MATERIALS RESEARCH BULLETIN
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2018
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IF 2.873
Zhuanni Yu,Mengmeng Xu,Qiang Wang,Xiaowei Sun,Jing Lan
An efficient semiconductor composite, silver/silver orthophosphate/silver bromide, was successfully synthesized by a facile one-step reduction and ion exchange process. Its crystal structure, morphology, optical property, surface element composition were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet-visible diffuse reflectance spectrometer and X-ray photoelectron spectrometer. The effects of composite proportion and synthesis duration on performances of as-prepared photocatalysts were investigated, and the results showed that Br/P molar ratio of 3 and the synthesis duration of 4 h were the optimum conditions. The radical scavenging experiments indicated that the hole and superoxide radical were the main active species in this reaction system. The Ag/Ag 3 PO 4 /AgBr-3 presented excellent stability and recyclability, maintaining 92% of degradation efficiency after 5 cycles. The good photocatalysis performance could be attributed to the formation of the heterojunction between Ag and Ag 3 PO 4 /AgBr.
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高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2014
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IF 2.129
Yecang Tang,Ting Wu,Botao Hu,Qian Yang,Li Liu,Bo Yu,Yi Ding,Shiyong Ye
Ag nanoparticles (AgNPs)-containing hybrid microgels were prepared by in situ reduction of Ag + ions pre-dispersed in copolymer microgels of poly ( N -isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate) (P(NIPAM-co- DMA)). The prepared hybrid microgels possess excellent thermo- and pH-responsive properties and exhibit a responsive swelling and shrinking behavior. The increase in pH can induce a decrease in the absorption intensity and a blue shift of the surface plasmon band of AgNPs, which is attributed to a reduction in the polarity of AgNPs surroundings as a result of the conformational change of PDMA segments. Furthermore, the hybrid microgel was found to be an active catalyst for the reduction of methylene blue by NaBH 4 in aqueous solution. The effects of temperature and the amount of catalyst on the reduction rate were investigated using UV–vis spectrophotometry . Kinetic studies indicate that the apparent reaction rate constant k app follows the typical Arrhenius-type dependence on temperature in the range of 25 ∼ 40 °C and the activation energy is 62.0 kJ mol −1 . The AgNPs embedded in hybrid microgels show good thermal and chemical stability and the catalytic activity remains unchanged after storage for 40 days at room temperature. Such hybrid microgels, with the merits of good thermal and chemical stability as well as the catalytic activity, have a potential application in the field of heterogenous catalysis.
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高影响因子
Scientific Reports
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2014
·Vol. 4
·期 1
·1-9
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IF 5.078
Jiang Jizhou,Ou-Yang Lei,Zhu Lihua,Zou Jing,Tang Heqing
Through in-situ reduction of silver nitrate without using any coupling-agent, a substrate for surface-enhanced Raman scattering (SERS) was prepared by coating silver on hollow buoyant silica microspheres as a lab on a bubble (LoB). The silver coated LoBs (LoBs@Ag) floated on surface of a solution could provide a very convenient platform for the detection of target molecules in the solution. The LoBs@Ag substrate not only immobilized well-distributed Ag nanoparticles on the surface LoBs, but excluded the interference of coupling agents. This yielded high-resolution SERS spectra with excellent reproducibility. The adsorption of crystal violet (CV) on the LoBs@Ag substrate was investigated by means of SERS combined with density functional theory (DFT) calculations. The LoBs@Ag substrate exhibited a remarkable Raman enhancement effect for CV with an enhancement factor of 6.9 × 10 8 and wide adaptability from dye, pesticide to bio-molecules. On the basis of this substrate, a simple and sensitive SERS method was proposed for the determination of trace organic pollutants or bio-molecules.
