Nanomaterials
·
2020
·Vol. 10
·期 5
·883
·
IF 4.324
Bonan Zhao,Zhipeng Dong,Qiyan Wang,Yisong Xu,Nanxia Zhang,Weixing Liu,Fangning Lou,Yue Wang
The size-uniformed mesoporous Ag@SiO2nanospheres’ catalysts were prepared in one-pot step via reducing AgNO3by different types of aldehyde, which could control the size of Ag@SiO2NPs and exhibit excellent catalytic activity for the hydrogenation of nitrobenzene. The results showed that the Ag core size, monitored by different aldehydes with different reducing abilities, together with the ideal monodisperse core-shell mesoporous structure, was quite important to affect its superior catalytic performances. Moreover, the stability of Ag fixed in the core during reaction for 6 h under 2.0 MPa, 140 °C made this type of Ag@SiO2catalyst separable and environmentally friendly compared with those conventional homogeneous catalysts and metal NPs catalysts. The best catalyst with smaller Ag cores was prepared by strong reducing agents such as CH2O. The conversion of nitrobenzene can reach 99.9%, the selectivity was 100% and the catalyst maintained its activity after several cycles, and thus, it is a useful novel candidate for the production of aniline.Keywords:mesoporous;Ag@SiO2;catalyst;hydrogenation;nitrobenzene
研究领域:
材料科学
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化学工程
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2020
·
IF 4.189
Tengda Shi,Zhexiang Tang,Pei Liang,Xiubing Zhang,De Zhang,Qinchao Shao,Jie Huang,Zhi Yu,Yongquan Xu,Hongping Chen
The spectroscopy of surface-enhanced Raman scattering (SERS), with its high sensitivity and specific chemical fingerprinting, has received increasing attention. A stable substrate is extraordinarily important for the trace detection of the SERS technique, but the challenge of SERS substrate production with high stability and uniformity still imposes the unavoidable barriers. In this paper, we design a multilayer core–shell-nanostructured ZrO2@Ag@SiO2 nanoparticle through liquid extraction. First, we regulated the usage of AgNO3 (1 wt %) to obtain Ag@SiO2 which is silver coated with uniform distribution; on the surface of silica, the number of silver particles is abundant. Then, we discussed the influence when different concentrations of zirconium propoxide are added on the zirconia layer’s thickness. Then, we applied FDTD simulation to explain the position of SERS “hotpots” with and without ZrO2 coating. We have found that the detection capability of ZrO2@Ag@SiO2 can be up to 10–9 M for 4-ATP; with ZrO2@Ag@SiO2 SERS substrates exposed to the atmospheric environment for up to 30 days, we could still obtain the excellent SERS signal performance contributed by the good chemical stability of ZrO2, when ZrO2 is coated on the surface of Ag@SiO2, the zirconia layer formed has a protective role . These experimental results have indicated that the outer zirconia layer could prevent the silver surface from being oxidized, ensuring its stability , which is quite crucial for the applied SERS.
研究领域:
材料科学
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光谱学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 16
·期 1
·201
·
IF 3.748
Luping Tang,Chen Liao,Yingqing Guo,Yangyang Zhang
Metal nanoparticles have attracted a great deal of interest due to their unique properties of surface plasmon resonance. Metal nanoparticles can enhance the fluorescence emission intensity of quantum dots (QDs) through the local surface plasmon resonance effect, which is mainly determined by the distance between them. Therefore, it is very important to achieve controllable distance between metal and QDs, and study fluorescence enhancement. In this work, the controllable adjustment of the distance between metal nanoparticles and QDs was successfully realized by controlling the thickness of the SiO2shell of Ag@SiO2nanoparticles. Firstly, Ag nanoparticles with uniform size distribution and relatively high concentration were prepared, and then the thickness of the SiO2shell was controlled by controlling the amount of tetra-ethyl orthosilicate (TEOS) in the hydrolysis of TEOS reaction. (3-aminopropyl) triethoxysilane (APS) was used to connect CdS/ZnS QDs with Ag@SiO2nanoparticles to form Ag@SiO2@CdS/ZnS QD composite nanoparticles. The fluorescence spectra shows that the fluorescence intensity of the Ag@SiO2@CdS/ZnS QD composite nanoparticles is significantly enhanced. Photoexcitation spectra and fluorescence spectra of CdS/ZnS QD and Ag@SiO2@CdS/ZnS QD composite nanoparticles, measured under different energy excitation conditions, indicate that the existence of Ag nanoparticles can enhance the fluorescence intensity of CdS/ZnS QDs. Finally, a further physical mechanism of fluorescence enhancement is revealed.Keywords:Ag-SiO2;fluorescence enhancement;transmission electron microscope;quantum dots;photoexcitation spectra
