NEW JOURNAL OF CHEMISTRY
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2017
·Vol. 41
·期 22
·13472-13482
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IF 3.269
Mengqiu Huang,Yiwei Zhang,Yuming Zhou,Chao Zhang,Shuo Zhao,Jiasheng Fang,Yan Gao,Xiaoli Sheng
This work reports a novel type of sandwich-like hollow Au-based nanocatalyst, including a TiO2–ZrO2 shell, a hollow CeO2 core and Au nanoparticles of 2–5 nm. Uniform crystal ceria hollow nanostructures were synthesized using a simple one-step hydrothermal method without a template. Then binary TiO2–ZrO2 coated Au nanocatalysts were prepared via a facile bottom-up synthesis method. The structural features of the catalysts were characterized by several techniques, including SEM, TEM, EDX, FTIR, BET, XRD, UV-vis and XPS analyses. Using the reduction of 4-nitrophenol by NaBH4 as a model reaction, the TiO2–ZrO2/Au/CeO2 microspheres showed a superior catalytic activity and thermal stability compared with a pure TiO2 or ZrO2 layer. In addition, TiO2–ZrO2/Au/CeO2 microspheres calcined at 700 °C presented the highest thermal stability and reactivity. These comparative results were mainly attributed to the synergistic effect among the mixed oxide, hollow CeO2 core and Au NPs and the sandwich-like structure. As a consequence, this unique nanocatalyst will open a promising route for the fabrication of hollow binary-metal-oxide materials for future research and has great potential for other applications.
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
CHEMISTRY-A EUROPEAN JOURNAL
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2019
·Vol. 25
·期 23
·5904-5911
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IF 5.16
Guoqiang Liu,Zhiqing Cui,Miaomiao Han,Shengbo Zhang,Cuijiao Zhao,Chun Chen,Guozhong Wang,Haimin Zhang
Graphical Room at the active site : A room-temperature redox approach is used to prepare a composite core–shell-structured Au@CeO 2 electrocatalyst (see figure) composed of small gold nanoparticles (<10 nm) and rich oxygen vacancies in CeO 2 nanoparticles to synergistically boost the electrocatalytic activity toward the N 2 reduction reaction (NRR) to NH 3 . Electrosynthesis of NH 3 through the N 2 reduction reaction (NRR) under ambient conditions is regarded as promising technology to replace the industrial energy- and capital-intensive Haber–Bosch process. Herein, a room-temperature spontaneous redox approach to fabricate a core–shell-structured Au@CeO 2 composite, with Au nanoparticle sizes below about 10 nm and a loading amount of 3.6 wt %, is reported for the NRR. The results demonstrate that as-synthesized Au@CeO 2 possesses a surface area of 40.7 m 2 g −1 and a porous structure. As an electrocatalyst, it exhibits high NRR activity, with an NH 3 yield rate of 28.2 μg h −1 cm −2 (10.6 μg h −1 mg −1 cat. , 293.8 μg h −1 mg −1 Au ) and a faradaic efficiency of 9.50 % at −0.4 V versus a reversible hydrogen electrode in 0.01 m H 2 SO 4 electrolyte. The characterization results reveal the presence of rich oxygen vacancies in the CeO 2 nanoparticle shell of Au@CeO 2 ; these are favorable for N 2 adsorption and activation for the NRR. This has been further verified by theoretical calculations. The abundant oxygen vacancies in the CeO 2 nanoparticle shell, combined with the Au nanoparticle core of Au@CeO 2 , are electrocatalytically active sites for the NRR, and thus, synergistically enhance the conversion of N 2 into NH 3 .