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PubMed
高影响因子
RSC Advances
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2015
·Vol. 5
·期 121
·99914-99919
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IF 3.84
S. N. Chen,X. Li,S. Han,J. H. Liu,Y. Y. Zhao
Ag–molecularly imprinted polymer (MIP) hybrid composites (Ag@MIPs) were prepared for the ultra-sensitive detection of organic pollutants in water based on surface enhanced Raman scattering (SERS). The prepared Ag@MIPs hybrid, with about a 2 nm ultrathin polymer shell, exhibited high affinity. Meanwhile, upon SERS measurements, the limit of detection for the Ag@MIPs hybrid can be as low as 10−12 M for the target molecule Rhodamine B, which was three orders of magnitude higher than classical SERS detection on silver nanoparticles. Furthermore, the Ag@MIPs hybrid also showed good reproducibility and high selectivity toward structurally related analogues. In addition, the present work provides a promising platform for the highly sensitive and selective detection of organic pollutants in water based on SERS measurements.
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高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
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2014
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IF 1.761
Sheng-ying Ye,Sheng-wen Shen,Lu-meng Ye,Xian-liang Song,Shu-can Luo
Silver nanoparticles (AgNPs), obtained by reduction from AgNO 3 solution and stabilized in polyvinyl pyrrolidone (PVP), have been synthesized by γ-ray radiolysis . The application of photoelectrocatalytic (PEC) oxidation in ethylene gas treatment using a TiO 2 photocatalyst combined with as-prepared AgNPs on activated carbon fiber (ACF) ([Ag+TiO 2 ]/ACF) as a photoelectrode in a Nafion-based photoelectrocatalytic cell is presented. The effects on the PEC degradation of C 2 H 4 of the preparation parameters of the AgNPs, such as the radiation dose and the amount of PVP added, have been systematically investigated. Emphasis is placed on comparison of the C 2 H 4 decomposition rate constant with [Ag+TiO 2 /ACF] as a photoelectrode in a photoelectrocatalytic cell with that achieved with [TiO 2 /ACF]. The factors responsible for the enhancing effect of AgNPs on the PEC activity of the [Ag+TiO 2 /ACF] photoelectrode are discussed.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2015
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IF 2.999
Yanqin Yang,Mengmeng Kang,Shaoming Fang,Minghua Wang,Linghao He,Xiaozhong Feng,Jihong Zhao,Zhihong Zhang,Hongzhong Zhang
It is highly desirable and a popular topic in scientific research to develop a highly sensitive and selective detection and quantitative analysis method of determining trace silver ions (Ag + ) in aqueous media since Ag + ions are recognized as one of the most hazardous metal pollutants. Three-dimensional graphene oxide (3D-GO) was decorated with Fe 3 O 4 to form nanocomposites of Fe 3 O 4 @3D-GO, which were further used as electrode materials in an electrochemical DNA sensor for detecting Ag + . Because of the chemical functionality and porous structure of the developed nanocomposites, single-stranded and cytosine-rich oligonucleotides could be anchored onto their surfaces or interior, followed by selective detection of Ag + through formation of C–Ag + –C complex forms. The results of electrochemical measurement showed that the Fe 3 O 4 @3D-GO nanocomposites exhibits high sensitivity for detecting Ag + with a detection limit of 2.0 pM within the range of 0.01–100 nM Ag + (S/N = 3). The developed electrochemical biosensor based on Fe 3 O 4 @3D-GO exhibits highly selectivity, good repeatability, and stability for detecting Ag + ions. The results of this work demonstrate that Fe 3 O 4 @3D-GO nanocomposites could be used as a promising tool to detect heavy metal ions in water or the environment.