研究领域:
材料科学
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光学
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Feifan Chen,Bo Zhang,Weihao Cai,Nengquan Fan,Yongkang Lu,Luxia Yin,ZeKai Zhang,Wensheng Ning
Ag/SiO2–Al2O3 aerogel composites with different molar ratio of Si to Al were prepared by the sol–gel synthesis followed by drying under atmospheric pressure and then characterized by XRD, FT-IR, BET, SEM, XRF, TG-DTG, and Py-FTIR, respectively. The effect of doping Al on their physicochemical properties and adsorption desulfurization performance was investigated in comparison with Ag/SiO2. The incorporation of Al in Ag/SiO2 resulted in a gradual decrease in the specific surface area, an increase in the actual content of Ag, and an appearance of Brönsted acid centers. The actual content of Ag in Ag/SiO2–Al2O3-n increased first and then decreased with the increase in Al content. Doping Al in Ag/SiO2 led to an improvement in the adsorption capacity and the adsorptive selectivity for thiophene at the presence of toluene and cyclohexene, as well as the solvent washing regeneration performance, attributed to the adsorption of thiophenics on Ag/SiO2–Al2O3-n by π-complexation of Ag(I) and the acid–base interaction of Lewis and Brönsted centers with thiophenics simultaneously, and the increase in the actual content of Ag in the adsorbents. Ag/SiO2–Al2O3-100 had the largest adsorption capacity for thiophene and benzothiophene, 12.2 mg of S/gads (0.57 mmol of S/mmol of (Ag + Al)) and 17.7 mg of S/gads (0.53 mmol of S/mmol of (Ag + Al)), respectively.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Yao Shi,Xiao-Liang Zhang,Gang Feng,Xiangshu Chen,Zhang-Hui Lu
Ag–SiO 2 nanocomposites (NCs) with “plum-pudding” structure have been synthesized using a facile reverse micelle method. The as-synthesized Ag–SiO 2 NCs were calcined at 623 K to remove the surfactants and then characterized by XRD , FE-SEM, TEM, EDX, ICP and N 2 adsorption–desorption. The obtained results demonstrated that many ultrafine Ag nanoparticles (NPs) with size of ~2 nm are well dispersed in each SiO 2 nanosphere (28 nm). In comparison with free Ag NPs and SiO 2 supported Ag NPs, the Ag–SiO 2 NCs exhibited a better catalytic activity for the reduction of 4-nitrophenol with a turnover frequency of 489 h −1 at room temperature. Ag–SiO 2 NCs also displayed a superior catalytic activity for hydrogenation of 2-NP and 3-NP. The activation energy of Ag–SiO 2 NCs was estimated to be about 34.4 kJ mol −1 , which was lower than most of the reported values for the same reaction using Ag-based catalysts, indicating the superior catalytic performance of these plum-pudding structured catalysts.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Hao Li,Shenyue Gao,Hang Ding,Yuetong Tao,Shenghua Ma,Gang Wang,Beibei Wang
Interfacial solar steam generation is considered the next-generation desalination and sewage treatment technology. However, realizing solar evaporators with broad-spectrum absorption, efficient thermal conversion, and high stability remains a challenge. The high light-trapping surface structure and fast water transport channels of the evaporator improve the evaporation efficiency, and solar evaporators have great potential in the field of solar steam generation. Herein, the mixture of transition-metal carbide (Ti3C2Tx) and core–shell Ag–SiO2 nanoparticles (Ag@SiO2 NPs) is fabricated as a three-dimensional (3D) vertical porous Ti3C2Tx/Ag@SiO2 gel evaporator via ice templating technology. The synergistic interaction between dual Ti3C2Tx–Ag plasma materials confined in a cross-linked microcapillary structure realizes 97.6% wide absorption in the wavelength range of 250–2500 nm. The SiO2 coating on the surface of Ag NPs can inhibit the oxidation of Ag NPs and conduct heat collection management. The 3D vertically cross-linked porous structure promotes efficient water transport and improves the mechanical strength of the evaporator. The Ti3C2Tx/Ag@SiO2 gel evaporator exhibits a high evaporation rate of 1.42 kg m–2 h–1 and a photothermal conversion efficiency of 98% under 1 sun illumination. The Ti3C2Tx/Ag@SiO2 gel evaporator shows great application prospects in seawater desalination and sewage purification.
