TALANTA
·
2018
·
IF 4.244
Kaiqiang Wang,Da-Wen Sun,Hongbin Pu,Qingyi Wei
Plasmonic core-shell nanomaterials have attracted great attention and offered wide applications in surface-enhanced Raman spectroscopy (SERS) due to their unique localized surface plasmon resonance (LSPR) characteristics. In this study, the SERS performance of Ag coated Au nanoparticles aggregates (Au@AgNAs) substrate was explored. The fabrication of Au@AgNAs involved using spherical Au nanocrystals of 32 nm in diameter as the seeds, and ascorbic acid was used as the reductant. The thickness of the Ag shell deposited onto the Au surface was finely tuned from 3 to 13 nm by changing the amount of AgNO 3 precursor. Results in this study suggested that the LSPR of the Au core was rapidly attenuated with increasing Ag shell thickness, while the LSPR bands for Ag shell blue-shifted from 390 to 420 nm. Au@AgNAs with the Ag shell thickness of 8.5 nm exhibited excellent SERS activity, which could realize detecting R6G at an ultralow concentration of 1 × 10 −12 M. Besides, the prepared Au@AgNAs showed well homogeneity and reproducibility, and the limit of detection of thiram was calculated as 1.09 × 10 −9 M, indicating that the Au@AgNAs substrate could be potentially used for high-performance SERS sensing applications.
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高影响因子
ACS Applied Electronic Materials
·
2019
·
IF 0
Weihao Wang,Qiufan Liao,Xiaoli Peng,Qiaoqi Lu,Zhao Li,Tao Zhang,Fengzhi Wang,Xinhua Pan,Yu-Jia Zeng,Zhizhen Ye
Tin monoxide (SnO) is a p-type semiconductor which is promising in field effect transistors (FETs) applications. However, nanostructure SnO has hardly been applied in FETs due to its stability issue. Herein, oleylamine protected Ag@SnO core–shell nanostructures have been synthesized by a hydrothermal method and configured as FETs. X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy measurements are carried out to confirm the formation of pure phase SnO. The Ag@SnO core–shell single nanostructure FETs and thin film transistors are successfully fabricated on Si/SiO2 substrates. The doping of Ag in SnO and the formation of Schottky junction between SnO and Ag effectively improve the performance of FETs. The Ag nanowire (NW) core provides the unhindered carrier transport route, and the Schottky junction formed between Ag NW and SnO effectively constrains the leakage current. The nanostructure FETs show typical p-type characteristics with a premium on/off ratio (Ion/Ioff) of 3.3 × 105, a subthreshold swing of 0.09 V dec–1 and a high p-type field effect mobility (μFE) of 1.93 cm2 V –1 s –1. The excellent properties of Ag@SnO NWs FETs promise to be important for the next-generation p-type FETs.
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RSC Advances
·
2019
·Vol. 9
·期 9
·5100-5109
·
IF 3.049
Wenxue Li,Qianlin Chen,Xianyu Lei,Shang Gong
Herein, Ag/AgBr/Ag3VO4 composites were synthesized by a simple continuous precipitation method. The obtained composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy and photoluminescence spectroscopy (PL). Photocatalytic performance of the composites was assessed by the degradation of methyl orange (MO) and tetracycline hydrochloride (TC) under visible light, and the effects of different nominal mass ratios of AgBr and Ag3VO4 on the photocatalytic activity were investigated. The results showed that after 20 min of visible light irradiation (λ > 420 nm), the removal rate of MO in the presence of a 5 : 1 sample reached 98.6%. The EIS and photocurrent results demonstrated that the enhancement of the visible light photocatalytic activity was attributed to the efficient electron–hole pair separation. In addition, the scavenging reactions conducted via the addition of different scavengers confirmed that h+ and ·O2− were the main active species in the reaction. The present study offers potential for the degradation of contaminants.
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高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Lili Ling,Yawei Feng,Hao Li,Yao Chen,Jieya Wen,Jian Zhu,Zhenfeng Bian
In this work, Ag/TiO 2 composite was prepared by photo-reduction method. The study of photocatalytic degradation of different organic pollutants found that microwave can enhance the photocatalytic degradation rate . Further studies have shown that photo-generated holes are the main active species involved in photocatalytic degradation. Under microwave irradiation , silver nanoparticles can not only promote the charge separation process, but also enhance the adsorption of organic pollutants on the surface of TiO 2 .
