Chemistry-An Asian Journal
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2020
·Vol. 16
·期 2
·165-173
·
IF 4.056
Ying Duan,Yangyang Ma,Yanfu Xie,Dongmi Li,Dongsheng Deng,Chi Zhang,Yanliang Yang
The reasonable control of the dispersion of noble metals is an important topic for heterogeneous catalysts. In this manuscript, PdCu/C, AuCu/C and PdAuCu/C were prepared by the galvanic reduction method to ensure that Pd and Au follow the distribution of Cu nanoparticles. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive spectrometer elemental mappings and lines scans. Both the Pd and Au had very high dispersion no matter whether they were introduced individually or simultaneously. The Pd and Au were distributed mainly on the Cu nanoparticles as evidenced by the energy-dispersive spectrometer elemental mappings and lines scans. The reduction of 4-nitrophenol was used as a model reaction for the prepared catalysts. PdCu/C and AuCu/C showed high activity for this reaction compared to the literature, and the activity could be further increased by the introduction of Pd and Au in an appropriate ratio at the same time. The normalized reaction rate reached 2.005 s −1 mM −1 for the PdAuCu/C-2.0, in which the mole ratio of Pd to Au was 2.0.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 41
·34692-34698
·
IF 3.289
Ling Wang,Qi Sun,Yang Liu,Zhisong Lu
Carbon nanotubes (CNTs) have been employed as supporting materials for the dispersion of gold nanoparticles (AuNPs) to achieve improved catalytic properties. However, the application of CNT–AuNP composites for the evaluation of chlorophenols (CPs) is not reported. Herein, gold nanoparticle/carboxyl functionalized multi-walled carbon nanotube (AuNPs@cMWCNT) nanocomposites were synthesized via an in situ reduction method and further characterized with field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-vis) spectroscopy and X-ray diffraction (XRD). The AuNPs@cMWCNT modified glassy carbon electrode was subsequently prepared as a sensor for the electrochemical detection of 4-chlorophenol (4-CP). The electro-oxidation of 4-CP on the sensor is an adsorption-controlled irreversible process, which undergoes a two-electron and two-proton transfer. Under the optimal conditions, the oxidation peak current was proportional to the 4-CP concentration in the range of 0.3 to 400 μM, with a detection limit of 0.11 μM. The experimental data demonstrate that the sensor has great reproducibility, long-term stability, high specificity and excellent feasibility. The AuNPs@cMWCNT based sensor could be a facile, low-cost and rapid tool for the potential on-line monitoring of 4-CP in practical applications.
研究领域:
分析化学
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环境科学
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纳米材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2025
·
IF 3.1
Tang Qianyun,Huang Linling,Chen Tingting,Xie Feifei,Tan Hongyan,Chen Donghua
In this paper, a molecular imprinted metal-organic framework was prepared by a simple one-pot method using lanthanide terbium ions as the metal source, 2-aminoterephthalic acid as the organic ligand, and 4-nitrophenol as the template molecule at 120 °C. The materials of imprinted and non-imprinted metal-organic framework were characterized and analyzed by Scanning Electron Microscope, X-ray photoelectron spectroscopy, X-ray Diffraction, Brunauer-Emmett-Teller Specific Surface Area Analysis and fluorescence methods, etc., respectively. The fluorescence of the imprinted metal-organic framework was quenched by 4-nitrophenol in water, and there was a linear correlation between