研究领域:
化学
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2015
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IF 6.723
Xuehui Pang,Jianxiu Li,Yongbei Zhao,Dan Wu,Yong Zhang,Bin Du,Hongmin Ma,Qin Wei
A high-sensitivity electrochemiluminescence (ECL) sensor was conducted to detect carcinoembryonic antigen (CEA). Nanocomposites of graphene oxide/carboxylated multiwall carbon nanotubes/gold/cerium oxide nanoparticles (GO/MWCNTs-COOH/Au@CeO2) were used as antibody carriers and sensing platforms to modify on glassy carbon electrodes (GCE). CeO2 nanoparticles were first exploited as an ECL luminescent material and the possible ECL mechanism was proposed in this work. GO/MWCNTs-COOH was used as a loading matrix for CeO2 nanoparticles because of the superior conductivity and large specific surface area. Au nanoparticles were further deposited on this matrix to attach anti-CEA and enhance the sensitivity of immunosensor. The proposed sensing platform showed excellent cathodic ECL performance and sensitive response to CEA. The effects of experimental conditions on the ECL performance were investigated. The proposed immunosensor showed the broad linear range (0.05–100 ng/mL) and the low detection limit (LOD, 0.02 ng/mL, signal-to-noise ratio = 3) according to the selected experimental conditions. The excellent analysis performance for determination of CEA in the human serum samples simplied this immunosensor displayed high sensitivity and excellent repeatability. More importantly, this conducted immunosensor broadens the use scope of CeO2 nanoparticles.
研究领域:
生物医学工程
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分析化学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Weiyao Yang,Xiaojin Tang,Wenjing Li,Xin Luo,Chunyan Zhang,Chun Shen
Oxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA) is of great importance for the production of biopolymer. It is regarded as a representative of the heterogeneous process, in which the reactant in the gas phase and liquid phase interact with each other over the solid catalysts. Due to the low mass-transfer efficiency and co-existence of O 2 and organic compounds in the batch reactor, low catalytic efficiency and safety concerns hiders the commercial application. Herein, a micropacked-bed reactor was used to realize the efficient and ultrafast continuous-flow synthesis of FDCA. Au/CeO 2 was used as a catalyst and O 2 was used as a green oxidant. Owing to the enhanced gas − liquid mass transfer efficiency, an HMF conversion of 100% and an FDCA selectivity of 90 % were achieved within only 41 s, which represents a space–time-yield of 1–2 orders of magnitude higher than that of traditional reactors. By virtue of the minimized internal and external mass transfer resistances, kinetic parameters of the reaction were determined. The rate constants were more than one order of magnitude higher than those of other strategies. In addition, the oxidation of HMFCA to FFCA was determined to be the rate-controlling step. Overall, this work not only delineates an efficient strategy for synthesizing FDCA from HMF, but also opens a new avenue for enhancement of heterogeneous reactions suffering from limited mass transfer.
研究领域:
化学工程
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催化
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有机化学
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生物技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2022
·
IF 24.319
Jixiang Ji,Ruru Li,Hao Zhang,Yingnan Duan,Qian Liu,Haozhi Wang,Zhurui Shen
To date, the efficient photocatalytic conversion of CO 2 into high-value C2 products remains a great challenge. Herein, the Au-CeO 2 nanocomposite with Au-O-Ce sites at the micro-interface was developed to achieve a highly selective conversion of CO 2 into C 2 H 6 . This can be partially ascribed to the formation of key intermediates of COCO* was confirmed via in-situ Fourier transform infrared (FTIR) spectroscopy, indicating that the Au-CeO 2 micro-interface could prompt the multi-electron reduction of CO* before desorption, and enable the production of C2 species. Moreover, theoretical calculations suggested that Au-O-Ce sites at the micro-interface could reduce the energy barriers for the formation of COOH* and COCO*, facilitating the production of C 2 H 6 . Therefore, the Au-CeO 2 nanocomposite exhibited a C 2 H 6 production rate of 11.07 µmol g −1 h −1 and high electron selectivity of 93.1 % (product selectivity: 65.3 %), which is comparable with most state-of-the-art photocatalysts.