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高影响因子
APPLIED SURFACE SCIENCE
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2015
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IF 2.711
Guangliang Chen,Xiaolei Si,Jinsong Yu,Huiyu Bai,Xianhui Zhang
This paper reports the synthesis of nanosized Ag/Co 3 O 4 composite catalysts using a silver-mirror reaction and the calibration of their catalytic activities towards methyl blue (MB) dye degradation with peroxymonosulfate (PMS) under visible light. The nanosized Ag/Co 3 O 4 composites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV–vis spectroscopy. The experimental evidence indicated that the hydrothermal synthesis approach lead to the exposure of the {1 1 2} facets of the Co 3 O 4 nanoflakes. Compared to Co 3 O 4 nanoflakes, Co 3 O 4 doped with Ag nanoparticle (average diameters of 10–15 nm) presented lower band gap energy and photoluminescent (PL) intensity. Meanwhile, the Ag/Co 3 O 4 exhibited high stability and excellent dispersion property in dye solution. Experimental data suggested that 3.06 wt% Ag nanoparticle-doped Ag/Co 3 O 4 nanocomposite catalyst possessed the highest catalytic activity towards MB degradation in aqueous solution at the tested concentration level of 15 mg/L, about 2.4 times higher than that of pure Co 3 O 4 . Complete decolorization of the 15 mg/L MB solution can be achieved by 3.06 wt% Ag-doped Ag/Co 3 O 4 nanocomposite within 20 min of visible light irradiation.
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高影响因子
RSC Advances
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2013
·Vol. 3
·期 38
·17469-17476
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IF 2.562
Li-Jun You,Qiao An,Jia Guo,Jack J. Hu,Chang-Chun Wang
Uniform MF/Ag-NPs core–shell composite microspheres were fabricated as isolated SERS (surface-enhanced Raman scattering)-active substrates through coating of Ag nanoparticles (Ag-NPs) onto MF (melamine formaldehyde resin) microspheres. These composite microspheres can be imaged and individually manipulated under an optical microscope. Their SERS spectra can be taken at the focal point to ensure the best analysis result or to recognize the identity of the microsphere for flow cytometry. In this paper, the SERS activity of the composite microspheres was evaluated using 4-ABT, 4-CBT, and 4-DTNB as the Raman reporting molecules; the SERS data of tetramethylthiuram disulfide were also acquired on the isolated MF/Ag-NPs core–shell composite microsphere. Due to the significant electromagnetic coupling effect created by the Ag-NPs on the MF microsphere, the SERS detection limits for 4-ABT, 4-CBT, and 4-DTNB were as low as 10−9 mol L−1, 10−10 mol L−1, and 10−8 mol L−1, respectively. For the insecticide tetramethylthiuram disulfide, the detection limit was 10−9 mol L−1 using the isolated MF/Ag-NPs microsphere as the SERS substrate. The SERS signal intensity linearly depended upon the concentration of tetramethylthiuram disulfide, indicating that the MF/Ag-NPs core–shell composite microsphere can be used for quantitative analysis of this insecticide.
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高影响因子
RSC Advances
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2015
·Vol. 5
·期 124
·102610-102618
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IF 3.84
Yufeng Shan,Yong Yang,Yanqin Cao,Zhengren Huang
Nanocomposites of noble metal and magnetic materials deliver both SERS activity and magnetic properties, and thereby have great advantages for trace analysis in the fields of analytical chemistry, biological and environmental sciences. In this work, Ag/Fe3O4 nanocomposites have been obtained by a facile one-pot solvothermal method. The Fe3O4 nanoparticles (NPs) compounded with Ag possess excellent superparamagnetism, which guarantees an effective self-aggregation of the Ag/Fe3O4 composites. The saturation magnetic moment and SERS activity of the as-prepared nanocomposites are easily optimized by adjusting the mole ratio of silver oleate and iron oleate. The sample with Ag/Fe = 5 possesses optimal SERS performance for both R6G and MB detection. The Fe3O4 NPs with ultra small size behave just like glue or a contractile net, which wrap the Ag NPs together under an external magnetic field and give rise to high-density and high-intensity “hot-spots”. The enhancement factors (EFs) of the sample with Ag/Fe = 5 are over ∼108 both for R6G and MB detection. The as-prepared magnetic nanocomposites have been applied to realize an efficient but convenient real-time on-line monitoring of atrazine in flowing pesticide contaminated water, which show enormous potential in the application of on-line monitoring for industrial and agricultural production.
