FUEL
·
2020
·
IF 5.578
Xiao Zhou,Xian-Yong Wei,Yu-Miao Ma,Zhi-Min Zong
An active bifunctional nickel-based catalyst was prepared by decomposing Ni(CO) 4 to dispersive metallic Ni on Hβ zeolite and successfully applied in the catalytic hydroconversion (CHC) of an alkali lignin (AL). Detailed elemental composition, functional groups, and molecular compositions of the soluble portions (SPs) from non-catalytic hydroconversion (SP NCHC ) and CHC (SP CHC ) were characterized with an elemental analyzer, a Fourier transform infrared spectrometer, and a gas chromatograph/mass spectrometer (GC/MS). As a result, alkoxalkanes, phenol, cresol, veratrols, alkyl-substituted 1,4-dimethoxyphenols, 2,5-dimethylfuran, 3-hydroxyneopentanal, 4-methylpent-3-en-2-one, 4-methoxy-4-methylpentan-2-one, 1-(2,4-dihydroxy-3-tolyl)propan-1-one, and 2,5-dimethylhex-4-enoic acid only appear in SP CHC , and yields of multiple alkyl-substituted phenols, p -alkylanisoles, diols, non-substituted and alkyl-substituted methoxyphenols, and substituted phenylethanones in SP CHC are significantly higher than those in SP NCHC . The mechanism for catalytically hydrocracking >CH-O- bridged bonds over Ni/Hβ is proposed using benzyloxybenzene (BOB) and phenethoxybenzene as AL-related model compounds. Ni/Hβ proved to be stable after 3 cycles with relatively small loss in catalytic activity for catalyzing the hydrocracking of >CH-O- bonds in BOB.
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CARBON
·
2021
·
IF 9.594
Mengmeng Yang,Qingquan Kong,Wei Feng,Weitang Yao
In this study, N/O co-doped cage-type biomass carbon (NOBC) was prepared through a simple and facile hydrothermal reaction and two-step carbonization method. As the anode of a potassium ion battery, NOBC displays a superhigh long-cycling performance and a super high rate performance. NOBC-2 provides an excellent reversible capacity of 251.2 mAh g −1 after 1500 cycles at 0.5 A g −1 , and an excellent performance of 334.6 mAh g −1 at a high current density of 5 A g −1 (after 2000 cycles). The reversible capacity of 124.19 mAh g −1 can be maintained even after 5000 cycles at 10 A g −1 . The excellent performance of NOBC is attributed to the unique hollow cage structure, internal 3D carbon network structure and N/O co-doping. Based on the results of detailed fundamental analysis, the pseudo-capacitance mechanism contributes to the higher K ion storage process in NOBC-2. Density functional theory (DFT) calculations further show that N/O double doping can promote the adsorption of K ions in biomass carbon materials and improve the conductivity of the materials. The simple synthesis route and excellent electrochemical performance provide new insights for the search for novel carbon-based K storage anode materials with high energy and long cycle life.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 17
·7417-7431
·
IF 3.553
Meng Xingtong,Jia Shuai,Mo Lanlan,Wei Jie,Wang Feijun,Shao Ziqiang
Nowadays, it has become a trend to prepare porous carbon as electrode materials for supercapacitors by using biomass and its derivatives by virtue of its low cost, abundant source and environmental friendliness. Carboxymethyl cellulose ammonium (CMC-NH 4 ), a kind of cellulose derivative, is used as a carbon precursor and O/N source to prepare carbon material through cross-linking with aluminum ions, lyophilization, carbonization and activation. The as-prepared O/N-co-doped carbon samples (ONAC-500, ONAC-600 and ONAC-700) exhibit hierarchically porous structure with different size pores in carbon framework, ensuring electrolyte ions effective transport and diffusion. Meanwhile, the ONAC-600 reveals a high specific surface area of 2658 m 2 g −1 , abundantly porous structure with pore volume of 1.32 cm 3 g −1 and effective O/N-doping, which ensure a high capacitance of 465.0 F g −1 at 1 A g −1 in 3 M KOH three-electrode system. It also shows better rate capability and good stability after 10000 cycled under 10 A g −1 . Besides, the assembled all-solid-state supercapacitor with ONAC-600 delivers an acceptable energy density of 7.8 Wh kg −1 at a power density of 124.2 W kg −1 .