研究领域:
材料科学
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环境科学
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化学工程
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催化
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
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2024
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IF 4.9
Haolin Xiao,Chenghao Liu,Hanwen Ren,Shanshan Wei,Feijun Zhao,Liangli Cao,Zhencheng Chen
The advancement of Alzheimer’s disease (AD) is directly correlated to the phosphorylation damage of Tau protein (Tau-441), which is considered the most reliable indicator for early detection of AD. Nevertheless, the concentration of Tau-441 in human serum remains considerably low. To address this issue, a paper-based fluorescence immunosensor based on internal filter effect (IFE) was developed for the detection Tau-441. The microfluidic paper-based channel was prepared and modified with a gold layer to attach primary antibodies and increase the sensitivity of the sensor. All at once, Au@CeO 2 nanorods was employed as a fluorescence probe to hydrolyze p-nitrophenyl phosphate ( pNPP ), which generates hydrolyzed product p-nitrophenol (PNP) can reduce or quench the fluorescence intensity of N-doped graphene quantum dots (NGQDs). The immunosensor was designed to detect an increase in the amount of Tau-441 collected as the fluorescence intensity of NGQDs decreased. The developed sensor demonstrated satisfactory results in clinical serum samples, offering a promising concept for an immunoassay tagged with nanozymes for early detection of AD. Overall, this microfluidic paper-based fluorescent immunosensor has the potential to improve early diagnosis of AD.
研究领域:
生物医学工程
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医学诊断
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2023
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IF 5.5
Lu Ji,Fang Li,Conghui Che,Wei Xue,Qiusheng Yang,Xiaoshu Ding,Dongsheng Zhang,Xinqiang Zhao,Yanji Wang
In the reaction of dimethyl carbonate (DMC) and 2,4-diaminotoluene (TDA), Au/CeO 2 exhibits higher selectivity than CeO 2 for dimethyl toluene-2,4-dicarbamate (TDC). However, its catalytic activity drops after H 2 reduction (denoted as Au/CeO 2 -R). The characterization results illustrate that Au exists as a single atom with the primary species as Au δ+ in Au/CeO 2 , forming Ce x Au 1−x O 2 structure similar to solid solution. Whereas for Au/CeO 2 -R catalyst, Au mainly exists as Au 0 , forming the Au-O-Ce structure on CeO 2 surface. Significantly, the strong interaction between Au and CeO 2 increases Ce 3+ and oxygen vacancies content, as well as modulates their acidic property. However, the catalytic activity of Au/CeO 2 -R is found to be lower than Au/CeO 2 as the species formed by DMC dissociation on its surface are not easily desorbed. Other transition metals supported on CeO 2 are also prepared, wherein Pt/CeO 2 and Pd/CeO 2 exhibit good TDC selectivity. In the end, the electronegativity and catalytic activity of metals are correlated.
研究领域:
催化
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION
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2023
·
IF 2.7
Qi Xin,Li Wang,Haiyan Ruan,Ling Liu,Si Sun,Jing Zhang,Menglin Wu,Xiaoyu Mu,Hao Wang,Shaofang Zhang,Xiao-Dong Zhang
Redox-active nanozymes offer low-cost controlled synthesis, high stability, and tunable catalytic properties over natural enzymes, which have attracted wide attention in the field of disease diagnosis and treatment. However, the improvement of catalytic activity remains an important challenge for nanozymes. Herein, the Au/CeO 2 nanozymes is developed to achieve enhanced multiple enzyme-mimetic activity. The Au/CeO 2 nanozymes at 5% doping possess best peroxidase-like activity with threefold higher catalytic rate than CeO 2 . For catalase-mimic catalysis, the Au/CeO 2 nanozymes at 5% doping also exhibited a 1.5-fold enhanced reaction rate higher than pure CeO 2 . The superoxide dismutase (SOD)-like capacity of Au/CeO 2 nanozymes is proportional to Au content. The Au/CeO 2 nanozymes at 10% doping show optimal SOD-like capacity of 60.2 U mg −1 . In vitro experiments validate the regulation ability of intracellular oxidative stress and inflammation. Au/CeO 2 nanozymes can reduce lipopolysaccharide- or H 2 O 2 -induced oxidative damage by scavenging excess ROS in nerve cell. Therefore, Au/CeO 2 can be used as a promising antioxidant in disease treatment, and the study offers general guidelines for achieving enhanced biocatalytic property through atomic doping.
