查找使用阿拉丁产品的科研文献

Surface deposition of Ag/Ag3VO4 on rod-like BiPO4 to construct plasmon-induced heterostructures with ameliorated photocatalytic performance

Hongjun Fang,Yusong Pan,Haixian Yan,Linfeng Xu,Chengling Pan

Novel plasmonic photocatalysts have been extensively investigated because of their advantages in efficient light absorption and surface plasmon resonance effect (SPR). Herein, plasmon-induced BiPO 4 /Ag/Ag 3 VO 4 heterostructures were constructed by in-situ partially reduction along with hydrothermal approach. Photo-degradation results revealed that BiPO 4 /Ag/Ag 3 VO 4 -1.2 (abbreviation as Bi/Ag-1.2) product presented a significant enhancement of photoactivity for Methyl orange-MO, Congo red-CR and tetracycline-TC degradation under visible light irradiation, which was higher than that of pristine BiPO 4 and Ag/Ag 3 VO 4 , respectively. Moreover, this excellent performance of Bi/Ag-1.2 was mainly ascribed to the synergistic effect consisting of intimate heterostructure between BiPO 4 and Ag/Ag 3 VO 4 and SPR effect of Ag, thus ensuring an accelerated separation and transfer of photo-generated carriers and promoting the absorbance of visible light. The trapping test and electron spin resonance further demonstrated that h + and ·O 2 − species are the vital active species in the photocatalytic reaction. Meanwhile, a plausible photocatalytic mechanism induced by plasmon-based heterojunctions was systematically proposed.

In-situ preparation of Ferrero® chocolate-like Cu2O@Ag microsphere as SERS substrate for detection of thiram

Chengli Yao,Xinna Gao,Xuan Liu,Yuhua Shen,Anjian Xie

It is a challenging and valuable work to synthesize surface enhanced Raman scattering (SERS) substrate with low cost and high performance by simple methods, and use it to detect pesticide residues in food. Here, Ferrero® chocolate-like Cu 2 O@Ag microspheres (FRC-Cu 2 O@Ag) were fabricated by a facile in-situ redox reaction. Cu 2 O directly acted as templates and reducing agents to induce the nucleation and growth of Ag nanoparticles on the microspheres surfaces. The prepared semiconductor-noble metal hybrids of Cu 2 O@Ag were utilized as SERS substrates to detect 4-mercaptobenzoic acid (4-MBA) and thiram molecules. The distinguished SERS effect was achieved when target molecules absorbed on the FRC-Cu 2 O@Ag composite. The substrate presented excellent sensitivity and reproducibility for the detection of 4-MBA and thiram with the limit of 10 −10 and 10 −9  M, respectively. Due to combining both advantages of electromagnetic enhancement of Ag metals and chemical enhancement of Cu 2 O semiconductors, the obtained FRC-Cu 2 O@Ag microspheres provided a SERS platform to conveniently detect molecules with thiol groups. When it was applied to detect thiram residues on apple peel and the detection limit was 1.2 × 10 −7  M, low than maximal residue limit (MRL) of 7 × 10 −6  M in fruit prescribed by the U.S. Environmental Protection Agency (EPA).

Synergistic and On-Demand Release of Ag-AMPs Loaded on Porous Silicon Nanocarriers for Antibacteria and Wound Healing

