CATALYSIS LETTERS
·
2018
·Vol. 148
·期 9
·2636-2642
·
IF 2.911
Yu Zongjiang,Zhai Guoqing,Xian Mo,Lu Ming,Wang Pengcheng,Jiang Tao,Xu Chao,Sun Weizhi
The cleavage of C–N single bonds of N -containing compounds provides either an excellent nitrogen source or an excellent carbon source. In this study, an efficient metalloporphyrins/H 2 O 2 cleavage of C–N bonds of arylpyrazoles was investigated. The effects of different factors, including different catalysts, catalyst dosages, H 2 O 2 dosages, reaction temperature and reaction time were studied. The experimental results showed that the optimal catalyst was FeTPPCl, and the yield of pyrazole derivatives could reach up to 12.3%, which was fourfold higher than hemin catalyzed reaction and closed to ceric ammonium nitrate catalyzed reaction, respectively. Compared with transition-metal-catalyzed and strong-oxidization cleavage of C–N bonds, this protocol is characterized by environmentally-friendly, stable, mild reaction conditions and simplified operation procedures. Graphical Abstract
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Yongmei Xia,Zuming He,Kejun Hu,Bin Tang,Jiangbin Su,Ya Liu,Xiaoping Li
In order to further improve the photocatalytic activity, Cu 2 O coupled with SrTiO 3 was for the first time constructed by introducing SrTiO 3 to Cu 2 O and synthesized via a two-step route. The obtained n-SrTiO 3 /p-Cu 2 O heterojunction photocatalysts were systematically characterized by XRD , XPS , SEM, UV–vis spectra, etc., showing that n-SrTiO 3 /p-Cu 2 O composites were formed by coupling SrTiO 3 submicroparticles with Cu 2 O cubic micrometer structure. Photocatalytic results demonstrated that the introduction of SrTiO 3 brought about significant enhancement of photocatalytic activity of Cu 2 O, which led to the fact that SrTiO 3 could serve as cocatalyst for the degradation of pollutant MB by forming p-n heterojunction to accelerate photo-generated charge carriers separation and migration and providing enriched active sites. The obtained n-SrTiO 3 /p-Cu 2 O heterojunction composites showed good stability and recyclability in the process of photo-degradation. Besides, the possible photocatalytic mechanism was proposed.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2018
·
IF 3.235
Xiaoxia Ye,Xiaofeng Yang,Piaopiao Wei,Kangbing Wu
10-Hydroxycamptothecine (10-HCPT), a natural alkaloid, is widely used in clinical practice because of its significant anti-cancer activity and small toxic side effects. In this work, graphene nanosheets (GNs) were prepared by ultrasonic exfoliation of graphite using N -methylpyrrolidone (NMP) as the solvent. The prepared GNs were characterized using transmission electron microscopy and scanning electron microscopy, and then used to construct a novel sensing platform for 10-HCPT. The electrochemical behaviors of 10-HCPT on the glassy carbon electrode (GCE) and GNs modified GCE (GNs/GCE) were studied. Compared with bare GCE, the prepared GNs/GCE increased the oxidation signal of 10-HCPT significantly, owing to larger active area of GNs/GCE and thus higher accumulation efficiency of 10-HCPT. Utilizing the signal amplification strategy of GNs, a highly-sensitive electrochemical method was established for the detection of 10-HCPT. The linear range was from 10.0 to 250.0 μg L −1 , and the detection limit was 3.21 μg L −1 (8.81 nM). It was used to detect 10-HCPT in urine samples, and satisfactory results were obtained.
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 10
·期 5
·656-662
·
IF 4.927
Qi-Song Tong,Wei Xu,Qiu-Yue Huang,Ya-Ru Zhang,Xiao-Xiao Shi,Hua Huang,Hong-Jun Li,Jin-Zhi Du,Jun Wang
A novel type of multi-stimuli responsive dendrimer with thermo-, pH-, and CO2-responsiveness was developed through facile modification of polyamidoamine dendrimers (PAMAM) with various N-dialkylaminoethyl carbamate moieties. A series of modified PAMAM dendrimers with a well controlled structure were obtained and characterized by 1H NMR. The aqueous solutions of these dendrimers showed a lower critical solution temperature (LCST)-type thermoresponse, and their cloud point temperature (Tcp) was determined by turbidity measurements. Tcp was tunable from 8 to 70 °C, depending on the hydrophobicity and substitution number of the terminal N-dialkylaminoethyl groups, PAMAM generation, pH values, and salt concentrations. Additionally, the solubility of the resultant dendrimers could be reversibly modulated by alternately bubbling CO2 and argon. Our study offers a simple but effective approach to making new multi-stimuli responsive dendrimers for potential smart material applications.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2018
·
IF 2.631
Xiaojiang Liang,Shilin Ye,Qinglong Xie,Meizhen Lu,Fan Xia,Yong Nie,Zhiyan Pan,Jianbing Ji
The solubilities of sulfuryl fluoride (SO 2 F 2 ) in propylene carbonate (PC), tributyl phosphate (TBP) and N-methylpyrrolidone (NMP) was measured by isochoric saturation method at the pressure of up to 600 kPa and temperatures ranging from (293.15 to 313.15) K. Results showed that SO 2 F 2 solubility increased with increasing pressure and decreased with increasing temperature in the three solvents, and the dissolution of SO 2 F 2 in the solvents was a physical process. Moreover, Henry’s law constants and thermodynamic properties such as standard Gibbs free energy, enthalpy, and entropy changes of SO 2 F 2 solvation were further calculated according to the experimental solubility data. The solubility of SO 2 F 2 in these three solvents followed the order of TBP > PC > NMP. The results illustrated that TBP possessed the potentiality to capture SO 2 F 2 among the present absorbents due to the relatively large solubility and low absorption enthalpy for SO 2 F 2 .