研究领域:
材料科学
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能源技术
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2018
·
IF 3.12
Yongpeng Ma,Bailong Mu,Xiaojing Zhang,Hongzhong Zhang,Haomiao Xu,Zan Qu,Li Gao
Hierarchical Ag-SiO 2 @Fe 3 O 4 magnetic composites were selected for elemental mercury (Hg 0 ) removal from non-ferrous metal smelting flue gas in this study. Results showed that the hierarchical Ag-SiO 2 @Fe 3 O 4 magnetic composites had favorable Hg 0 removal ability at low temperature. Moreover, the adsorption capacity of hierarchical magnetic composite is much larger than that of pure Fe 3 O 4 and SiO 2 @Fe 3 O 4 . The Hg 0 removal efficiency reached the highest value as approximately 92% under the reaction temperature of 150°C, while the removal efficiency sharply reduced in the absence of O 2 . The characterization results indicated that Ag nanoparticles grew on the surface of SiO 2 @Fe 3 O 4 support. The large surface area of SiO 2 supplied efficient reaction room for Hg and Ag atoms. Ag–Hg amalgam is generated on the surface of the composites. In addition, this magnetic material could be easily separated from fly ashes when adopted for treating real flue gas, and the spent materials could be regenerated using a simple thermal-desorption method.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Zelong Li,Xue Han,Lan Fu,Guochao Shi,Shiqi Xu,Mingli Wang,Wenzhi Yuan,Wenying Zhou,Jiahao Cui
The combination of surface-enhanced Raman scattering (SERS) and machine learning algorithm provides an effective means for the identification of pharmacodynamic substances. This paper reported a biomimetic synthesis route of Ag-30/SiO 2 -4/Cu-20/rice leaf (Ag-30/SiO 2 -4/Cu-20/RL) SERS platform with multiple synergistic electromagnetic enhanced performance. The localized surface plasmon resonance (LSPR) effect was strengthened as the SiO 2 nanolayer generated between Ag and Cu. This SERS platform demonstrated high sensitivity, with a low limit of detection (LOD) of 1 × 10 −10 M for 4-Aminophenylthiophenol (4-ATP) and an enhancement factor (EF) of 3.86 × 10 6 . More importantly, the principal component analysis (PCA) was adopted to analyze the SERS data of three different Traditional Chinese medicine (TCM) pharmacodynamic substances (Orientin, Atractylenolide III and Prim-o-glucosylcimifugin). The K-nearest neighbor (KNN) and Naïve Bayes (NB) achieved classification accuracy of 0.9474 and 0.9649, respectively. The platform provides guidance for the accurate identification of TCM pharmacodynamic substances.
研究领域:
分析化学
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生物医学工程
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中医药学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 10
·期 1
·265-273
·
IF 7.393
Xu Liu,Xiao-Rong Sun,Chen Luo,Hong-Zhi Ma,Hua Yu,Yan Shao,Ming-Bo Yang,Bo Yin
The development of self-powered technology in nano-energy puts forward higher requirements for triboelectric nanogenerators (TENGs), in which it is necessary to further improve their output performance to broaden their scope of application, and environmentally friendly and sustainable development needs to be realized as well by the recycling of friction materials. The preparation of environmentally friendly and sustainable TENGs is reported in this work through a feasible and cost-effective solution casting method, in which polyethylene oxide (PEO) and Ecoflex were utilized as positive/negative friction materials, respectively. With introducing micron-sized core–shell Ag@SiO2 particles into the PEO matrix, micro–nano structures were constructed to increase the effective contact area, while the enhancement of dielectric properties was also achieved in the meantime. The Ag@SiO2–PEO/Ecoflex TENG with optimum particle content of 50 wt% produced a short-circuit current of 10 μA, an open-circuit voltage of 95 V, and a transfer charges of 35 nC at a frequency of 3 Hz. The maximum output power density of Ag@SiO2–PEO-50 wt%/Ecoflex TENG up to 1.5 W m−2 was reached under different load resistances. The stability and flexibility of TENGs were verified as well, which led to a novel approach for their application in wearable-flexible electronic devices. Additionally, the sustainable utilization of TENGs was achieved as a result of the water solubility of the PEO material, with significant output performance retention. This work provides an innovative approach for the further modification of the output performance of flexible and sustainable TENGs.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
NANO
·
2018
·
IF 1.1
Zongxue Yu,Xia Min,Fei Li,Qi Chen
