SURFACE AND INTERFACE ANALYSIS
·
2025
·
IF 1.8
Huiling Jia,Sen Li,Menghao Liang,Jinxiu Wu,Xin Tan
The cationic surfactant hexadecyltrimethylammonium bromide (CTAB), Ce (NO 3 ) 3 ·6H 2 O, and ammonium nitrate/ethanol mixed solution were used as the mesoporous guiding template, the cerium source, and the selective solvent. PS@ m CeO 2 abrasives were synthesized using polystyrene (PS) as the core and mesoporous ceria ( m CeO 2 ) as the shell. The properties of PS@ m CeO 2 abrasives were examined by field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR), small-angle X-ray diffraction (XRD), HRTEM, X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption. The results showed that m CeO 2 was completely coated on the PS, with the PS core size of 240 nm and the m CeO 2 shell thickness of 15–20 nm. The content of O vacancies and Ce 3+ increased in the m CeO 2 shell. Irregular mesopores were formed in the shell. Young's modulus ( E ) and polishing property of CeO 2 abrasive, PS@CeO 2 composites, and PS@ m CeO 2 composites were measured by atomic force microscopy. The E of core@shell-structured composites significantly decreased. The PS@ m CeO 2 composites reduced mechanical damage and scratches and improved the material removal rate to 172 nm/min.
研究领域:
材料科学
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纳米技术
·
表面科学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 26
·38274-38287
·
IF 0
Yang Lei,Li Yucai,Li Xiaotong,Lu Haoqi,Wang Yuchao,Meng Hongyan,Ren Yongxiang,Lan Jun
With the wide application of nanomaterials, the concentration of nanomaterials in natural water continues to increase, which poses a severe threat to the water environment. However, the influence of organic matter and nanomaterials rich in natural water on the toxic effect of algae growth is still unclear. In this study, the effects of humic acid (HA) and nano-cerium oxide (nCeO 2 ) on the physiology and transcriptome of Chlorella sp. were analyzed, and the mechanism of the toxic effect of HA on Chlorella sp. under nCeO 2 stress was revealed. Under 20–200 mg/L nCeO 2 stress, the growth of Chlorella cells was inhibited and the highest inhibition rate reached 52% within 200 mg/L nCeO 2 . The Fv/Fm and ETRmax values of Chlorella sp. decreased from 0.490 and 24.45 (20 mg/L nCeO 2 ) to 0.488 and 23.4 (100 mg/L nCeO 2 ), respectively. Under the stimulation of nCeO 2 , the level of reactive oxygen species in algal cells was increased, accompanied by lipid peroxidation and membrane damage. However, the addition of HA at concentrations of 5–10 mg/L effectively alleviated the toxic effect of nCeO 2 on Chlorella sp. Transcriptome analysis showed that 10 mg/L HA could alleviate the cellular stress at 100 mg/L nCeO 2 on Chlorella sp. by regulating genes related to photosynthesis and metabolism pathways. Moreover, the downregulation of genes (e.g., Lhca1, Lhcb1, AOC3, and AOC2) indicated that HA reduced the level of oxidative stress in Chlorella sp. These findings offer novel insights of evaluating the ecotoxicity nCeO 2 and HA in natural water environment and their impact on Chlorella sp. Graphical abstract
研究领域:
环境科学
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毒理学
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植物学
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DOI
PubMed
Journal of Materials Research and Technology-JMR&T
·
2024
·
IF 6.2
Shufang Zhang,C. Cheng,Y.W. Ye,H. Chen
A series of W–Cu–Co-xCeO 2 composites were obtained through activation sintering method, and their microstructure and properties were systematically researched. As the amount of CeO 2 increased, the size of W particle in composites showed a decreasing trend as a whole. When the CeO 2 amount was 0∼0.8 wt%, the W particles in composites exhibited a large size and dense distribution. As the CeO 2 amount further increased, the size of W particle began to significantly decrease and the distribution area of Cu phase was uneven. The porosity of W–Cu–Co-xCeO 2 composites first decreased and then increased. The density, relative density, and hardness exhibited an opposite trend. When the CeO 2 amount was 0.8 wt%, these values reached their maximum values of 14.16 g/cm 3 , 98.66%, and 223 HV 3.0 , respectively. In addition, the friction coefficient (COF) and wear rate of W–Cu–Co-xCeO 2 composites first decreased and then increased, which reached the lowest values at CeO 2 of 0.8 wt%. At this time, the COF and wear rate were about 0.356 and 5.78 × 10 −6 mm 3 /Nm, respectively.