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 17
·12374-12387
·
IF 2.993
Ye Zhengqing,Wang Feijun,Jia Chao,Shao Ziqiang
Three-dimensional (3D) O, N-codoped activated carbon aerogels with ultramicropores were prepared via oxidation polymerization, freeze-drying, and carbonization/activation of aniline and sodium alginate. All the O, N-codoped activated carbon aerogels exhibit 3D interconnected hierarchical porous network structures with high specific surface areas (1337–1695 m 2 g −1 ), ultramicropores (0.52–0.54 nm), and rich O (12.68–18.48%) and N (1.18–3.59%) doping. A typical 3D O, N-codoped activated carbon aerogel (ACA700) obtained at the activation of 700 °C exhibits excellent electrochemical performance. When ACA700 is utilized as electrode materials for supercapacitor, the highest specific capacitance of 342 F g −1 at a current density of 2 A g −1 in 3 M H 2 SO 4 electrolyte is achieved. Furthermore, ACA700//ACA700 all-solid-state supercapacitor device displays acceptable energy density (3.8 Wh kg −1 ) at a power density of 246.0 W kg −1 , extraordinary coulombic efficiency (95.8%), and good rate capability. Therefore, the sustainable 3D O, N-codoped activated carbon aerogels with ultramicropores demonstrate tremendous potential for energy storage devices.
✓ 已验证
产品关联
DOI
高影响因子
Royal Society Open Science
·
2018
·Vol. 5
·期 8
·
IF 2.504
Yuting Yan,Yanwei Cao,Chunsheng Xiao,Yang Li,Xiaoxuan Xiang,Xinhua Guo
Herein, the DNA strands containing 5′-(CGA)n and consecutive guanines are used to construct supramolecular DNA nanostructures that are size-controlled by pH values. Additionally, the introduction of thymine linkers within DNA nanostructures is necessary to maintain the stability of long-sized nanostructures. This work also demonstrates a method for accurately building DNA nanostructures.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2018
·
IF 2.179
Qi Tang,You Zhou,Li Ma,Mengyu Gan
The N-doped porous carbon/NiCo 2 O 4 (NPC/NiCo 2 O 4 ) substance is designed and synthesized via hydrothermal treatment , polymerization, carbonization , activation, and chemical bath deposition. The as-prepared NPC/NiCo 2 O 4 holds hemispherical flower-like structure that consists of two things: a porous bowl-shaped NPC at the inside, and sheet NiCo 2 O 4 at the whole outside, in which NPC works as a scaffold for NiCo 2 O 4 to restrain NiCo 2 O 4 nanosheets from aggregation in the synthesis process and NiCo 2 O 4 acts as a capacitive coating layer, and causing a synergic effect. The composite electrode has a specific capacitance of 948.30 F g −1 at a current density of 1 A g −1 , enhanced rate capability (727.43 F g −1 at 16 A g −1 ) and good conductivity. Additionally, NPC/NiCo 2 O 4 reaches a desirable cycling stability (87.4% capacitance retention after 2000 cycles even at a high current density of 10 A g −1 ), suggesting a hopeful electrode material for the electrochemical supercapacitors .
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Dingrui Zhang,Lingyun Hou,Mingyu Gao,Xiaoxiong Zhang
A comprehensive understanding of the thermal cracking behavior of hydrocarbon fuels is important for thermal protection applications and investigations into the combustion of thermally cracked fuels. In the present study, n-dodecane is selected as a surrogate for aviation kerosene and it is subjected to a series of thermal cracking experiments at supercritical pressure. According to variations in chemical heat sink, fuel-conversion rate, and gas-production rate, the thermal cracking of n-dodecane is divided into three regions: primary, secondary, and severe. In the primary cracking region, the fuel-conversion rate is lower than 13%, and the liquid products contain only chain alkanes and alkenes. Owing to the mass fraction of main products being proportional to the fuel-conversion rate, a one-step global reaction kinetics is constructed. The secondary cracking region is characterized by rapidly increasing chemical heat sink, fuel-conversion rates, and gas-production rates with increasing fuel temperature, and the appearance of monocyclic aromatic hydrocarbons (MAHs) and cycloalkenes. A kinetic model containing three reactions is proposed for this region. This also considers the thermal decomposition of chain alkanes and alkenes, which result in the formation of MAHs and cycloalkenes. Severe cracking is observed for fuel-conversion rates above 71% where a rapid increase in the concentration of monocyclic and polycyclic aromatic hydrocarbons (PAHs) occurs. The increasing rate of chemical heat sink slows in this region which is characterized by the formation of MAHs, PAHs, and coke. A three-dimensional numerical model is built for the primary and secondary cracking regions, taking the effects of the flow, heat transfer, and thermal cracking of n-dodecane into consideration. Predicted values for the outlet temperature, fuel-conversion rate, and distribution of the main species in all tested cases agree well with the experimental results, validating the numerical model and kinetics for the primary and secondary thermal cracking of n-dodecane.