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高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Benteng Sun,Zhangqian Liang,Yeye Qian,Xuesong Xu,Ye Han,Jian Tian
Here, we reported that sulfur vacancy-rich O-doped 1T-MoS2 nanosheets (denoted as SV-1T-MoS2) can surpass the activity of Pt as cocatalysts to assist in the photocatalytic nitrogen fixation of CdS nanorods. SV-1T-MoS2 cocatalysts exhibit sulfur vacancies, O-doping, more metallic 1T phase, and high electronic conductivity, thus leading to the exposure of more active edge sites, high Brunauer–Emmett–Teller surface area, enhanced visible light absorption, and improved electron separation and transfer, which are beneficial for photocatalytic nitrogen fixation. Consequently, the optimized 30 wt % SV-1T-MoS2-/CdS composites exhibit an outstanding nitrogen fixation rate of 8220.83 μmol L–1 h–1 g–1 and long-term stability under simulated solar light irradiation, significantly higher than pure CdS nanorods, CdS–Pt (0.1 wt %), and 30 wt % 1T-MoS2/CdS composites. The catalytic mechanism of photocatalytic nitrogen fixation on SV-1T-MoS2 is discussed by density functional theory calculations.
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高影响因子
Light-Science & Applications
·
2022
·Vol. 11
·期 1
·1-11
·
IF 20.257
Li Pengfei,Xue Shanshan,Sun Lu,Zong Xupeng,An Li,Qu Dan,Wang Xiayan,Sun Zaicheng
Carbon dots (CDs) as the advancing fluorescent carbon nanomaterial have superior potential and prospective. However, the ambiguous photoluminescence (PL) mechanism and intricate structure-function relationship become the greatest hindrances in the development and applications of CDs. Herein, red emissive CDs were synthesized in high yield from o -phenylenediamine (oPD) and catechol (CAT). The PL mechanism of the CDs is considered as the molecular state fluorophores because 5,14-dihydroquinoxalino[2,3-b] phenazine (DHQP) is separated and exhibits the same PL properties and behavior as the CDs. These include the peak position and shape of the PL emission and PL excitation and the emission dependence on pH and solvent polarity. Both of them display close PL lifetime decays. Based on these, we deduce that DHQP is the fluorophore of the red emissive CDs and the PL mechanism of CDs is similar to DHQP. During the PL emission of CDs, the electron of the molecule state can transfer to CDs. The formation process of DHQP is further confirmed by the reaction intermediates (phthalazine, dimers) and oPD. These findings provide insights into the PL mechanism of this type of CDs and may guide the further development of tunable CDs for tailored properties.
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Chemosensors
·
2022
·Vol. 10
·期 10
·407
·
IF 4.229
Yaqin Chen,Xia Peng,Yonghai Song,Guangran Ma
An electrochemical sensor based on a molecularly imprinted polymer membrane (MIP) was developed. The electrochemical sensor was prepared by electropolymerization of o-phenylenediamine (O-PD) on the surface of glassy carbon electrode (GCE), modified by AuNPs@covalent organic framework (COF) microspheres with ascorbic acid (AA) as template molecule. First, ultrasmall polyvinylpyrrolidone (PVP)-coated AuNPs were prepared by a chemical reduction method. Then, 1,3,5-tri(p-formylphenyl)benzene (TFPB) and N-boc-1,4-phenylene diamine (NBPDA) underwent an ammonaldehyde condensation reaction on PVP-coated AuNPs to form AuNPs@COFTFPB-NBPDAmicrospheres. The porous spherical structure of AuNPs@ COFTFPB-NBPDAcould accelerate the mass transfer, enlarge the specific surface area, and enhance the catalytic activity of PVP-coated AuNPs. The electrochemical sensors, based on AuNPs@ COFTFPB-NBPDA/GCE and nMIPs/AuNPs@COFTFPB-NBPDA/GCE, were applied for the detection of AA, with a detection limit of 1.69 and 2.57 μM, as well as linear ranges of 5.07 to 60 mM and 7.81 to 60 mM. The nMIPs/AuNPs@COFTFPB-NBPDAsensor had satisfactory stability, selectivity, and reproducibility for AA detection.Keywords:covalent organic framework;ascorbic acid;molecularly imprinted polymer;electrochemical sensor
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MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Shangying Qin,Li Huang,Dan Li,Zhongwei Lin,Chuang Wen,Yilin Wang
Fe 7 S 8 nanosheets (Fe 7 S 8 NSs) was prepared from ferrous sulfate and thiourea, showing peroxidase-like activity and enabling the oxidation of o-phenylenediamine (OPD) in the presence of H 2 O 2 to produce 2,3-diaminophenol (DAP) with strong absorption and fluorescence peaks at 450 and 560 nm, respectively. Furthermore, both the level of absorbance at 450 nm ( A 450 ) and the intensity of fluorescence at 560 nm ( F 560 ) depended on the concentration of H 2 O 2 . As a result, a dual response (colorimetry and fluorescence) method for the assay of H 2 O 2 was established. Due to the fact that H 2 O 2 can be produced from glucose oxidase catalyzed glucose oxidation, A 450 and F 560 were further used for indirect determination of glucose. The results indicated that the absorbance and fluorescence responses were closely related to glucose concentration in the range of 1.0–100 μM and 1.0––70 μM with the detection limit of 0.83 and 0.52 μM, respectively. To verify its practicality, the method has been used for determining glucose in human serum samples with recoveries ranging from 92.2 to 106.2 %, suggesting its promising potential applications.