the fluorescence quenching efficiency of molecular imprinted metal-organic framework and the logarithm of 4-nitrophenol concentration in the range of 10–500 µmol L − 1 . The limit of detection was 3.3 µmol L − 1 (3σ) and the limit of quantitation was 11.0 µmol L − 1 (10σ). The molecular imprinted metal-organic framework was used for the determination of 4-nitrophenol concentration in water samples with the recoveries of 93.5-102.9% and the relative standard deviations less than 3.63%. The molecular imprinted metal-organic framework has the advantages of easy preparation, high stability, good sensitivity and selectivity, which has potential application for the detection of 4-nitrophenol in the environment samples. Graphical abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Science
·
2022
·Vol. 9
·期 20
·2201241
·
IF 17.521
Yubo Cui,Mengyang Wang,Peizhe Dong,Shuangshuang Zhang,Junjie Fu,Libo Fan,Chaoliang Zhao,Sixin Wu,Zhi Zheng
A main concern of the promising DMF-based Cu 2 ZnSn(S x ,Se 1- x ) 4 (CZTSSe) solar cells lies in the absence of a large-grain spanning structure, which is a key factor for high open-circuit voltage ( V oc ) and power conversion efficiency (PCE). A new strategy to achieve CZTSSe large-grain spanning monolayer is proposed, by taking advantage of the synergistic optimization with a Cu 2+ plus Sn 2+ redox system and pre-annealing temperatures. A series of structural, morphological, electrical, and photoelectric characterizations are employed to study the effects of the pre-annealing temperatures on absorber qualities, and an optimized temperature of 430 ℃ is determined. The growth mechanism of the large-grain spanning monolayer and the effect of redox reaction rate are carefully investigated. Three types of absorber growth mechanisms and a concept of critical temperature are proposed. The devices based on this large-grain spanning monolayer suppress the recombination of carriers at crystal boundaries and interfaces. The champion device exhibits a high V oc (>500 mV) and PCE of 11.76%, which are both the maximum values among DMF-based solar cells at the current stage.
研究领域:
材料科学
·
太阳能电池研究
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2024
·
IF 5.5
Zhefei Zhao,Xuyao Yao,Linlin Zhang,Minhao Chen,Xingyu Luo,Ruopeng Yu,Yinghua Xu,Youqun Chu,Xinbiao Mao,Huajun Zheng
Electrochemical selective dechlorination for the synthesis of high value-added chemical products is an economical and promising technology. Although silver (Ag) electrode is the most representative catalyst in most electrocatalytic dehalogenation reactions, the selectivity for specific reaction needs to be improved. In this framework, AgCu bimetallic electrocatalysts were designed for the selective dechlorination of 4-amino-3,5,6-trichloropyridine carboxylic acid (4-N-3,5,6-TCP) to 4-amino-3,6-dichloropyridolinic acid (4-N-3,6-DCP). The optimum Ag 16 Cu 4 electrode exhibits excellent performance with 99.0% selectivity and 98.8% yield of 4-N-3,6-DCP, surpassing the pure Ag electrode. The combined results of experimental measurements and theoretical calculations indicated that the introduction of Cu modulates the electronic structure of Ag, which not only promoted the transfer of charges, but also reduces the energy barrier of the rate-determining step (the C H formation). In addition, the practicality and scalability of this system was evaluated using a flow-cell reactor. This study demonstrates that AgCu bimetallic catalyst plays a crucial role in determining the selectivity and activity in the electrochemical dechlorination of 4-N-3,5,6-TCP and displays the prospective applications.
