
Abstract: The Ti/SnO2-Sb2O5/PbO2 electrode was prepared by electrodeposition method onto Ti substrate with SnO2-Sb2O5 interlayer. Microstructure information of SnO2-Sb2O5 interlayer and PbO2 coating was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Our study shows that the titanium substrate is completely covered by the SnO2-Sb2O5 solid solution interlayer and the interlayer combines the Ti substrate closely with the PbO2 coating. The electrochemical performance of the Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltammogram (CV), electrochemical impedance spectroscopy (EIS) and accelerated life test. The results show the electrochemical activity, electrical conductivity and stability of Ti-substrate lead dioxide electrode are increased. The deactivation process of the Ti/SnO2-Sb2O5/PbO2 electrode was also studied by the EIS. The SnO2-Sb2O5 interlayer can effectively prevent the growth of a TiO2 insulating layer between the substrate and the PbO2 coating during the lifetime tests, thus maintain high activity of Ti/SnO2-Sb2O5/PbO2 electrode for 10 times longer than Ti/PbO2 electrode without interlayer.

Journal ArticleDOI
Lin Gu1, Yusheng Qin1, Yonggang Gao1, Xianhong Wang1, Fosong Wang1 
TL;DR: In this paper, a one-pot terpolymerization of CO2, propylene oxide (PO), and L-lactide (L-LA) in short polymerization time (10 h or shorter) to afford poly(propylene carbonate-Lactide) with excellent mechanical property and thermal stability using Y(CCl3COO)3-ZnEt2-glycerin rare-earth ternary catalyst is reported.
Abstract: A convenient one-pot terpolymerization of CO2, propylene oxide (PO), and L-lactide (L-LA) in short polymerization time (10 h or shorter) to afford poly(propylene carbonate-lactide) with excellent mechanical property and thermal stability using Y(CCl3COO)3-ZnEt2-glycerin rare-earth ternary catalyst is reported. The yield of the copolymerization was between 69.7 and 111.7 g/(g Zn), corresponding to L-LA/PO molar feed ratio varying from 0 to 0.1, and the number average molecular weight was between 5.5x104 and 11.9x104. The L-LA content in the terpolymer increased from 1.1% to 34.7% when L-LA/PO molar feed ratio changed from 0.01 to 0.1. Introducing L-LA as the third comonomer could significantly improve the mechanical strength and thermal stability of PPC. For the terpolymer obtained from L-LA/PO molar feed ratio of 1:50, the elongation at break reached 40.5%, which is 3 times of that of pure PPC, and the thermal decomposition temperature increased by 32 degrees C compared with pure PPC.

Journal ArticleDOI
TL;DR: In this article, an mpg-C3N4-catalyzed oxidation of α-hydroxy ketones to synthesize 1,2-diketones using visible light was reported.
Abstract: As a photocatalyst, mesoporous carbon nitride (mpg-C3N4) shows higher photocatalytic activities in organic synthesis. Herein we report an mpg-C3N4-catalyzed oxidation of α-hydroxy ketones to synthesize 1,2-diketones using visible light. This transformation represents a green and highly efficient synthetic route to synthesize 1,2-diketones for which catalytic approaches are scarce.

Journal ArticleDOI
TL;DR: In this paper, the authors proposed a method to solve the problem of artificial neural networks in the context of artificial intelligence. National Natural Science Foundation of China [20925208, 21103142], National Basic Research Program of China (973 Program) [2012CB821600]
Abstract: National Natural Science Foundation of China [20925208, 21103142]; National Basic Research Program of China (973 Program) [2012CB821600]