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ACS Omega
·
2019
·
IF 2.584
Lian Hu,Tianning Xu,Huaxin Zhu,Chaoqun Ma,Guoqing Chen
Enhanced luminescence of an emitter on a Ag film is usually ascribed to the resonant surface plasmons. In these studies, the solid cadmium sulfide (CdS) and cadmium selenide (CdSe) quantum dot/silver (QD/Ag) hybrids were prepared, and the luminescence characteristics of these QD/Ag hybrids were measured. It is found that the enhancement of the trap state emission (TSE) is related to the QD size. The TSE features of the annealed QD/Ag hybrids are insensitive to the morphology of the Ag film. We used the wet and dry methods to separate the QD and Ag components and found that the photoluminescence (PL) of the QD component was permanently changed from the initial state. The PL modification is ascribed to the Ag+ doping effect rather than the surface plasmons. This doping method uses pure Ag as the Ag+ ion source. In this case, though the CdS and CdSe QD/Ag hybrids are the solid state, the cation exchange between Ag+ and Cd2+ ions can still occur on the QD surface. Even a small amount of Ag can efficiently influence the luminescence of the QDs embedded in the poly(methyl methacrylate) matrix. A hypothetical model was proposed to explain the PL modification of the QD/Ag hybrid with and without annealing. Using this dry method for doping, the transparent luminescence label can be prepared easily, and the doped QDs can be further doped with Ag+ dopants.
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高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2019
·
IF 4.182
Qiuliang Wang,Yunfei Liu,Qiuyu Meng,Yiling Zhu,Jun Xie,Yali Luo,Yinong Lyu
Porous carbons with predefined porosity and customizable pore structures are promising templates for the synthesis of highly dispersed metal nanoparticles . Herein, nitrogen-rich hierarchical porous carbon was synthesized using rationally designed microporous organic polymer as the precursor by high-temperature treatment with potassium hydroxide activation. Due to the meso-microporous structure and high Brunauer-Emmett-Teller (BET) surface area (2585 m 2 g −1 ), the resulting porous carbon has been employed as the catalyst support and silver nanoparticles (Ag NPs) were evenly dispersed on the surface or embedded within carbon matrix. Compared with polymer precursor-supported silver nanoparticles , the porous carbon-supported silver nanoparticles show higher catalytic activity in 4-nitrophenol reduction, which can be attributed to the smaller silver particles size (3.9 nm) and the hierarchical porous structure of the support material. The pseudo-first-order rate constant (k) and catalytic activity parameter (turnover frequency, TOF) is estimated to be 8.7 × 10 −1 min −1 and 1.90 × 10 −5 mol g −1 s −1 , respectively. This is the highest value reported to date for Ag-based catalysts. More importantly, the porous composite catalyst is highly stable, easy to recycle and reused without losing its catalytic activity. The present work opens new opportunities for the design and preparation of metal nanoparticles/porous carbon composite materials.
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高影响因子
Journal of Coatings Technology and Research
·
2018
·Vol. 15
·期 3
·593-602
·
IF 1.619
Li Lin,Wang Yunli,Zhu Yingchun
Metallocene polyethylene/nano-silver coatings were prepared by a facile air-spray method on polymer films. Different from the prevailing strategy to endow polyethylene with antibacterial performance, we used metallocene polyethylene sol and nano-silver as a precursor to deposit coatings on polymers at a relatively low operating temperature. Antibacterial coatings with excellent mechanical properties, water resistance, and low silver release were achieved. The composite coatings were examined in terms of surface characteristics, mechanical properties, and antibacterial activity against two representative bacterial strains including Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ). The composite coatings exhibited favorable microstructure, good mechanical properties, and suitable crystallinity. The antimicrobial tests indicated that the fabricated composite coatings showed promising antibacterial activity against E. coli and S. aureus . Furthermore, Ag ions released by the composite coating after 30 days were under 1.2 ppb. These results indicated a promising prospect of the composite coating for wide antibacterial applications.
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高影响因子
NANO
·
2018
·
IF 1.1
Jianchao Wang,Hongsheng Luo,Xuliang Song,Xihong Zu,Jie Zhang,Yuxin Gu,Guobin Yi
In this paper, a superhydrophobic Ag–Cu composite metal film was fabricated as surface-enhanced Raman scattering substrate. Ag–Cu composite metal film was prepared from galvanic displacement on commercial copper foil. The prepared silver films were modified by PFDT to create a stable superhydrophobic SERS platform. Superhydrophobic substrates were characterized by a variety of characterization methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Vis, XPS and Raman spectra. The superhydrophobic substrate could enrich probing molecules with the volatilization of solvent. Mathematical model was presented and applied to investigate concentration factor of hydrophobic substrate. The measurements were in good agreement with the calculation results. The superhydrophobic Ag–Cu composite metal film can reduce the detection limits and provide a new way to prepare efficient SERS substrates for ultra-low concentration detection.