In the study, the Ag–SiO 2 –APTES nanocomposite was synthesized via the self-assembly method to prepare Ag–SiO 2 and subsequently used 3-aminopropyltriethoxysilane (APTES) to functionalize its surface. The as-prepared Ag–SiO 2 –APTES nanocomposite was embedded into poly(vinylidene fluoride) (PVDF) membrane by the co-blending way to fabricate the Ag–SiO 2 –APTES membrane. The Ag–SiO 2 –APTES nanocomposites were characterized by X-ray diffraction (XRD). These membrane materials were characterized by field emission scanning electron microscopy (SEM), transmission electron microscopy (TEM) and FT-IR spectra. The performance of membrane was investigated simultaneously for removing the organic dye methylene blue (MB), Rhodamine B, Direct Red 28 and anti-microbial ability. The experimental results demonstrated that the Ag–SiO 2 –APTES modified membrane were presented to be more hydrophilic with a contact angle 55.6 ∘ , whereas the pristine PVDF membrane was 81.8 ∘ . The dye rejection ratios were also improved after adding Ag–SiO 2 –APTES, which reached 86.8% for MB, 87% Rhodamine B, 88% for Direct Red 28, besides, the removal rate of MB was about 98.7% at pH = 11. More importantly, the Ag–SiO 2 –APTES membranes exhibited excellent antifouling properties for treating MB solution and could reach 85% of flux recovery ratio after four cyclic experiment. Finally, via inhibition zone method of antimicrobial test Ag–SiO 2 –APTES membrane exhibited the antimicrobial activity against Escherichia coli ( E. coli ) excellently. The novel antifouling and antibacterial Ag–SiO 2 –APTES membrane has a potential for dye wastewater treatment and water purity.
研究领域:
材料科学
·
环境工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY
·
2024
·
IF 6
Junhan Xu,Binghong Chen,Kunpeng Yuan,Jun Shu,Qiguo Yang
Ag@SiO 2 nanofluid is widely used in spectral splitting PV/T system. Its core–shell structure has great influence on the optical properties. In this work, we focus on the comprehensive analysis and structure optimization of Ag@SiO 2 nanofluid to achieve its optimal spectral performance. DDA method is used to predict the optical properties of Ag@SiO 2 nanofluid and an optimization model based on filter efficiency is proposed. The effect of the SiO 2 shell thickness and Ag core mass concentration is analyzed. It indicates that the spectral performance of Ag@SiO 2 nanofluid can be improved with SiO 2 shell thickness of 15–40 nm and Ag core mass concentration of 81–135 mg/L. To achieve the same theoretical merit function of 1.46, the usage of Ag mass can be reduced by 25/33/44/62 % with SiO 2 coating of 10/20/40/70 nm. The optimal structure to achieve the highest filter efficiency η of 37.8 % is with a shell thickness of 20 nm and a mass concentration of 113.9 mg/L. An indoor PV/T operation testing is conducted to verify the optimization results. The merit function of Ag-based nanofluids increases from 1.58 to 1.598 and a reduction in Ag usage of 17 % is achieved with a SiO 2 coating shell of 17.8 nm. Operation stability is also enhanced with no aggregation observed during the working cycle and 7-day static experiment.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Bo Li,Haocheng Yang,Hongli Song,Jie Zou,Chenchen Li,Ziyi Yan,Moyuan Qu,Wenqian Xiao,Songsong Zhu,Xiaoling Liao
Repairing bone defects is particularly challenging when an infection is presented. In this study, poly(L-lactic) (PLLA) nanofibrous microspheres (large microspheres) were used as cell carriers to simulate the nanofibrous structure of the extracellular matrix. A planet-satellite composite microsphere with large microspheres and small microspheres was constructed by bonding hollow Ag@SiO 2 nanospheres (small microspheres) to nanofibrous PLLA microspheres. According to the results, PLLA nanofibrous microspheres activated by EDC and NHS can firmly combine with Ag@SiO 2 nanospheres. The composite microspheres demonstrated excellent drug release functions, antibacterial properties, and biocompatibility and promoted cell adhesion and differentiation in vitro. The bone repair function of composite microspheres loaded with BMP2 growth factor was evaluated in rat that were infected with bacteria and exhibited skull defects. A four-week study showed that these microspheres significantly promoted bone regeneration in infected bone. These multifunctional microspheres could revolutionize bone repair and provide a much-needed solution for those suffering from infected bone defects.
研究领域:
材料科学
·
生物医学工程
·
组织工程
·
骨科
·
药剂学
✓ 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）