JOURNAL OF SOLID STATE CHEMISTRY
·
2023
·
IF 3.3
Ji Xiang,Chuancui Yang,Ke Yang,Jin Qian,Yanzhen Lu,Qihua Zhou,Fangkuo Wang
As catalysts, metal nanoclusters (NCs) have become the focus of research due to their precise structure and excellent catalytic activity. In general, it can greatly improve the catalytic activity of NCs by thermal treatment. In this work, the ZnO supported 2,4-dimethylbenzenethiol-protected-[Ag 25 (C 8 H 9 S) 18 ] - NCs (Ag 25 @ZnO) nanocatalysts were subjected to activation temperatures of 100 °C, 200 °C and 300 °C to remove the surface ligands of Ag 25 NCs and regulate the surface composition of Ag 25 @ZnO nanocatalysts. The structure of Ag 25 @ZnO nanocatalysts were characterized by XRD , SEM, TEM, EDS and XPS. In particular, the XPS results obviously confirmed that the concentration of Ag + on the catalyst surface was positively correlated with the activation temperature. Finally, the effect of the Ag + content on the catalytic activity of the Ag 25 @ZnO nanocatalysts was also explored. Because the content of Ag + in Ag 25 @ZnO-300 nanocatalysts is the highest, the 4-nitrophenol reduction reaction showed the best catalytic performance.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Ling Pan,Song Ye,Ruihao Huang,Meiyan Wang,Peixuan Lin,Haoran Zhang,Deping Wang
Faujasite (FAU) zeolites with abundant exchangeable sites are ideal hosts for the intake of Ag+ and the stabilization of highly luminescent silver nanoclusters (Ag NCs), while theoretical calculations on the spectral characteristics, charge states, and electronic energies of Ag NCs that are confined inside FAU zeolite were seldom reported. In this research, the Na-type FAU zeolites with varying silicon-to-aluminum (Si/Al) ratios were first synthesized with the hydrothermal method and then applied as matrixes to stabilize Ag NCs to obtain tunable emissions. With the decrease in the Si/Al ratio, the Ag NCs show red-shifted emission from 515 to 548 nm and broadened photoluminescence of excitation (PLE) and photoluminescence (PL) spectral profile. The time-dependent density functional theory (TD-DFT) method was carried out to probe the effect of Al substitution on the charge states and the optical properties of Ag NCs confined inside the double-six ring (D6r) cavity. The simulated results of the absorption spectra and energy levels suggest that the S1 → S0 transition of the monovalent Ag3+ cluster is responsible for the visible emission, and the increased full width at half-maximum (fwhm) of the PLE and PL spectra in the low Si/Al ratio FAU zeolites is due to the inhomogeneous broadening brought by the increased isomer numbers of the Al-substituted neutral zeolite framework. It is noted that the peak of the simulated absorption spectra red-shifted with the decrease in the Si/Al ratio, which is consistent with the experimental observation. This research provided an effective method for the manipulation of Ag NC emission in FAU zeolites through framework cation substitution and meanwhile theoretically explained the Si/Al ratio dependence of tunable emission properties, which may benefit the design of zeolite-confined Ag NCs with desirable optical performances.
研究领域:
材料科学
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化学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Jianzhong Yu,Song Ye,Huazhen Liao,Xinling Xv,Deping Wang
Silver nanoclusters (Ag NCs) are emissive centers that are characteristic of high quantum yield, tunable emission, and large Stokes shift when confined inside zeolites, and their luminescence property is closely related to the cluster size, charge state, local environment, and extra activation. In this research, we evaluated the luminescence response of Ag NCs on the extra-framework cations by considering Na-type FAU-Y (NaY) as the parent zeolite. The extra-framework cations Na+ were partially substituted with Li+ or Ca2+ through the ion-exchange method and analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) measurements, based on which a series of MYAg (M = Na, Li, Ca) zeolites were prepared through subsequent Ag+ exchange and thermal treatment under 600 °C for 2 h. The influence of extra-framework cations on the lattice parameter of the host zeolite, the exchange efficiency of Ag+, the formation ability, and the chemical state and luminescence property of Ag NCs was studied through the combination of structural and spectral measurements. This research indicated a flexible pathway for manipulating the luminescence property of Ag NCs, and the extra-framework cation-dependent luminescence property enables the FAU-Y zeolite to become a desirable host for the stabilization of Ag NCs to achieve highly efficient tunable emission.
研究领域:
材料科学
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光化学
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产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 9
·1-7
·
IF 5.479
Zhang Pu,Jia Chunyan,Zhao Yannan,Luo Honghong,Tan Xin,Ma Xiaohong,Wang Yi
Tiopronin is a widely used drug for treatment of cystinuria, rheumatoid arthritis and hepatic disorders. It is also an antidote to heavy metal poisoning and a radioprotective agent. A method is described for rapid and sensitive determination of tiopronin using DNA-stabilized silver nanoclusters (DNA–AgNCs) as a fluorescent probe. Tiopronin can selectively bind to DNA–AgNCs to form a stable Ag-S bond upon which the red photoluminescence (best measured at excitation/emission wavelengths of 590/640 nm) is quenched. The finding is used to design an assay that has a linear response in the 1–150 nM tiopronin concentration range and a 270 pM limit of detection. Compared with previously reported methods, the present approach is more rapid, highly sensitive and selective. It has been successfully applied in the detection of tiopronin in spiked urine and serum, and in pharmaceutical products (tablets and injections).
An ultrasensitive and reliable method for tiopronin assay is developed using red-emissive silver nanoclusters as a fluorescent probe. It has been successfully applied in the determination of tiopronin in biological fluids and pharmaceutical products.
研究领域:
分析化学
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生物医学
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药学
✓ 已验证
DOI
PubMed
高影响因子
Nature Communications
·
2018
·Vol. 9
·期 1
·1-6
·
IF 12.353
Cao Yitao,Guo Jiahao,Shi Run,Waterhouse Geoffrey I. N.,Pan Jinheng,Du Zhenxia,Yao Qiaofeng,Wu Li-Zhu,Tung Chen-Ho,Xie Jianping,Zhang Tierui
The synthesis of atomically precise thiolate-stabilized silver (Ag) nanoclusters is the subject of intense research interest, yet the formation mechanism of such nanoclusters remains obscure. Here, electrospray ionization mass spectrometry is successfully applied to monitor the reaction intermediates formed during the sodium-borohydride-reduction of silver 4- tert -butylbenzenethiolate (AgSPh- t Bu). We demonstrate a unique evolution route to thiolate-stabilized Ag nanoclusters mediated by Ag-thiolate clusters. The Ag-thiolate clusters form in the initial stage of reduction contain tens of Ag atoms and similar number of ligands, and they are transformed into Ag 17 (SPh- t Bu) 12 3− and Ag 44 (SPh- t Bu) 30 4− nanoclusters in the later reduction process. The number of Ag atoms in the Ag-thiolate clusters determines the reaction path to each final nanocluster product. A similar mechanism is found when silver 2,4-dimethylbenzenethiolate (AgSPhMe 2 ) is used as precursor. This mechanism differs markedly from the long-established bottom-up evolution process, providing valuable new insights into the synthesis of metal nanoclusters.
研究领域:
纳米技术
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材料科学
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化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）