Nanoscale
·
2022
·Vol. 14
·期 36
·13248-13260
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IF 8.307
Xin Huang,Haitao Li,Yin Zhang,Ruifang Wu,Lijun Ban,Lin Xi,Zhifang Yin,Jian Peng,Yongxiang Zhao,Li Fang
In conventional thermocatalytic reactions under a reducing atmosphere, stabilization of the active Cu+ component and inhibition of over-reduction into metallic Cu0 are extremely challenging. In this study, Au@Cu2O core–shell nano-catalysts with different Cu2O shell thicknesses were synthesized, and the effect of the Au nano-core on Cu+ stability under a reducing atmosphere and the catalytic performance of Cu+ in the ethynylation of formaldehyde were investigated. The Au nano-core facilitates Cu2O dispersion and leads to an increase of 0.2–0.5 eV in electron binding energies of Cu2O and Cu2C2 in the range of 27–55 nm, attributed to the long-range electromagnetic effect of Au NPs. Specifically, active Cu+ centers exhibit high stability under a reducing atmosphere due to the long-range electromagnetic effect of the Au nano-core. In the ethynylation of formaldehyde as a probe reaction, Cu+/(Cu0 + Cu+) on Au@Cu2O catalysts remained at 88–91%. The catalytic performance in the ethynylation of formaldehyde revealed that the introduction of an Au nano-core into Cu-based catalysts increased the TOF from 0.37 to 0.7 h−1, and decreased the activation energy from 42.6 to 38.1 kJ mol−1. Additionally, the Cu+/(Cu0 + Cu+) ratios and the catalytic performance in the ethynylation of formaldehyde (BD yield = 65%, BD selectivity = 95%) on Au@Cu2O catalysts remained constant after nine cycles, while pure Cu2O readily deactivated due to the dramatically reduced Cu+/(Cu0 + Cu+) ratios and carbyne deposition. In summary, Cu+ in Cu-based catalysts showed high catalytic activity and stability during the ethynylation of formaldehyde due to the long-range electromagnetic effect of the Au nano-core.
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PubMed
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 34
·21875-21884
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IF 4.036
Ruimeng Sun,Ruijuan Lv,Yang Zhang,Ting Du,Yuhan Li,Lixia Chen,Yanfei Qi
The catalytic properties of bimetallic nanoparticles have been widely studied by researchers in many fields. In this paper, core–shell Cu/Au nanoparticles (Cu/Au NPs) were synthesized by a simple and mild one-pot method, and their peroxidase activity was proved by catalyzing the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) with color change to blue. The change of solution color and absorbance strongly depends on the concentration of H2O2, so it can be used for direct detection of H2O2 and indirect detection of glucose. What's more, GSH can efficiently react with the hydroxyl radicals from H2O2 catalyzed by core–shell Cu/Au NPs to inhibit the production of ox-TMB. Thus, the concentration of GSH can be determined by the decrease in the absorbance of the solution at 652 nm. The results showed that our proposed strategy had good detection range and detection limit for the detection of glucose and GSH. This method has been used in the detection of practical samples and has great application potential in environmental monitoring and clinical diagnosis.
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高影响因子
Frontiers in Pharmacology
·
2022
·
IF 5.988
Chenxi Li,Rui Liu,Yurong Song,Youwen Chen,Dongjie Zhu,Liuchunyang Yu,Qingcai Huang,Zhengjia Zhang,Zeyu Xue,Zhenglai Hua,Cheng Lu,Aiping Lu,Yuanyan Liu
Rheumatoid arthritis (RA) is a chronic inflammatory disease, characterized by synovial inflammation in multiple joints. Triptolide (TP) is a disease-modifying anti-rheumatic drug (DMARD) highly effective in patients with RA and has anti-inflammatory properties. However, its clinical application has been limited owing to practical disadvantages. In the present study, hyaluronic acid (HA) hydrogel-loaded RGD-attached gold nanoparticles (AuNPs) containing TP were synthesized to alleviate the toxicity and increase therapeutic specificity. The hydrogels can be applied for targeted photothermal-chemo treatment and in vivo imaging of RA. Hydrogel systems with tyramine-modified HA (TA-HA) conjugates have been applied to artificial tissue models as surrogates of cartilage to investigate drug transport and release properties. After degradation of HA chains, heat was locally generated at the inflammation region site due to near-infrared resonance (NIR) irradiation of AuNPs, and TP was released from nanoparticles, delivering heat and drug to the inflamed joints simultaneously. RA can be penetrated with NIR light. Intraarticular administration of the hydrogels containing low dosage of TP with NIR irradiation improved the inflamed conditions in mice with collagen-induced arthritis (CIA). Additionally, in vitro experiments were applied to deeply verify the antirheumatic mechanisms of TP-PLGA-Au@RGD/HA hydrogels. TP-PLGA-Au@RGD/HA hydrogel treatment significantly reduced the migratory and invasive capacities of RA fibroblast-like synoviocytes (RA-FLS) in vitro , through the decrease of phosphorylation of mTOR and its substrates, p70S6K1, thus inhibiting the mTOR pathway.