Yao Jin,Yudong Yang,Wei Duan,Xuetong Qu,Jianmin Wu

Due to the abuse of antibiotics, antimicrobial resistance is rapidly emerging and becoming a major global risk for public health. Thus, there is an urgent need for reducing the use of antibiotics, finding novel treatment approaches, and developing controllable release systems. In this work, a dual synergistic antibacterial platform with on-demand release ability based on silver nanoparticles (AgNPs) and antimicrobial peptide (AMP) coloaded porous silicon (PSi) was developed. The combination of AgNPs and AMPs (Tet-213, KRWWKWWRRC) exhibited an excellent synergistic antibacterial effect. As a carrier, porous silicon can efficiently load AgNPs and AMP under mild conditions and give the platform an on-demand release ability and a synergistic release effect. The AgNPs and AMP coloaded porous silicon microparticles (AgNPs-AMP@PSiMPs) exhibited an acid pH and reactive oxygen species (ROS)-stimulated release of silver ions (Ag+) and AMPs under bacterial infection conditions because of oxidation and desorption effects. Moreover, the release of the bactericide could be promoted by each other due to the interplay between AgNPs and Tet-213. In vitro antibacterial tests demonstrated that AgNPs-AMP@PSiMPs inherited the intrinsic properties and synergistic antibacterial efficiency of both bactericides. In addition, wound dressing loaded with AgNPs-AMP@PSiMPs showed outstanding in vivo bacteria-killing activity, accelerating wound-healing, and low biotoxicity in aStaphylococcus aureus-infected rat wound model. The present work demonstrated that PSiMPS might be an efficient platform for loading the antibiotic-free bactericide, which could synergistically and on-demand release to fight wound infection and promote wound healing.

Modification of Catalytic Properties of Hollandite Manganese Oxide by Ag Intercalation for Oxidative Acetalization of Ethanol to Diethoxyethane

Jie Ding,Liang Huang,Guojing Ji,Yuewu Zeng,Zhaoxu Chen,Eric G. Eddings,Maohong Fan,Qin Zhong,Harold H. Kung

The effect of addition of Ag to the catalytic properties of hollandite manganese oxide (HMO) was investigated for the oxidative acetalization of ethanol to diethoxyethane. Based on analysis with HRTEM, XRD, and EXAFS, Ag introduced onto HMO by deposition/precipitation was found to be present in different forms in the final catalyst depending on the calcination temperature. It could exist as nanoparticles on the outside surface of HMO nanorods for samples calcined at 60 °C, and as Ag atoms intercalated into the tunnels of the HMO structure for samples calcined at 500 °C. NH3 desorption results showed that intercalation of Ag resulted in stronger Lewis acidic sites on HMO, which DFT computational results suggested to be due to Ag-induced electron redistribution in the HMO framework. The intercalation of Ag atoms also made the HMO more easily reducible by lowering the H2 reduction temperature from 500 to 200 °C. Consequently, the sample with intercalated Ag was more active for ethanol oxidation to acetaldehyde, achieving nearly 100% conversion of ethanol and acetaldehyde by 360 °C, and acetalization of acetaldehyde with ethanol to produce diethoxyethane selectively, resulting in 93.5% diethoxyethane yield, which was 10% higher than with samples containing Ag nanoparticles on HMO. This study demonstrated a little-studied phenomenon in which a metal alters the catalytic properties of an oxide electronically but not structurally and without direct participation in the reaction.

Emission tuning of highly efficient quaternary Ag-Cu-Ga-Se/ZnSe quantum dots for white light-emitting diodes

Jinxin Wei,Zhe Hu,Wenjie Zhou,Yi Qiu,Hanqing Dai,Yuanyuan Chen,Zhongjie Cui,Siyu Liu,Haiyang He,Wanlu Zhang,Fengxian Xie,Ruiqian Guo

With the blooming development of zero-dimensional nanomaterials , I-III-VI alloying quantum dots (QDs) with outstanding photoelectrical properties have emerged to attract much attention as promising environmentally-friendly substitutions for conventional binary Cd-based QDs. In this work, a facile one-pot method was introduced to synthesize unreported quaternary Ag-Cu-Ga-Se/ZnSe (ACGSe/ZnSe) QDs. A relatively high photoluminescence quantum yield (PL QY) of 71.9% and a tunable emission from 510 to 620 nm were successfully achieved. We explored the roles of alloying compositions in ACGSe/ZnSe QDs, inferring that increased Ag proportion would not only lower the V defect level which leads to the blue shift of emission, but also slow the ZnSe shelling process owing to the larger lattice distortion. At last, the white light-emitting diodes (WLEDs) were fabricated with ACGSe/ZnSe QDs as the conversion layer, indicating that the as-prepared QDs are a promising candidate for further applications.