研究领域:
材料科学
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金属学
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DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 4
·781
·
IF 3.9
He Sun,Juping Zhang,Kongzhai Li,Hua Wang,Xing Zhu
HighlightsWhat are the main findings?A styrene yield of 91.4% was found for 10% k/CeO2at 500 °C and CO2-O2mixed atmosphere. The excellent catalytic performance of 10% k/CeO2is attributed to the alkali metal oxide modified cerium oxide and carbon dioxide induced oxygen vacancies to promote the dehydrogenation of ethylbenzene.What is the implication of the main finding?The proposed ODH strategy by using oxygen vacancies enriched catalysts offers an important insight into the efficient dehydrogenation of ethylbenzene at mild conditions.AbstractOxidative dehydrogenation (ODH) is an alternative for styrene (ST) production compared to the direct dehydrogenation process. However, ODH with O2or CO2suffers from either over-oxidation or endothermic property/low ethylbenzene conversion. Herein, we proposed an ODH process with a CO2-O2mixture atmosphere for the efficient conversion of ethylbenzene (EB) into styrene. A thermoneutral ODH is possible by the rationalizing of CO2/O2molar ratios from 0.65 to 0.66 in the temperature range of 300 to 650 °C. K modification is favorable for ethylbenzene dehydrogenation, and 10%K/CeO2achieved the highest ethylbenzene dehydrogenation activity due to the enhanced oxygen mobility and CO2adsorbability. The catalyst achieved 90.8% ethylbenzene conversion and 97.5% styrene selectivity under optimized conditions of CO2-4O2oxidation atmosphere, a temperature of 500 °C, and a space velocity of 5.0 h−1. It exhibited excellent catalytic and structural stability during a 50 h long-term test. CO2induces oxygen vacancies in ceria and promotes oxygen exchange between gaseous oxygen and ceria. The ethylbenzene dehydrogenation in CO2-O2follows a Mars-van Krevelen (MvK) reaction mechanism via Ce3+/Ce4+redox pairs. The proposed ODH strategy by using oxygen vacancies enriched catalysts offers an important insight into the efficient dehydrogenation of ethylbenzene at mild conditions.Keywords:ethylbenzene;oxidative dehydrogenation;ceria;CO2
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Jiayun Fu,Qianqian Zhang,Zhaoqiang Shi,Yemin Guo,Falan Li,Yanyan Zhang,Xia Sun
A novel electrochemical acetylcholinesterase (AChE) biosensor modified with cerium oxide-chitosan (CeO 2 -CS) and ordered mesoporous carbon-chitosan (OMC-CS) using a screen-printed carbon electrode (SPCE) was fabricated to detect organophosphorus pesticides (OPs). Compared with a common electrode, SPCEs do not need to be polished, can be conveniently carried, and are suitable for on-site detection. CeO 2 has good redox properties and a larger electron transfer rate. In addition, OMC has good electrical conductivity and a larger specific surface area, and chitosan (CS) has a considerable number of hydroxyl and amine groups in polymer chains, which have strong complexation ability. Herein, CeO 2 -CS and OMC-CS were modified in the SPCE layer by layer to improve the electrochemical response and increase the fixed amount of AChE. The results obtained with this biosensor revealed that its sensitivity was significantly improved. Taking into account the possible interaction between the test conditions, the experimental parameters were optimized using a quadratic orthogonal rotation combination design to achieve a high electrochemical signal. The properties of AChE/OMC-CS/CeO 2 -CS/SPCE were characterized by differential pulse voltammetry and cyclic voltammetry techniques. Under optimum conditions, the fabricated acetylcholinesterase biosensor showed great reproducibility and high stability. In addition, the as-prepared AChE biosensor was successfully utilized for analysis of OPs in vegetables.
研究领域:
生物化学
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分析化学
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DOI
高影响因子
JOURNAL OF CATALYSIS
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2016
·
IF 7.354
Shuang Liu,Xiaodong Wu,Wei Liu,Wenming Chen,Rui Ran,Min Li,Duan Weng
Three model ceria catalysts, which are monocrystalline CeO 2 nanocubes, polycrystalline CeO 2 nanoparticles, and polycrystalline CeO 2 spindles, were synthesized and analyzed with isothermal soot oxidation, H 2 -TPR, and Raman spectroscopy. The results suggest that the initial activity of the catalyst is determined by the number of catalyst–soot contact points rather than the catalyst surface area, while the catalyst stability is closely related to the concentration of surface oxygen vacancies . Excessive surface oxygen vacancies may inhibit the regeneration of highly active O 2 − and lead to catalyst deactivation during reaction. After impregnation with Ag, O − can be readily regenerated and transformed to O 2 − , resulting in a 10-fold increase in soot oxidation activity over Ag/CeO 2 . Among these catalysts, Ag supported on nanocubic CeO 2 exhibits good availability of O 2 − and therefore high catalytic activity and stability, and is thus considered a promising catalyst for application in gasoline particulate filters.
