COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
Shixue He,Chao Yang,Mingguang Niu,Dandi Wei,Shasha Chu,Mei Zhong,Jide Wang,Xintai Su,Lu Wang
Well-defined deposition of noble metal nanoparticles is attractive for the synthesis of heterogeneous metal catalysts with excellent activity, stability, and easy separability. Herein, a facile method combining surface coordination deposition with thermal decomposition has been proposed to fabricate Ag/CoFe 2 O 4 composites as magnetic catalysts for hydrogenation reduction of 4-nitrophenol and 2-nitroaniline. This method involved the adsorption of silver ions on cobalt-ferrous oxalate through the surface coordination, and then the thermal decomposition into Ag/CoFe 2 O 4 . The characterizations of XRD , SEM, FTIR, BET, VSM , XPS and Element mapping were utilized to reveal that Ag/CoFe 2 O 4 exhibited a magnetic saturation of 40.4 emu g −1 , a specific surface area of 58.8 m 2 g -1 , and an even distribution of metallic Ag on CoFe 2 O 4 particles. Catalytic reduction tests of 4-nitrophenol and 2-nitroaniline indicated that the Ag contents in Ag/CoFe 2 O 4 seriously affected the catalytic activity of the catalysts. Moreover, the durability test showed that Ag/CoFe 2 O 4 still preserved ∼74.6% of the initial catalytic activity even at the 20th run.
研究领域:
化学
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材料科学
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催化反应
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
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IF 6.735
Yue Guo,Yanchun Tao,Xiaowei Ma,Jing Jin,Sisi Wen,Wei Ji,Wei Song,Bing Zhao,Yukihiro Ozaki
Mercuric ion (Hg 2+ ) is a toxic metal ion in the environment, which will seriously damage the people's health. Therefore, the simple sensitive detection of Hg 2+ is of great significance. In this work, Ag-CoFe 2 O 4 /reduced graphene oxide (rGO) nanocomposites were synthesized via a one-pot microwave-assisted reaction, which can directly oxidize 3, 3′, 5, 5′-tetramethylbenzidine (TMB) to produce a light blue. Then we have developed a dual colorimetric and SERS detection of Hg 2+ based on the stimulus of intrinsic oxidase-like catalytic activity of Ag-CoFe 2 O 4 /rGO nanocomposites. It is demonstrated that the interaction between Hg 2+ and Ag nanoparticles can occur in a short time, which includes the formation of Ag-Hg alloy due to the reduction of Hg 2+ . In addition, the formation of such alloy can enhance the oxide-like activity, which makes the detection of Hg 2+ more sensitive. By using the SERS detection approach, the assay can detect Hg 2+ as low as 0.67 nM. This detection ability is much better than previous reports based on the enzyme-like catalytic reaction, which is also lower than the maximum value of Hg 2+ permitted in drinking water by the World Health Organization (WHO) (30 nM) and United States Environmental Protection Agency (EPA) (10 nM). In addition, this detection system also shows an excellent selectivity toward Hg 2+ due to the affinity of Hg to Ag-CoFe 2 O 4 /rGO nanocomposites. Therefore, this approach is potentially applicable for the sensitive determination of Hg 2+ in real environmental conditions.
研究领域:
环境科学
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分析化学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
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2025
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IF 3.6
Jian-Wu Xiao,Dong-Dong Mai,Dong-Liang Shi,Guo-Cui Bao,Yin-Qian Lu,Li-Bao Chen,Xiao-Ying Pei,Jing-Shui Xu,Fu-An He,Kwok-Ho Lam
The CoFe 2 O 4 @reduced graphite oxide (rGO) was prepared by a one-step solvothermal reaction, and then the Ag nanoparticles were deposited on the CoFe 2 O 4 @rGO by a green mild reduction reaction to form the novel Ag-CoFe 2 O 4 @rGO filler, followed by the modification of Ag-CoFe 2 O 4 @rGO using hexadecyltrimethoxysilane to form the novel H-Ag-CoFe 2 O 4 @rGO filler. The homogeneous distribution of the Ag-CoFe 2 O 4 @rGO and H-Ag-CoFe 2 O 4 @rGO fillers in the polar PVDF plastic polymer and nonpolar SBS elastomer copolymer, respectively, to form the corresponding composites was proved by SEM. The polar crystal content of the PVDF matrix in the Ag-CoFe 2 O 4 @rGO(10 wt.%)/PVDF composite was 36.13%, while the corresponding value for pure PVDF was 29.38%. The dielectric constant at 1000 Hz of Ag-CoFe 2 O 4 @rGO(10 wt.%)/PVDF and H-Ag-CoFe 2 O 4 @rGO(10 wt.%)/SBS composites was 15.54 and 2.78, respectively, while the corresponding values for pure PVDF and pure SBS were 8.39 and 2.05, respectively. Additionally, although both pure PVDF and pure SBS were non-magnetic, the magnetization values of Ag-CoFe 2 O 4 @rGO(10 wt.%)/PVDF and H-Ag-CoFe 2 O 4 @rGO(10 wt.%)/SBS composites were 0.83 emu/g and 0.47 emu/g, respectively, at 50,000 Oe. The as-prepared Ag-CoFe 2 O 4 @rGO/PVDF and H-Ag-CoFe 2 O 4 @rGO/SBS composites should have the potential for different applications including dielectric capacitors, dielectric elastomers, sensors, EMI shielding, and so on. Graphical Preparation process of CoFe 2 O 4 @rGO and Ag-CoFe 2 O 4 @rGO hybrid filler.
✓ 已验证
产品关联
DOI
高影响因子
Micro & Nano Letters
·
2021
·Vol. 16
·期 4
·257-262
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IF 1.102
Xiao Wang,Mei Wu,Chulei Zhao,Xiaochen Liao,Mengmeng Zhang,Lisha Mei,XiuWen Qiao,Chenglin Hong
Using Ag-CoFe 2 O 4 -GO nanocomposite as biosensor interface, a novel unlabelled electrochemical immunosensor was designed to detect tumour marker carcinoembryonic antigen. Here, Ag-CoFe2O4-GO was synthesized by one-pot method as an immunological probe. They have the following advantages: (1) Silver nanoparticles have a strong redox capacity under applied voltage and good biocompatibility, so they can bind more antibodies; (2) GO has a large specific surface area, which can load more Ag NPs and CoFe 2 O 4 nanoparticles, and has excellent conductivity; (3) CoFe 2 O 4 is widely favoured by researchers due to its advantages such as low production cost and simple preparation process, The prepared Ag-CoFe 2 O 4 -GO nanocomposite can amplify the electrochemical signal; (4) The presence of GO can effectively prevent the agglomeration of Ag NPs nanoparticles and CoFe 2 O 4 nanoparticles, promote the formation of electron transfer network, and contribute to the electron transfer of sensors. Under optimal condition, the current signal and the concentration of carcinoembryonic antigen were linear in the range of 1 pg mL < sp > −1 < /sp > ∼ 80 ng mL < sp > −1 < /sp , > and the detection limit was 0.3 pg mL < sp > −1 < /sp > (S/N = 3). Under certain conditions, the manufactured immunosensor has good reproducibility, selectivity and excellent stability. Thus it has certain clinical value for the detection of carcinoembryonic antigen.
研究领域:
生物医学工程
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分析化学
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纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）