Bi2MoO6/TiO2 heterojunction modified with Ag quantum dots: a novel photocatalyst for the efficient degradation of tetracycline hydrochloride

Zhuangzhuang Yin,Shihan Qi,Shangkun Deng,Kang Xu,Zhu Liu,Miao Zhang,Zhaoqi Sun

In this study, a Bi 2 MoO 6 /TiO 2 heterojunction photocatalyst modified with Ag quantum dots was successfully synthesized. The results demonstrated that Ag–Bi 2 MoO 6 /TiO 2 exhibited excellent photoelectrochemical performance and photocatalytic activity for the degradation of tetracycline hydrochloride. The catalyst had the best photocurrent density with a maximum value of 103.0 µA/cm 2 , which was 11.7 times higher than that of unmodified TiO 2 nanorods. Ag–Bi 2 MoO 6 /TiO 2 significantly increased the absorption intensity and red-shifted with a bandgap of 1.88 eV, which is substantially narrower than that of TiO 2 . Furthermore, it exhibited extremely high photocatalytic activity for the degradation of tetracycline hydrochloride with a degradation rate of 90.8% at 120 min. A photocatalytic mechanism was proposed to explain the principle of tetracycline hydrochloride degradation using this catalyst.

Fiber-Optic Surface Plasmon Resonance Sensor for Trace Cadmium-Ion Detection Based on Ag-PVA/TiO2 Sensing Membrane

Ting Li,Wenlin Feng

GO/Au@Ag nanobones decorated membrane for simultaneous enrichment and on-site SERS detection of colorants in beverages

Lili Kong,Jie Chen,Meizhen Huang

In this paper, we have developed a graphene oxide/Au@Ag nanobones membrane (GO/Au@Ag NBs membrane) for simultaneous enrichment and SERS detection of colorants in beverages. Raman enhancement effect of Au@Ag nanobones (NBs) and enrichment capability of graphene oxide (GO) are contributed to the high sensitivity of GO/Au@Ag NBs membrane. Microporous membrane provides a support template for uniformly loading high-density GO/Au@Ag NBs. When beverage flow through the portable filtration unit with GO/Au@Ag NBs membrane, colorant molecules could be efficiently enriched. The prepared GO/Au@Ag NBs membrane exhibits an excellent sensitivity with a LOD of Rhodamine 6 G at 1.12 × 10 −9 mol/L, and has good performances of uniformity (with an RSD of 7.87 %), repeatability (with an RSD of 10.44 %), time stability (stored up to 60 days). Six types of colorants were sensitively detected combined with GO/Au@Ag NBs membranes, portable filtration unit and self-development portable Raman system. The lowest distinguished amounts of molecular accumulation are well below the maximum usage limits and the limits of visual recognition. Support vector machine model was established to identify the types of colorants, including colorants with coincident Raman peaks or similar visual colors, with an average accuracy of 94.8 %. In addition, GO/Au@Ag NBs membranes were used to enrich and detect colorant additives in commercial beverages, brilliant blue in energy beverage and carmine in bayberry wine were successfully detected. These results indicate GO/Au@Ag NBs membranes combined with a portable filtration unit can effectively enrich and rapidly detect colorants in beverages, and has great potential in the field of on-site and sensitive food safety detection.

A highly sensitive and selective colorimetric/fluorescent probe for the detection of Ag+ based on a croconium dye

Hong Wang,Yuehan Wu,Yuzhe Zhang,Man Zhou,Song Xu,Zhongyu Li

A novel colorimetric and fluorescent probe, 2,5-bis[3-ethyl-2-methylbenzothiazole]-croconine ( BBC ) has been synthesized and characterized. The BBC dye can effectively recognize Ag + in the presence of potentially competitive metal ions (Co 2+ , Na + , Cd 2+ , K + , Mg 2+ , Zn 2+ , Ca 2+ , Ba 2+ , Ni 2+ , Cr 3+ , Al 3+ ), which exhibited visible color change and fluorescence spectra behaviors. The Benesi-Hildebrand plot accurately showed the binding constant of BBC- Ag + . Correspondingly, the 1:1 stoichiometric structure of BBC and Ag + was evaluated by using Job’s plot. Moreover, the complex mechanism of BBC toward Ag + were also investigated by Fourier transform infrared (FT-IR) and 1 H nuclear magnetic resonance ( 1 H NMR). The results indicated that BBC could be used as a high effective colorimetric and fluorescent sensor to identify Ag + .