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PubMed
高影响因子
CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY
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2022
·
IF 2.004
C. Zhang,Y. Wan,X.H. Liang,M.H. Rong,G.T. Ma,L. Li,C.H. Hu,Chengying Tang
Au–Co nanoparticles (NPs) were prepared by water-phase chemical reduction method with metal precursor. The samples were coated with silica by Stöber method and characterized by ultraviolet and visible spectrophotometer (UV–vis), transmission electron microscopy (TEM) to obtain the absorption spectrum , size, composition distribution of the nanoparticles. The melting behaviors of the prepared Au 8 Co 2 NPs and Au 6 Co 4 NPs were examined by differential scanning calorimetry (DSC). It was observed by DSC measurements that two endothermic effects existed in range of 700.0 K–1350.0 K, corresponding to the melting temperatures of the nanoparticles and the bulk Au–Co alloys, respectively. The surface tension, surface segregation and surface energy of Au–Co NPs of particle size and temperature were calculated by the Butler's equation. On the basis of the obtained experimental results and the Gibbs free energy contributed by surface effects of pure elements and alloys at nanoscale, the nanophase diagrams of Au–Co system with various sizes were optimized. It was indicated that the calculated nanophase diagrams were in good agreement with the experimental results. The calculated eutectic temperatures decreased with the decrease of the size.
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高影响因子
JOURNAL OF MATERIALS RESEARCH
·
2022
·Vol. 37
·期 8
·1475-1485
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IF 2.909
Xu Jiaopeng,Chen Yingbo,Cao Ming,Wang Chuanfeng,Guo Pengfei
Solar steam generation (SSG) system greatly improves the efficiency of water evaporation through heat localization, which has broad application prospects at seawater desalination and wastewater treatment. In this paper, polyamide 6-graphene oxide (PA6-GO) membrane was fabricated by nonsolvent-induced phase separation of a solution with GO-modified PA6 in formic acid. Furthermore, the PA6-GO membrane was modified by vacuum filtration of self-assembly gold nanoparticles on its surface for solar stem generation. The composite membrane obtained a light absorption rate of nearly 99.8%. Under the irradiation of 1 kW m −2 , the evaporation rate of 1.1 kg m −2 h −1 was obtained and the evaporation efficiency also reached to 75.6%. The evaporation system has the characteristics of low cost, high stability, strong acid, and alkali corrosion resistance, suggesting great potentials in seawater desalination and sewage treatment. Graphical abstract
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CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Caiqin Wang,Cheng Qian,Ting Hu,Xiaofei Yang
It is significant to promote the efficiency of solar fuel cells via improving the utilization of solar in photoelectrocatalysis. In this work, hydrogenated TiO 2 (H-TiO 2 ) nanoparticles with Ti 3+ and/or oxygen vacancy (V O ) defects were obtained and have extended light absorption to visible light region. As a photochemical component, H-TiO 2 was further coupled with Au nanoparticles to assemble photoelectrocatalyst to apply in photo-assisted electrooxidation of ethanol. Due to the existence of defects in H-TiO 2 , the peak current density on Au/H-TiO 2 is improved by 5.4% with the assistance of light irradiation, and even up to 18.3% under simulated sunlight illumination, which is much higher than that on Au/W-TiO 2 (W-TiO 2 loaded Au) under the light irradiation. Meanwhile, it is demonstrated that the charge transfer is improved on Au/H-TiO 2 with Vo due to the existence of Vo, improving the separation of excited electrons and holes. Density function theory (DFT) based theoretical calculations illustrate that the energy barrier of reaction intermediates on Au-TiO 2 with Vo defects is lower than that without Vo, indicating that Au-TiO 2 with Vo is more energetically favorable. This work highlights the possibility of using defective semiconductor nanomaterials to combine photocatalysis and electrocatalysis in solar fuel cells and to further improve the efficiency of fuel cells under solar full spectrum.