研究领域:
环境科学
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材料科学
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电化学工程
✓ 已验证
产品关联
DOI
高影响因子
KOREA-AUSTRALIA RHEOLOGY JOURNAL
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2024
·
IF 2.2
Hong Zonghao,Wu Shilong,Chen Quan
This study places a focus on flow-induced demixing of polyisoprene (PI) and poly(4-tert butyl styrene) (PtBS) polymer blends with high dynamic contrast. The rheological response is governed by the more immobilized PtBS chains. In contrast, the dielectric response at low frequency reflects exclusively the normal mode of PI chains having type-A dipole parallel along the chain backbone. These features enable selective detection of the component dynamics of PtBS or PI chains under either the small amplitude oscillatory shear or the nonlinear steady shear through a combination of rheological and dielectric techniques. We find the Cox–Merz rule fails significantly for the PtBS/PI blends, which is attributed to flow-induced demixing when the shear rate is higher than the relaxation rate of PtBS chains and lower than that of PI chains. The flow-induced demixing is further supported by varying the molecular parameters of PtBS, copolymerizing PtBS with polystyrene, as well as by the rheo-dielectric measurements that show a broadening of the PI relaxation mode distribution. This demixing could be partly driven by the increased conformational entropy of the PI chains after segregation from the surrounding restrictive PtBS chains. Graphical abstract
研究领域:
高分子科学
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材料科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2017
·
IF 4.233
Peng Xu,Xuguang Liang,Nannan Chen,Jingen Tang,Wei Shao,Qinwei Gao,Zhaogang Teng
In the work, we have synthesized silver (Ag) nanoparticles deposited chitosan (CS) microcapsules with magnetic multiple Fe 3 O 4 cores (denoted as Fe 3 O 4 /CS-Ag) as efficient catalysts for the reduction of 4-nitrophenol. The Fe 3 O 4 /CS-Ag catalysts are prepared by coating hydrophobic Fe 3 O 4 nanoparticles with chitosan via a multiple emulsion-chemical crosslinking method and following in situ deposition of Ag nanoparticles onto the surfaces. The morphology and composition of the Fe 3 O 4 /CS-Ag microcapsules are characterized by Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy. Moreover, the catalytic activity of the Fe 3 O 4 /CS-Ag catalyst was investigated, which shows a conversion efficiency as high as 98% within 15 min for the reduction of p-nitrophenol to p-aminophenol. At the same time, the recovered Fe 3 O 4 /CS-Ag catalyst with an external magnet can retain good activity after 10 cycles. These results indicate that the multiple emulsion-chemical crosslinking method is an efficient and simple way for the preparation of magnetic separable chitosan microcapsules, and the fabricated Fe 3 O 4 /CS-Ag is a promising catalytic material with excellent catalytic activity and convenient recovery ability.
研究领域:
材料科学
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催化化学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2014
·Vol. 39
·期 1
·639-649
·
IF 3.159
Ying Wu,Kaiqiang Liu,Xiangli Chen,Yongping Chen,Shaofei Zhang,Junxia Peng,Yu Fang
A calix[4]arene-based dimeric-cholesteryl derivative with naphthalene in the linkers (C2N2C) was designed and synthesized. The gelation behaviors of the compound in 36 liquids were evaluated. It was demonstrated that C2N2C could gel 16 of the liquids tested, which include both polar and apolar liquids. SEM and AFM studies revealed that the morphologies of the gel networks are dependent on the concentrations of C2N2C and the nature of the liquids under study. Importantly, rheological studies revealed that the gel of the compound in benzene possesses sensitive, fast and fully reversible thixotropic property. More importantly, the Tgel of the C2N2C/benzene gel could be at least more than 60 degrees higher than the boiling point of benzene when the gelator concentration is greater than 6% (w/v), a result never reported before. CD measurements revealed the chiral nature of the assemblies of the gel networks. Further investigation by AFM measurements confirmed the right-hand helical structures of the gel networks of C2N2C/benzene gel. As anticipated, hydrogen bonding and π–π stacking are the two main driving forces for the formation of the gels.
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2018
·
IF 2.21
Xiang Gao,Hao Zhao,Yonggang Liu,Zhenpeng Ren,Cuiping Lin,Jianli Tao,Yunpu Zhai
A facile liquid phase reduction method for the preparation of ternary PdNiP-reduced graphene oxide (PdNiP/RGO) nanocomposites is reported. The PdNiP nanoalloys are well dispersed on RGO without obvious aggregation. Relying on the synergistic electronic effect between Pd, Ni, P and RGO, the PdNiP/RGO nanocomposites exhibit superior catalytic activity toward reduction of 4-nitrophenol (4-NP). The 4-NP can be totally reduced to 4-aminophenol (4-AP) by NaBH 4 over PdNiP/RGO catalyst at room temperature very quickly. The maximum reaction rate constant k obtained with PdNiP loading of 20 wt% (20%PdNiP/RGO) was calculated to be 1.41 min −1 , which is 7.8 times higher than the value of unsupported PdNiP.