Facile preparation of Fe3O4/Ag/RGO reusable ternary nanocomposite and its versatile application as catalyst and antibacterial agent

Teng Chen,Yunlong Geng,Hongri Wan,Yan Xu,Yingmei Zhou,Xiangjun Kong,Jiaomei Wang,Yunhui Qi,Bing Yao,Zhaojian Gao

In this paper, Fe 3 O 4 /Ag/RGO reusable ternary nanocomposites are explored via a facile one-pot solvothermal strategies, and the catalytic performance and antibacterial activity are investigated in detail. The catalytic performance of Fe 3 O 4 /Ag/RGO towards the reduction of 4-NP into 4-AP is evaluated, and the reaction rate constant ( k ) for Fe 3 O 4 /Ag/RGO is calculated to be 0.03086 s −1 , which is higher than that of Fe 3 O 4 /Ag (0.01756 s −1 ), indicating the catalytic activity is improved after decorating Fe 3 O 4 /Ag onto the graphene sheet. The antibacterial experiment shows Fe 3 O 4 /Ag/RGO ternary nanocomposites present a wide range of antibacterial activities against Gram-positive bacteria ( S. aureus and B. cereus ) and Gram-negative bacteria ( E. coli and P. aeruginosa ). The minimal inhibitory concentrations (MIC) for Fe 3 O 4 /Ag/RGO nanocomposites against four bacterial species are determined. Additionally, Fe 3 O 4 /Ag/RGO nanocomposites also present high reusability as catalyst and antibacterial agent. The results illustrated in this paper imply that the multifunctional performances such as efficient reduction of 4-NP followed by superior anti-reproduction of pathogenic bacteria make the Fe 3 O 4 /Ag/RGO ternary nanocomposites a promising catalyst for dye-polluted water and disinfectant agent for wastewater treatment and purification.

A sensitive “off-on” carbon dots-Ag nanoparticles fluorescent probe for cysteamine detection via the inner filter effect

Xiaowei Mu,Minxing Wu,Bo Zhang,Xin Liu,Shaomei Xu,Yibing Huang,Xinghua Wang,Daqian Song,Pinyi Ma,Ying Sun

In this study, we describe the construction of an “off-on” fluorescent probe based on carbon dots (CDs) and silver nanoparticles (AgNPs) mixture for sensitive and selective detection of cysteamine . By mixing AgNPs with CDs solution, the fluorescence of CDs was significantly decreased due to the inner filter effect (IFE). Upon addition of cysteamine to the mixed aqueous of CDs and AgNPs, the silver-sulfur bond between cysteamine and AgNPs caused AgNPs to aggregate, and the quenched fluorescence of CDs could in turn be recovered. The probe was employed to quantitatively detect cysteamine, and the results showed that it could detect cysteamine in a concentration range of 2–16 μM with the detection limit of 0.35 μM (signal-to-noise ratio of 3). The detection of cysteamine spiked into bovine serum samples showed high recovery rates ranging from 95.5 to 111.7%. More importantly, the developed probe had low cytotoxicity and was successfully used for in vivo imaging of HepG2 cells.

Green Synthesis of Cellulose Nanofibrils Decorated with Ag Nanoparticles and Their Application in Colorimetric Detection of l-Cysteine

Zhencheng Yu,Chuanshuang Hu,Litao Guan,Weiwei Zhang,Jin Gu

In this study, we reported an environmentally benign method for the synthesis of silver nanoparticles (AgNPs) by using 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibrils (CNFs) as the only reducing agent and stabilizer under mild aqueous conditions. The AgNPs were tightly adhered to the CNF surface, and the resulting stable CNF–AgNP suspension can be used for rapid and selective detection of l-cysteine (Cys). The efficacy of the process relies upon the surface plasmon resonance properties of AgNPs and the aggregation effect of AgNPs in the presence of Cys. Under optimal ionic strength provided by NaCl, Cys interacted with AgNPs, leading to a change in yellow color of the CNF–AgNP to purple. The colloidal suspension showed high sensitivity (limit of detection of 49 nM) and rapid (5 min) and selective detection of Cys among 20 amino acids that make up human proteins, hence demonstrating great potential for analyzing practical samples.