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 8
·085020
·
IF 1.449
Hexi Zhao,Yan Wu,Hui Nan,Yonglong Du,Guijun Yang,Gang Wang,Huiyuan Chen,Haomin Wei,Hong Lin
TiO2-ZnO, TiO2-Fe2O3, TiO2-NiO binary heterojunction nanocomposites were synthesized by hydrothermal method using tetrabutyl titanate (TBT) as titanium source. Phase composition, microscopic shape ,functional group characteristics and optoelectronic properties of samples were characterized by x-ray diffractometry (XRD), transmission electron microscopy (TEM), photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), cyclic voltammetry(CV),electrochemical impedance spectra(EIS) and Tafel polarization curve(Taf). The photocatalytic properties of TiO2, TiO2-ZnO, TiO2-Fe2O3 and TiO2-NiO were analyzed by the ability of degradation of methyl orange under visible light irradiation. The experimental results show that the binary heterojunction nanocomposites have been successfully constructed to promote the separation of photogenerated electron-hole pairs and improve the photoelectric performance. The photocatalytic results show that TiO2-NiO exhibits the best photocatalytic performance due to the difference in light utilization efficiency and charge transfer characteristics, which is consistent with the charge transfer resistance of TiO2 > TiO2-ZnO > TiO2-Fe2O3 > TiO2-NiO in EIS results. At the same time, the degradation kinetics of methyl orange (MO) in TiO2-NiO binary heterojunction nanocomposites under visible light irradiation is faster than other samples that can be completed in 160 min. The results show that TiO2-NiO binary heterojunction nanocomposites have broad application prospects in water treatment and wastewater treatment.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2019
·
IF 4.63
Yihu Dai,Chunyang Jiang,Min Xu,Bo Bian,Di Lu,Yanhui Yang
Anilines as important intermediates for both organic synthesis and industrial manufactory are densely substituted with a variety of functional moieties, and the transformation of nitroarenes into corresponding anilines requires catalytically selective hydrogenation catalyst. Herein, we describe a simple pyrolysis strategy to prepare cobalt catalysts in nitrogen-doped carbon matrix applied in the selective hydrogenation of nitroarenes with molecular hydrogen. The Co/NC catalysts are obtained through thermal treatment of mixed precursors of cobalt phthalocyanine and melamine . The surface-modified Co particles with Co 3 O 4 and CoN x sites are surrounded by N-doped carbon layers according to a series of structural characterization results. These Co/NC catalysts are capable of efficiently selective hydrogenation of nitrobenzene and various substituted nitroarenes into corresponding anilines under relatively mild reaction conditions. The optimal catalytic hydrogenation performance is contributed to the fast rate of H 2 dissociated activation on the CoN x active sites and the facile adsorption of the reactant substances, which is verified by the isotopic H 2 -D 2 exchange experiments, reactant adsorption and the ORR reaction tests. Furthermore, the heterogeneous Co/NC catalyst is highly stable without the Co leaching and deactivation issues during the recycling reaction runs.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PORPHYRINS AND PHTHALOCYANINES
·
2018
·
IF 1.217
Xiaoyu Ren,Haizhou Ren,Yunshan Zhou,Lijuan Zhang,Farooq K. Shehzad,Chao Li
New inorganic-organic transparent composite films of the formula (Zn 2 Al-LDH/ZnTPPS) n were fabricated using exfoliated cationic Zn 2 Al layered double hydroxide (Zn 2 Al-LDH) nanosheets and anionic meso -tertra(4-sulfophenyl) zinc porphyrin (ZnTPPS) through an electrostatic layerbylayer self-assembly method. The resulting composite films were characterized by UV-vis spectroscopy (UV-vis) scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results showed that the films have relatively smooth and orderly surfaces, with the large ring plane of the porphyrin molecules vertically aligned LDH nanosheets and can grow in a nearly linear fashion with increasing the deposition cycles. Z-scan measurements, which were conducted under laser irradiation at a wavelength of 532 nm pulse width of 6 ns, repetition rate of 10 Hz and light intensity at focus E of 10 μ J, revealed that the composite films have notable saturation absorption ( cf. , ZnTPPS in solution shows reverse saturation) and optical nonlinear self-defocusing behavior with the nonlinear optical absorption coefficient β refractive index n 2 , and third-order NLO susceptibility χ (3) of the films increasing with the increase in number of layers of films ( χ (3) value is up to 7.86 × 10 -11 esu when n = 40), implying the NLO responses could be modified by fine tuning the thickness of composite films.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）