研究领域:
催化化学
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环境科学
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材料化学
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能源工程
·
大气污染控制
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2020
·
IF 7.1
Yu-Feng Sun,Jing-Jing Li,Feng Xie,Yan Wei,Meng Yang
Metal oxides nanomaterials are limited in electrochemical detection of heavy metal ions (HMIs) because of their poor conductivity and less active sites, which hinders electron transport and reduce the redox rate of HMIs, making it difficult to achieve sensitive and accurate detection of trace pollutions. Herein, Ru-loaded cerium dioxide nanocubes (Ru/CeO 2 ) with rich oxygen vacancies (OVs) was developed to construct electrochemical sensing interface. An unexpected sensitivity of up to 2169.8 μA μM −1 cm -2 was obtained with a detection limit of 0.019 μM in the detection of Hg(II). The predominantly exposed highly active (100) crystal facets and abundant OVs on the surface of CeO 2 nanocubes, as well as Ru nanoparticles with excellent metal activity, providing large amounts of reactive oxygen species and active sites, thereby enhancing the conductivity and adsorption capacity of the nanocomposites. Ultimately, the outstanding electrochemical signal was achieved by promoting the redox reaction of Hg(II). In addition, the proposed method shows the excellent stability and high anti-interference ability, and the accurate analysis of Hg(II) in real water samples was realized. This finding provides a good strategy for the development of nano-metal oxide with OVs for the reliable determination of trace heavy metal substance.
研究领域:
材料科学
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环境科学
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分析化学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2024
·
IF 4.2
He Zhang,Guo-Hua Zhang
In this study, using the ultra-fine molybdenum-27.5 wt% copper-(0–5) wt% tungsten-1.75 wt% nickel-0.75 wt% iron-0.5 wt% cerium dioxide composite powders as experimental materials, molybdenum‑copper‑tungsten‑nickel‑iron‑cerium dioxide blocks were obtained through low-temperature powder sintering. All alloy samples owned high relative densities (98.1 ± 0.05–98.9 ± 0.05%). Besides, the formations of molybdenum‑tungsten and γ-(copper, nickel, iron) solid solutions guaranteed the sample owned good comprehensive strength. Sintered block with the highest tension strength, compression strength, bending strength and hardness was prepared through introducing 2.5 wt% tungsten, which were 586 ± 4 MPa, 2928 ± 11 MPa, 1554 ± 5 MPa and 305 ± 3 HV respectively. However, the presences of iron, nickel and cerium dioxide affected the conductivities, and therefore, electric conductivities of the samples were 33.08 ± 0.02–33.47 ± 0.02 %IACS.
研究领域:
材料科学
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冶金工程
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DOI
高影响因子
MACROMOLECULAR BIOSCIENCE
·
2024
·Vol. 24
·期 8
·2400079
·
IF 4.4
Yingao Ma,Yanxia Zhang,Henigul Osman,Dong Zhang,Tianyou Zhou,Yunhai Zhang,Yingbo Wang
Trauma and tumor removal usually cause bone defects; in addition, the related postoperative infection also shall be carefully considered clinically. In this study, polylactic acid (PLLA) composite fibers containing Cerium oxide (CeO 2 ) are first prepared by electrospinning technology. Then, the PLLA/CeO 2 @PDA/Ag composite materials are successfully prepared by reducing silver ion (Ag + ) to nano-silver (AgNPs) coating in situ and binding AgNPs to the materials surface by mussel structure liked polydopamine (PDA). In the materials, Ag + can be slowly released in simulated body fluids. Based on the photothermal performance of AgNPs, the photothermal conversion efficiency of the materials is 21%, under NIR 808 nm illumination. The effective photothermal conversion can help materials fighting with E. coli and S. aureus in 3 h, with an antibacterial rate of 100%. Additionally, the sustained Ag + release contributes to the antibacterial in long term. Meanwhile, the materials can mimic the bio-behavior of superoxide dismutase and catalase in decreasing the singlet oxygen level and removing the excess reactive oxygen species. Furthermore, the materials are beneficial for cell proliferation and osteogenic differentiation in vitro. In this study, a promising bone-regenerated material with high photothermal conversion efficiency and antibacterial and anti-oxidation properties, is successfully constructed.