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JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2023
·Vol. 104
·期 2
·797-808
·
IF 4.1
Fuge Niu,Mengdi Zhao,Weiwei Tu,Zhe Li,Yi Gao,Yixuan Du,Weichun Pan
BACKGROUND In order to study the effect of adsorption of surfactant at the two interfacial layers on emulsion stability, the kinetically stable water-in-oil-in-water (W/O/W) emulsion carriers were prepared using polyglycerol polyricinoleate (PGPR) and gum arabic (GA) as emulsifiers. The relationship between the adsorption of the surfactant and the stability mechanism of the emulsions was elucidated. RESULTS When the contents of PGPR and GA were low, the interfaces between oil and the inner and outer water phases, respectively, could not be completely covered. However, when the concentration of PGPR was higher than 60 g kg −1 , the excess PGPR was adsorbed on the interface between the oil phase and the outer water phase. When the concentration of GA reached 80 g kg −1 , more GA was adsorbed to the oil-in-water interface. Moreover, the presence of PGPR on the interface could reduce the adsorption capacity of GA. Two types of kinetically stable emulsions were obtained by optimizing the interface composition (60 g kg −1 GA/80 g kg −1 PGPR and 60 g kg −1 PGPR/80 g kg −1 GA). The kinetically stable W/O/W emulsions prepared in this study were successfully used to encapsulate a hydrophilic vitamin (vitamin B12) with an encapsulation efficiency (EE) of 80% and release efficiency (RE) of 95%. The interfacial adsorption GA can accelerate the hydrolysis of fat. CONCLUSION Overall, this study provides a new strategy for the preparation of W/O/W emulsions, which might be beneficial for application in food, cosmetic, chemical, and pharmaceutical industries. © 2023 Society of Chemical Industry.
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INTERNATIONAL JOURNAL OF PHARMACEUTICS
·
2023
·
IF 5.8
Mingxi Jia,Weidong Bai,Jing Deng,Wen Li,Qinlu Lin,Feifei Zhong,Feijun Luo
Octacosanol , a naturally occurring higher fatty alcohol , possessed numerous biological effects. However, octacosanol limited solubility in water due to its lipophilic nature and large structure, resulting in poor absorption and low bioavailability. To overcome this challenge, we developed a simple, environmentally friendly, and energy-efficient O/W nanoemulsion synthesis process. The nanoemulsion achieved an average droplet size of approximately 30 nm, exhibited excellent dispersibility and stability at room temperature for 60 days, and showcased robust storage properties insensitive to ambient temperature, pH, NaCl, and sucrose. Remarkably, the preparation process of the nanoemulsion maintained the biological activity of octacosanol while demonstrating significantly enhancing antioxidant activity compared to octacosanol suspension. Additionally, the nanoemulsion displayed negligible cytotoxic effects on Caco-2 cells. Significantly, the octacosanol nanoemulsion exhibited a 5.4-fold enhancement in transmembrane transport efficiency when compared to the suspension in Caco-2 cell monolayers. Additionally, in an in vivo experiment, there was a notable 2.9-fold increase in rat intestinal absorption. These findings could provide valuable insights into the development of octacosanol nanoemulsion, supporting its future applications and paving the way for the design of stable nanoemulsion systems for other lipophilic and sparingly soluble substances.