研究领域:
纳米技术
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生物催化
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疾病诊断与治疗
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2024
·
IF 8.3
Qi Xin,Shaofang Zhang,Si Sun,Nan Song,Yadong Zhe,Fangzhen Tian,Shu Zhang,Meili Guo,Xiao-Dong Zhang,Jianning Zhang,Hao Wang,Ruiping Zhang
Sepsis, a life-threatening condition caused by a dysregulated immune response to infection, leads to systemic inflammation, immune dysfunction, and multiorgan damage. Various oxidoreductases play a very important role in balancing oxidative stress and modulating the immune response, but they are stored inconveniently, environmentally unstable, and expensive. Herein, we develop multifunctional artificial enzymes, CeO2 and Au/CeO2 nanozymes, exhibiting five distinct enzyme-like activities, namely, superoxide dismutase, catalase, glutathione peroxidase, peroxidase, and oxidase. These artificial enzymes have been used for the biocatalytic treatment of sepsis via inhibiting inflammation and modulating immune responses. These nanozymes significantly reduce reactive oxygen species and proinflammatory cytokines, achieving multiorgan protection. Notably, CeO2 and Au/CeO2 nanozymes with enzyme-mimicking activities can be particularly effective in restoring immunosuppression and maintaining homeostasis. The redox nanozyme offers a promising dual-protective strategy against sepsis-induced inflammation and organ dysfunction, paving the way for biocatalytic-based immunotherapies for sepsis and related inflammatory diseases.
研究领域:
纳米技术
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免疫学
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炎症
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治疗学
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生物催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Acta Biomaterialia
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2023
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IF 9.7
Baofu Ma,Kun Zhang,Zhen Sun,Hui Pan,Kaiguang Yang,Bo Jiang,Baofeng Zhao,Zhen Liang,Yukui Zhang,Lihua Zhang
Relatively low catalytic activity and poor targeting limit the applications of nanoceria (CeO 2 ) nanozymes in the treatment of tumors. Here, we designed a unique pushpin-like Au/CeO 2 hybrid nanozyme with high catalytic activity by combining site-selective growth and steric restriction strategies. The enhanced enzyme activity was attributed to plasmon-induced hot electrons . Furthermore, the pushpin-like structure facilitated targeting molecule modification. The nanozyme exhibited superior antitumor effects both in vitro and in vivo due to its high catalytic activity and targeting effects. Importantly, its potential mechanism of anti-tumor therapy was studied by quantitative proteomics . The reactive oxygen species (ROS) generated by folic acid-PEG thiol-Au/CeO 2 (FA-Au/CeO 2 ) caused mitochondrial and proteasomal damage in tumor cells and further evoked a response to oxidative stress and innate immunity in vivo . This study provided a spatiotemporal approach to enhance the antitumor activity of nanozymes by structural design. The designed pushpin-like Au/CeO 2 could be utilized as a multifunctional nanoplatform for in vitro and in vivo plasmon-enhanced cancer therapy with active targeting effects. Moreover, this study systematically explored the anti-tumor mechanism of the nanozyme in both cell and mouse models, promoting its translation to the clinic. Statement of significance A strategy combining the principles of site-selective growth and steric restriction was developed to prepare a unique pushpin-like Au/CeO 2 hybrid nanozyme with high catalytic activity and low steric hindrance . The hybrid nanozyme showed superior antitumor activity at both the cellular and tissue levels. Furthermore, the antitumor mechanism was investigated in terms of the differential proteins and their pathways using quantitative proteomics, thus promoting the translation of nanozymes to the clinic.
研究领域:
纳米技术
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癌症治疗
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生物医学工程
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分子生物学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
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