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JOURNAL OF RAMAN SPECTROSCOPY
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2022
·Vol. 53
·期 8
·1386-1393
·
IF 2.727
Tong-Jiang Li,Bao-Ying Wen,Yue-Jiao Zhang,Lin Zhang,Jian-Feng Li
Organophosphorus (OPs) compounds have received enormous attention due to high neurotoxicity. However, the complex detection environment makes it very difficult to detect the OPs compounds at extremely low-concentration. Therefore, it is vital to develop a high sensitive analytical method for the detection of low-concentration OPs compounds at complex environment. Here, we proposed a novel surface-enhanced Raman scattering (SERS) substrate based on the core-shell structure Au@ZrO 2 for the detection of extremely low-concentration OPs compounds. By using above SERS substrate, we tested different kinds of OPs compounds and obtained excellent detection results. The detection limit of methyl parathion and triazophos can reach 0.01 mg/kg. Meanwhile, under the actual system (orange peel), the detection limit of the methyl parathion and triazophos also can reach 0.5 and 0.1 mg/kg, respectively. In addition, the above substrate is also very effective for the detection of dimethyl methylphosphonate (DMMP), a simulant for the chemical warfare agent (sarin), and the detection limit can reach 100 mg/kg. Besides, we also verified the reproducibility and stability of Au@ZrO 2 , which showed excellent properties. The relative standard deviation (RSD) of the SERS signal intensity for 20 tests was 6.38% and the enhancement ability of Au@ZrO 2 can remain stable within 30 days. These results show that the proposed Au@ZrO 2 SERS substrate has great potential in the detection of OPs compounds at extremely low-concentration in the complex detection environment.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Muhammad Humayun,Habib Ullah,Zhuo-Er Cheng,Asif Ali Tahir,Wei Luo,Chundong Wang
Highly efficient photocatalytic water reduction to evolve hydrogen can be achieved by the construction of Z-scheme systems that mimics natural photosynthesis. However, coupling appropriate semiconductors with suitable water reduction potential still remains challenging. Herein, we report a novel Z-scheme system, based on the Au decorated 5,10,15,20-tetrakis(4-trimethylammoniophenyl) porphyrin tetra(p-toluene sulfonate) functionalized iron-doped carbon nitride . We prepared carbon nitride by varying the amount of iron dopant and then functionalized with porphyrin to obtain heterostructure photocatalyst. Owing to the strong interfacial contact and proper band alignment, a Z-scheme system is fabricated. Finally, we deposited Au nanoparticles over the surface of the as-fabricated Z-scheme system to promote the surface redox properties via efficient charge carrier’s separation and transfer. The 3Au-3 P/30Fe-CN photocatalyst achieved excellent H 2 evolution activity by producing 3172.20 µmol h −1 g −1 under UV–visible irradiation. The calculated quantum efficiencies for 3Au-3 P/30Fe-CN photocatalyst at 365 and 420 nm irradiation wavelengths are 7.2% and 3.26%, respectively. The experimentally observed efficiency of our photocatalyst is supported by the density functional theory simulations in terms of the lowest work function and strong electrostatic interaction among the constituents of Z-scheme system.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Xiaoli Liu,Hongxia Zhang,Junping Ma,Jianbin Zheng
A novel non-enzymatic nitrite (NO 2 − ) electrochemical sensor was fabricated based on Au-poly(thionine) and tin oxide/graphene nanosheets (Au-PTH/SGN) nanocomposites . The morphology, composition and structure of the nanocomposites were characterized by Transmission electron microscopy, Energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy , X-ray diffraction and X-ray photoelectron spectroscopy. And the results indicated that homogeneous Au NPs with a size of approximate 80 nm and network nanostructure of PTH were attached on the surface of SGN nanomaterials. It had been also verified to satisfactory electrochemical results. The linear range of the proposed sensor was five orders of magnitude wide with the range of 0.2–127.7 (R 2 = 0.9991) and 127.7–2800 (R 2 = 0.9983) μmol L −1 , the detection limit was determined to be 0.06 μmol L −1 (S/N＝3) and the sensitivity were 61.92 and 43.19 μA (mmol L −1 ) −1 cm −2 , respectively. Compared with the similar type of NO 2 − sensors previously reported, the linear range was expanded by at least an order of magnitude and the detection limit was kept at the same level as the lowest. Furthermore, the constructed Au-PTH/SGN/GCE displayed fast response, excellent stability, reproducibility, and high anti-interference ability for NO 2 − detection. Moreover, the as-proposed electrode was successfully applied for detecting NO 2 − in tap water and sewage samples with recoveries ranging from 97.3% to 103.0%97.3%-103.0% and 98.7–102.6%, respectively. The present work is expected to provide a useful route and reference for designing novel high performance electrochemical sensors and broaden the applications of sensors .