研究领域:
生物材料学
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医学工程
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组织工程
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产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2022
·Vol. 152
·期 11
·3437-3446
·
IF 2.936
Yue Yihang,Li Yong,Wang Tingting,Wang Shifeng,Han Lin,Du Chun
A Pd/CeO 2 -M with high methanol oxidation performance was prepared from metal–organic framework (MOF). The reaction results indicate that the Pd/CeO 2 -M could achieve 100% methanol oxidation at 200 °C over the traditional Pd/CeO 2 -C at 350 °C. The high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Raman show that the Pd was uniformly distributed over the CeO 2 that was rich in oxygen vacancies. The methanol temperature program surface reaction (MeOH-TPSR) demonstrates that the Pd/CeO 2 -M could effectively decompose methanol at a lower temperature with the assistance of oxygen vacancies compared with Pd/CeO 2 -C. Methanol oxidation was conducted with in-situ Raman, CO diffuse reflectance infrared Fourier transformed spectroscopy (CO-DRIFTS) and in-situ DRIFTS to elucidate the reaction mechanism and establish the structure–activity relationship. The oxygen vacancies have participated in the assistance of methanol oxidation, which was revealed via in-situ Raman. The CO-DRIFTS indicates that the chemisorbed CO was more in linear form, which demonstrates that the Pd particles were over CeO 2 -M with a smaller size. The in-situ DRIFTS experiments show the methanol could be further effectively oxidized to bidentate formate over Pd/CeO 2 -M with the assistance of oxygen vacancies. The Pd/CeO 2 -M catalysis and its enhancement mechanism studies provided a potential strategy in the VOC removal catalysis development. Graphical Abstract
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF RAMAN SPECTROSCOPY
·
2024
·
IF 2.4
Yi Hu,Jun Chen,Xinai Liu,Hang Zhong,Jingsong Xu,Jun Chen
To tackle the challenge of non-destructively analyzing complex oxide layers formed by atmospheric corrosion on active metals, we investigate the potential of inverse spatially offset Raman spectroscopy (inverse-SORS) to detect corrosion products and elucidate how the spectroscopic features of SORS vary. This study explores the utilization of inverse-SORS technology for longitudinal structural analysis of opaque CeO 2 /La 2 O 3 laminates, which serve as a proxy for corrosion products. Through a combination of experimental measurements and Monte Carlo simulation, it demonstrates the feasibility of inverse-SORS in non-destructively elucidating the layered structure of these laminates. With increasing the spatial offset of this technology, the Raman intensity ratio of La 2 O 3 -to-CeO 2 increases from 0.23 to 3.2 and then decreases to 0.27 for the CeO 2 /La 2 O 3 sample with a 34-μm-thick CeO 2 layer under 532-nm excitation, whereas the bottom La 2 O 3 layer is hardly detected when the thickness of the upper La 2 O 3 layer increases to 225 μm. The results reveal that a thinner CeO 2 layer facilitates the escape and detection of Raman signals originating from the bottom La 2 O 3 layer, leading to an enhanced La 2 O 3 -to-CeO 2 signal ratio and a reduced offset at the characteristic peak. The research also sheds light on the intricate interplay among multiple variables, such as spatial offset, laser wavelength, the corresponding absorption factor, the thickness of the oxide layer, and the compactness. These insights suggest that SORS is a valuable and non-destructive approach for dissecting the structures of highly turbid composites of metallic compounds and semi-quantitatively deducing their thickness.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2024
·
IF 6.3
Hang Shen,Zhihao Wu,Yifan Li,Xiangyi Du,Ruiyang Dou,Qiang Liu,Bowen Dai,Mingzhang Lin,Wei Huang,Hongbing Chen
With the widespread use of nuclear science and technology, slowing down the aging of polymers in a radiation environment has become a matter of great concern. In this work, cerium dioxide (CeO 2 ) and CeO 2 encapsulated with dopamine (PDA@CeO 2 ) were selected as special fillers to prepare the silicone rubber (SR) composites, and their radiation resistance were investigated by comparing the mechanical properties and thermal performance before and after irradiation. The interfacial bridge formed by PDA results in a greater elongation at break for PDA@CeO 2 /SR5.0 (770.0 ± 33.6 %) than for CeO 2 /SR (686.0 ± 15.0 %). After irradiation with γ-rays, the retention of elongation at break of both CeO 2 /SR0.1 and PDA@CeO 2 /SR0.1 were larger than SR. Furthermore, PDA@CeO 2 /SR0.1 showed an impressive retention of 90.5 ± 2.7 % of the tensile strength retention after exposure to an absorbed dose of 200 kGy. The disparity in crosslink density prior to and following irradiation indicated that both CeO 2 and PDA@CeO 2 were efficacious in reducing radiation crosslinking within the SR. An electron paramagnetic resonance spectrometer and an ultraviolet lamp (UV-EPR) were used to observe in real time the free radical scavenging ability of CeO 2 and PDA@CeO 2 inside the SR. These results indicated that CeO 2 and PDA@CeO 2 was expected to prevent further chain reactions in silicone rubber by scavenging free radicals generated in SR, thus improving the radiation resistance of SR.
研究领域:
材料科学
·
辐射生物学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）