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高影响因子
MOLECULES
·
2023
·Vol. 28
·期 24
·8013
·
IF 4.6
Yuzhou Xia,Xinghe Xia,Shuying Zhu,Ruowen Liang,Guiyang Yan,Feng Chen,Xuxu Wang
Visible-light-driven N2reduction into NH3in pure H2O provides an energy-saving alternative to the Haber–Bosch process for ammonia synthesizing. However, the thermodynamic stability of N≡N and low water solubility of N2remain the key bottlenecks. Here, we propose a solution by developing a WO3−xhollow sphere with oxygen vacancies. Experimental analysis reveals that the hollow sphere structure greatly promotes the enrichment of N2molecules in the inner cavity and facilitates the chemisorption of N2onto WO3−x-HS. The outer layer’s thin shell facilitates the photogenerated charge transfer and the full exposure of O vacancies as active sites. O vacancies exposed on the surface accelerate the activation of N≡N triple bonds. As such, the optimized catalyst shows a NH3generation rate of 140.08 μmol g−1h−1, which is 7.94 times higher than the counterpart WO3-bulk.Keywords:WO3;hollow sphere;O defect;N2reduction;photocatalysis
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LANGMUIR
·
2023
·
IF 3.9
Ruixin Song,Shifei Kang,Liangtao Yao,Lulu Zheng,Dechao Yu,Dawei Zhang
BiVO4 has been widely used in the field of photocatalysis due to its nontoxic and moderate band gap. However, single BiVO4 has the disadvantages of a high recombination rate of photogenerated carriers and weak response to visible light, inhibiting its photocatalytic applications. To explore viable solutions, a hybrid material composed of lanthanum-doped bismuth vanadate (La-BiVO4) and oxygen-doped porous graphite carbon nitride (O-doped g-C3N4), i.e., La-BiVO4/O-doped g-C3N4 powder, was prepared by a facile hydrothermal reaction and low-temperature calcination. Then, the powder was loaded on polyacrylonitrile nanofibers (NFs) through the electrospinning fiber technique. Various surface science characterizations, including transmission electron microscopy and nitrogen absorption and desorption analysis, confirmed the successful synthesis of a mesoporous heterojunction material. The La3+-doping as well as the porous morphologies and larger specific surface area of the O-doped g-C3N4 ultimately improve the photocatalytic abilities via a proposed Z-scheme heterojunction mechanism. The roles of La3+-doping and morphology modification in promoting the separation of the photogenerated carriers and broadening the optical absorption range were experimentally discussed. The RhB degradation experiment indicated that the La-BiVO4/O-doped g-C3N4 powder has excellent photocatalytic activity, which is about 2.85 and 2 times higher than that of the pure BiVO4 and O-doped g-C3N4, respectively. Meanwhile, the La-BiVO4/O-doped g-C3N4 NF shows good stability and recoverability after a 10-cycle testing. Such a hybrid photocatalyst with a proposed Z-scheme heterojunction mechanism and good plasticity might pave a feasible way to fabricate a new library of photocatalysts.
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高影响因子
Foods
·
2023
·Vol. 12
·期 5
·1068
·
IF 5.2
Meixiang Yao,Xin Qi,Jiahui Zhang,Chengyuan Wang,Jianhua Xie
Mesona chinensispolysaccharide (MCP), a common thickener, stabilizer and gelling agent in food and pharmaceuticals, also has antioxidant, immunomodulatory and hypoglycemic properties. Whey protein isolate (WPI)-MCP conjugate was prepared and used as a stabilizer for O/W emulsion in this study. FT-IR and surface hydrophobicity results showed there could exist interactions between -COO- in MCP and -NH3+in WPI, and hydrogen bonding may be involved in the covalent binding process. The red-shifted peaks in the FT-IR spectra suggested the formation of WPI-MCP conjugate, and MCP may be bound to the hydrophobic area of WPI with decreasing surface hydrophobicity. According to chemical bond measurement, hydrophobic interaction, hydrogen bond and disulfide bond played the main role in the formation process of WPI-MCP conjugate. According to morphological analysis, the O/W emulsion formed by WPI-MCP had a larger size than the emulsion formed by WPI. The conjugation of MCP with WPI improved the apparent viscosity and gel structure of emulsions, which was concentration-dependent. The oxidative stability of the WPI-MCP emulsion was higher than that of the WPI emulsion. However, the protection effect of WPI-MCP emulsion on β-carotene still needs to be further improved.Keywords:Mesona chinensispolysaccharide;whey protein isolate;conjugate;emulsion
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危险品化学品经营许可证（带存储）