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高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2015
·
IF 4.097
Hong Huang,Hua Li,Jiu-Ju Feng,Ai-Jun Wang
Herein, we demonstrate a facile, straightforward and green method for synthesis of highly red-emitting fluorescent bimetallic Au/Ag nanoclusters (NCs) employing lipoic acid as both a reducing agent and a protecting agent. The as-prepared Au/Ag NCs exhibited bright red emission with a strong peak centered at 630 nm (quantum yield measured as 6.4%), and showed excellent stability and remarkable temperature-dependent fluorescent property. The fluorescence responses were reversible and linear to the environment temperature from 20 to 65 °C with a resolution as high as 1.34 °C, which allows its potential application as a fluorescent nanothermometer. Moreover, Au/Ag NCs were also explored for selective and sensitive determination of Fe 3+ based on the specific quenching of the fluorescence by Fe 3+ , and explored for fluorescence imaging Fe 3+ in living HeLa cells thanks to their very low cytotoxicity.
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高影响因子
Nano Research
·
2016
·Vol. 9
·期 3
·876-885
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IF 8.893
Qian Hongmei,Xu Meng,Li Xiaowei,Ji Muwei,Cheng Lei,Shoaib Anwer,Liu Jiajia,Jiang Lan,Zhu Hesun,Zhang Jiatao
This study reports the controllable surface roughening of Au–Ag alloy nanoplates via the galvanic replacement reaction between single-crystalline triangular Ag nanoplates and HAuCl 4 in an aqueous medium. With a combination of experimental evidence and finite element method (FEM) simulations, improved electromagnetic field (E-field) enhancement around the surface-roughened Au–Ag nanoplates and tunable light absorption in the near-infrared (NIR) region (~800–1,400 nm) are achieved by the synergistic effects of the localized surface plasmon resonance (LSPR) from the maintained triangular shape, the controllable Au–Ag alloy composition, and the increased surface roughness. The NIR light extinction enables an active photothermal effect as well as a high photothermal conversion efficiency (78.5%). The well-maintained triangular shape, surface-roughened evolutions of both micro- and nanostructures, and tunable NIR surface plasmon resonance effect enable potential applications of the Au–Ag alloy nanoplates in surface-enhanced Raman spectroscopic detection of biomolecules through 785-nm laser excitation.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2014
·Vol. 38
·期 8
·3999-4006
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IF 3.159
Zhenzhen Wang,Shangru Zhai,Bin Zhai,Zuoyi Xiao,Feng Zhang,Qingda An
Novel protocol towards multifunctional magnetic organic–inorganic core–shell nanostructured catalysts of Fe3O4@SN/HPW@CG–Ag with tailored properties are presented in this work. Such nanocomposites congregate the properties and functions of a single component into a whole. For instance, Fe3O4 cores protected by amino-functionalized SiO2 shell endowed the composites with superparamagnetism (28.6 emu g−1) and thereby facilitate the process of separation and recovery. Phosphotungstic acid, as a bridging agent, provided a strong interaction for the anchoring of glutaraldehyde cross-linked chitosan onto the surface of Fe3O4@SN. More interestingly, chitosan could simultaneously behave as a stabilizer and reductant for the in situ synthesis of “green” Ag NPs without addition of any other reducing agent or organic solvent, and Ag NPs provided the compounds with a catalytic performance. Further the size, loading of Ag NPs and the thickness of the chitosan layer were all controllable. Meaningfully, the as-synthesized catalyst Fe3O4@SN/HPW@CG–Ag exhibited an exceptional catalytic performance for the reduction of 4-nitrophenol in the presence of sodium borohydride (the reaction was accomplished within 7 min) and could be reused at least 10 times with good stability by means of convenient magnetic separation. Thence, the design philosophy of the multifunctional robust Ag-based nanocatalysts may pave the way for the synthesis of other catalyst systems with long-term stability.
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高影响因子
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