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MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Zhenhu Guo,Jingsong Lu,Wensheng Xie,Xuezhong Li,Hong Wu,Lingyun Zhao
The strategic design for fabricating metal phenolic networks (MPNs) at different dimension brings potential possibilities to obtain MPNs-based system with controlled structure, biologically tunable physicochemical properties and high responsiveness behavior. Considering adequate Fe ions within Fe-based materials, self-supplied metal ions for polyphenol to form coating layer on the surface are served as a novel and facile strategies to obtain metal-based phenolic networks composites. Combing these, herein, a simple, green and fast strategy was performed to fabricate recyclable Fe@Fe 3+ -tannic acid-Au (Fe@MPNs-Au) system with high efficiency to catalyze the reduction of 4-nitrophenol. The obtained experimental results showed that the catalytic rate of Fe@MPNs-Au for 4-nitrophenol could be improved from 0.4398 min −1 to 1.5804 min −1 with the increase of Au loading. Additionally, the increased Fe 3+ -tannic acid MPNs layer thickness could also enhance the catalytic rate of Fe@MPNs-Au from 0.2226 min −1 to 2.085 min −1 . More importantly, the superior magnetic properties contributed by Fe core make it possible to be easily separated and collected by a magnet from the solution after multiple catalytic reduction reaction. Finally, we hope this strategy can provide a novel paradigm for fabricating metal-based phenolic networks system by in situ coordinating reaction between self-supplied Fe sources and phenolic molecules.
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高影响因子
MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Dan Liu,Haibin Tang,Yupeng Yuan,Chuhong Zhu
Surface-enhanced Raman scattering (SERS) spectroscopy can be used to realize sensitive rapid detection of molecules. Three-dimensional (3D) SERS substrates can provide more hotspots within the excitation laser beam when compared with the corresponding two-dimensional (2D) SERS substrates. Most of the methods for fabrication of 3D SERS substrates involve complex processes. Therefore, it is significant to develop a simple and effective method for fabrication of 3D SERS substrates. Here, a seed-assisted electrodeposition approach is developed for fabrication of a 3D SERS substrate composed of multilayer Au nanoparticles. Interestingly, it is demonstrated that a uniform film composed of multilayer Au nanoparticles that can serve as a 3D SERS substrate can be achieved directly by one-step electrodeposition on a conductive surface coated with monolayer Au seeds. It is found that a diffusion-controlled growth during electrodeposition narrows the nanoparticle size distribution and results monosized Au nanoparticles. The as-prepared multilayer Au nanoparticles-assembled film shows high SERS sensitivity and good spectral uniformity. For SERS detection of rhodamine 6G, a limit of detection as low as 3.4×10 −12 M has been achieved. Moreover, good spectral uniformity (relative standard deviation ∼7.8%) and high substrate-to-substrate reproducibility (relative standard deviation ∼8.6%) have also been demonstrated. The as-prepared multilayer Au nanoparticles-assembled film is used to detect organic pollutants such as dye molecule crystal violet (CV) and methylene blue (MB). Calibration curves with a linear correlation between the logarithmic SERS intensity and logarithmic concentration of CV and MB have been obtained. Limit of detections for CV and MB are 1.2×10 −8 M and 9.8×10 −10 M, respectively. Therefore, the fabricated 3D SERS substrate has good application prospects in sensitive detection of organic molecules.
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高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Dong Liu,Feiyang Hu,Yue Yan,Runping Ye,Xiaohan Chen,Bingying Han,Zhang-Hui Lu,Li Zhou,Gang Feng,Rongbin Zhang
CO oxidation is the primary approach for eliminating CO from incomplete combustion, and the catalytic performance is dependent on the structure of catalysts. Herein, to explore the structure promotion in the CO oxidation reaction, polymethyl methacrylate was synthesized as the hard template to fabricate the three-dimensional ordered microporous (3DOM) Au/CeO 2 and compared the catalytic performance with the Au/CeO 2 rod catalyst. The 3DOM Au/CeO 2 catalyst could realize complete CO oxidation at 90 °C while 110 °C for Au/CeO 2 rod catalyst. The 3DOM Au/CeO 2 catalyst also showed outstanding stability for 60 h reaction. The achieved high performance could be attributed to the pore structures and the better metal-support interaction that facilitates abundant oxygen vacancies . Additionally, the Au distribution and oxygen vacancies promoted by the macropores structures were discovered using a series of characterizations. This work highlights the promotion of oxygen vacancies and metal-support interaction by 3DOM structure in CO oxidation reaction.
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