研究领域:
材料科学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF FOOD BIOCHEMISTRY
·
2021
·Vol. 46
·期 3
·e13686
·
IF 2.72
Wanxiu Cao,Xin Chen,Yaoxian Chin,Jinkai Zheng,Phaik Eem Lim,Changhu Xue,Qingjuan Tang
Natural compounds have tremendous potential to regulate glucose metabolism, but conventional methods for studying their bioactivities are usually labor intensive. Here, hypoglycemic properties in 22 selected food-derived compounds were examined using molecular docking. The results indicated that curcumin is an inhibitor of both α-glucosidase and dipeptidyl-peptidase 4 (DPP-4), which are important for glycemic control. These effects of curcumin were also confirmed by enzymatic determination in vitro. Furthermore, curcumin significantly improved diet-induced hyperglycemia (e.g., fasting plasma glucose levels and glycogen storage in muscle or liver) in mice. This might be attributed to its inhibitory effects on the activities of α-glucosidase and DPP-4 in vivo. Curcumin also upregulated the expression of genes (e.g., glucagon-like peptide 1) related to DPP-4 activity in the small intestine. In conclusion, curcumin is a potential ingredient of functional foods used for diet-induced hyperglycemia management. Practical applications Curcumin has been widely used as a colorant in the food industry. Moreover, a growing number of studies have described its diverse biological functions, such as anti-inflammatory, anti-oxidant, and anti-angiogenic activities. Thus, curcumin is regarded as a potential ingredient in functional foods. Our results highlighted the hyperglycemic effect of curcumin, suggesting that curcumin may be included in food products for hyperglycemic patients.
研究领域:
药理学
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营养学
·
分子生物学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF INORGANIC BIOCHEMISTRY
·
2011
·
IF 3.317
Li-Jun Tang,Xiang Chen,Yu-Na Sun,Jia Ye,Jing Lu,Ying Han,Xing Jiang,Chan-Chan Cheng,Cheng-Cheng He,Pei-Hong Qiu,Xiao-Kun Li
A new series of complexes of a ligand 4′, 7, 8-trihydroxy-isoflavone with transition metal (zinc, copper, manganese, nickel, cobalt) and selenium have been synthesized and characterized with the aid of elemental analysis , IR, electron ionization mass spectrum (EI-MS) and 1 H NMR spectrometric techniques . The compounds were evaluated for their in vitro antibacterial activities and antitumor properties. The metal complexes were found to be more active than the free ligand. Investigation on the interaction between the complexes and calf-thymus DNA (CT DNA) showed that the absorbance of CT DNA increased and the maximum peak (λ max = 260 nm) red-shifted, while the intensity of fluorescence spectra of Epstein-Bart DNA (EB-DNA) gradually weakened, which indicated that all of these metal complexes tightly combined with CT DNA.
研究领域:
生物化学
·
药物化学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yujiao Zou,Chenyu Li,Ni Li,Yili Zhao
Silver nanoparticles (Ag NPs)-based nanomaterials are effective catalysts for a wide range of reactions. The recyclability and efficient catalytic properties of Ag-based nanocatalysts have been the focus of significant research interest. Herein, to address these challenges, we incorporated Fe 3 O 4 nanoparticles (NPs) into a polyvinyl alcohol/polyethyleneimine (PVA/PEI) solution to fabricate PVA/PEI@Fe 3 O 4 nanofibrous mats via electrospinning. Subsequently, the magnetic nanofibrous mats were homogenized to produce short magnetic nanofibers, which can be easily separated from the solution using a magnet. These short PVA/PEI@Fe 3 O 4 nanofibers were then immersed in an aqueous solution of AgNO 3 to adsorb and reduce Ag ions, resulting in the formation of Ag NPs with an average diameter of approximately 15 nm, uniformly dispersed on the nanofiber surface. The resulting short PVA/PEI@Fe 3 O 4 /Ag nanofibers exhibit excellent catalytic activity for the reduction of 4-NP, achieving a high conversion rate of 97.0 %. Furthermore, they demonstrated remarkable recyclability, maintaining high catalytic activity throughout six consecutive cycles. The short magnetic nanofibers proposed in this study are anticipated to facilitate the practical application of electrospun nanofibers in the catalytic removal of pollutants.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）