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高影响因子
Advanced Materials Interfaces
·
2018
·Vol. 5
·期 11
·1800183
·
IF 4.834
Zhu Xiong,Tiantian Li,Fu Liu,Haibo Lin,Yun Zhong,Qing'an Meng,Qile Fang,Habib Sakil,Weijie Song
Chinese knot is a “traditional handicraft art” in Chinese culture, which is expected to ward off evil spirits and pray for good luck. It is constructed by weaving cords and tying different types of knots firmly. Inspired by Chinese knot, a robust 1D Ag nanowire membrane with nanoscale knots is fabricated to achieve robust catalytic/anti-bacterial separation. Silver mirror reaction is manipulated to anchor Ag nanowires on a hierarchical polyvinylidene fluoride membrane substrate. The robust Ag nanowire membrane withstands the vigorous cross-flow hydraulic shear (3000 mL min −1 ) for 24 h at 0.1 MPa without any physicochemical deterioration. The Chinese knot inspired membrane exhibits extraordinary robustness in continuous catalysis, “kill-release” anti-bacteria, oil-in-water emulsion, and ultrafiltration separation. This work paves a new way for constructing a robust 1D inorganic nanowire membrane for water remediation applications.
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MATERIALS CHEMISTRY AND PHYSICS
·
2018
·
IF 2.21
Xuan Hao,Xianhui Wang,Simin Zhou,Hui Zhang,Mabao Liu
To reduce the aggregation of graphene, Ag particles were introduced in the graphene nanosheets by chemical reduction method, and the silver matrix composite reinforced with Ag-doped graphene nanosheets were fabricated by powder metallurgy . The synthesized Ag-doped graphene were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy (Raman) and X-ray photoelectron spectroscopy (XPS), and the relative density, hardness along with electrical conductivity of the silver matrix composite reinforced with Ag-doped graphene were measured as well. The results show that silver ions and graphene oxide can be effectively reduced by ascorbic acid simultaneously, most of oxygen functional groups on the Ag-doped graphene sheets can be removed dramatically, and Ag-doped graphene inhibit the graphene aggregation effectively. Compared with pure Ag, the hardness of the 0.5 wt% Ag-doped graphene reinforced sliver matrix composite is increased by 35.1% and the electrical conductivity reaches up to 98.62% IACS (International Annealed Copper Standard). However, excessive addition of Ag-doped graphene is not beneficial for the improvement on the hardness and electrical conductivity of silver matrix composite.
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Polymers
·
2018
·Vol. 10
·期 1
·59
·
IF 2.935
Wenqiang Wang,Xi Chen,Chu Zhao,Bowu Zhao,Hualin Dong,Shengkui Ma,Liying Li,Li Chen,Bin Zhang
A blend of Polyvinylidene Fluoride (PVDF) and SiO2microspheres inN,N-Dimethylformamide (DMF) underwent phase inversion to form a PVDF/SiO2membrane with SiO2microspheres in the membrane’s pores. Subsequently, the SiO2microspheres have been used as platforms for in site Ag nanoparticles (NPs) synthesis, forming a composite membrane. Benefitting from the full exposure of Ag NPs to the reactants, the composite membrane shows high catalytic reactivity when catalyzing the reduction ofp-nitrophenol under a cross-flow. The catalytic reaction follows the first-order kinetics, and the reaction rate increases with an increase in the amount of Ag NPs in the membrane, the reaction temperature, and the operating pressure. What is more, highly purified products can be produced and separated from the reactants in a timely manner by using the composite membrane.Keywords:Ag nanoparticles;catalysis;composite membrane;separation;SiO2microspheres
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Tingting Bai,Peng Lu,Zhirui Guo,Lu Xiang,Lianke Liu
Hydroquinone (HQ) can quickly reduce Au or Ag precursors only in the presence of preformed metallic seeds at room temperature without stabilizing effects and therefore is appealing for controllable synthesis of citrate-stabilized spherical Ag or Au nanoparticles (NPs). In this work, we examined the conventional room-temperature growth of citrate-stabilized Ag NPs through hydroquinone reduction in the presence of NaBH 4 -reduced Ag seeds. By control experiments and electron microscopy analysis, we reveal that this growth process is essentially under kinetic control, unlike those of Au NPs. As a result, the final Ag NPs contain a mass of kinetically favored plate-like nanostructures. Further evaluation experiments found that the selective reducibility of HQ remains at elevated temperatures. Inspired by this, we developed a thermal seeding approach for uniform citrate-stabilized Ag NPs with tunable diameters over the range 15–150 nm by simply altering the amount of Ag seeds, without previously necessary multi-cycle growth or multi-parameter adjustment.
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