Scientific Reports
·
2016
·Vol. 6
·期 1
·1-7
·
IF 5.228
Yang Yushi,Mao Zhou,Huang Wenjie,Liu Lihua,Li Junli,Li Jialiang,Wu Qingzhi
CeO 2 nanoparticles (NPs) have been well demonstrated as an antioxidant in protecting against oxidative stress-induced cellular damages and a potential therapeutic agent for various diseases thanks to their redox enzyme-mimicking activities. The Ce 3+ /Ce 4+ ratio and oxygen vacancies on the surface have been considered as the major originations responsible for the redox enzyme-mimicking activities of CeO 2 NPs. Herein, CeO 2 nanostructures (nanocubes and nanorods) exposed different facets were synthesized via a facile hydrothermal method. The characterizations by X-ray photoelectron spectroscopy, Raman spectroscopy, and UV-Vis spectroscopy show that the Ce 3+ /Ce 4+ ratio and oxygen vacancy content on the surfaces of as-synthesized CeO 2 nanostructures are nearly at the same levels. Meanwhile, the enzymatic activity measurements indicate that the redox enzyme-mimicking activities of as-synthesized CeO 2 nanostructures are greatly dependent on their exposed facets. CeO 2 nanocubes with exposed {100} facets exhibit a higher peroxidase but lower superoxide dismutase activity than those of the CeO 2 nanorods with exposed {110} facets. Our results provide new insights into the redox enzyme-mimicking activities of CeO 2 nanostructures, as well as the design and synthesis of inorganic nanomaterials-based artificial enzymes.
研究领域:
生物材料学
·
纳米医学
·
催化酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Haiyan He,Ping Yang,Jia Li,Ruixia Shi,Ling Chen,Aiyu Zhang,Yuanna Zhu
CeO 2 nanostructures with various morphologies were prepared through controlling preparation conditions via a hydrothermal method without any surfactants and templates. Cerium acetate, cerium chloride and cerium nitrate were used as cerium precursors to investigate the influence of anions on the growth process of CeO 2 nanostructures. The morphology evolution of CeO 2 and Ce(OH) 3 nanostructures indicates that the anions play an important role for the growth kinetics of resulting samples. Cl − and Ac − ions promoted the formation of one dementional (1D) CeO 2 nanostructures such as nanowires, nanorods and nano hexagonal prisms, while the oxidizing anion NO 3 - facilitated the synthesis of CeO 2 nanocubes. The hydrothermal reaction temperature is another key to govern the morphologies of CeO 2 nanostructures. The formation process of the nanostructures was explored and the possible growth mechanism was discussed. The variety of CeO 2 nanostructures represented inequable catalytic performance for CO oxidation . Because of different surface areas and structures, CeO 2 nanowires revealed the best catalysis performance while that of the nanocubes is the worst.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Yingwei Li,Hao Li,Kexin Li,Ruirui Wang,Ruirui Zhang,Ruixia Liu
Nanostructured cerium-based catalytic materials have attracted much attention in the field of redox catalysis, due to the excellent active sites exposed on the nanocrystal surface, and herein, the oxygen vacancy (OV) and the crystal facet effect of typical model nanostructured ceria (Nano-CeO2) were focused and investigated for the catalytic aerobic cyclohexane oxidation. Specifically for the CeO2 nanocubes with a {100} facet, the CeO2 nanopolyhedrons with a dominant {111} facet, and the CeO2 nanorods with a dominant {110} facet, the catalytic roles of the OV and acid sites toward cyclohexane oxidation were systematically investigated. Surface oxygen vacancy (Sur-OV) and intrinsic oxygen vacancy (Int-OV), and particularly the active Sur-OV and active Int-OV performing catalytic activity under a working state specific for cyclohexane oxidation, were accurately recognized and distinguished. Furthermore, the activation ability of the OV sites for activating molecular oxygen into active oxygen species (OActive) was also revealed, and the acid site properties, which include the acidity and the types of acid sites, were probed and quantified. The Nano-CeO2 with an exposed {100} facet possesses the most active Sur-OV, determining the catalytic activity, and has the strongest activation ability, contributing to a high reaction activity under extremely inert conditions. The Nano-CeO2 with a {110} dominant facet with the most active Int-OV and abundant acid sites could accelerate further oxidation to adipic acid; the effect of the two key sites was described particularly by the α factor (= Total Acidity × Amount of Active Int-OV). Finally, the property–performance relationship toward cyclohexane oxidation was speculated based on the Nano-CeO2 catalytic system.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Richuan Rao,Hanwen Liang,Chunming Hu,Huaze Dong,Xiongzi Dong,Yongqiang Tang,Song Fang,Qiang Ling
Ag-CeO 2 nanoassemblys are prepared with a simple melamine-induced thermal decomposition method. Ag-CeO 2 nanoassemblys have a structure composed of Ag nanoparticles and CeO 2 nanoparticles. For Ag-CeO 2 nanoassemblys, Ag introduction can partially or completely activate lattice oxygen species of CeO 2 nanoparticles and however, the ease of Ag-CeO 2 interface oxygen activation is strongly influenced by their pyrolysis temperature. Ag-CeO 2 nanoassemblys prepared at 350 °C have only partial activation of CeO 2 surface oxygen. If the calcination temperature increases to 400 °C, Ag-CeO 2 nanoassemblys are fully activated to form more reducible interfacial lattice oxygen and to promote their low-temperature reductivity. Although excessive calcination temperature (500 °C) induces full activation of Ag-CeO 2 interface lattice oxygen, Ag-CeO 2 nanoassemblys will construct a new Ag-CeO 2 interface that is relative difficult to reduce, causing a less amount of reducible interface lattice oxygen provided at higher temperature. Ag-CeO 2 nanoassemblys are investigated to reveal the relationship of Ag-CeO 2 interfacial oxygen activation and CO catalytic oxidation performance. Ag-CeO 2 nanoassemblys with more interfacial lattice oxygen provided at lower temperature are found to have higher catalytic activity than that catalyst with the partially or excessively activated interfacial oxygen.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 47
·37585-37591
·
IF 3.84
Yunshi Liu,Hsueh-Shih Chen,Jia Li,Ping Yang
One dimensional (1D) CeO2 nanostructures have been successfully fabricated via a single nozzle electrospinning method and subsequent two-step calcination route by adjusting heating rates. The formation process of CeO2 nanotubes (NTs) and nanobelts (NBs) was investigated by observing the morphology evolution of fibers during calcination. Control of the heat-treatment procedure including solvent evaporation, the Kirkendall effect, polymer softening, and thermal decomposition of poly(vinylpyrrolidone) plays an important role in the morphologies of the samples. Well-dispersed and small Au nanoparticles (NPs) were deposited on 1D CeO2 nanostructures through a direct wet-chemical reaction or adding Au precursors during electrospinning. The results of the catalytic performance for CO oxidation suggest that CeO2 NTs display enhanced catalytic activities compared with CeO2 NBs. The loading of Au NPs significantly enhanced the catalytic properties of 1D CeO2 nanostructures. Because of the large surface areas, good crystallinity and the strong interfacial interactions between Au NPs and the CeO2 matrix, the 1% Au/CeO2 NTs exhibit superior catalytic activity with onset CO conversion at 65 °C and complete CO conversion at 142 °C.
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
危险品化学品经营许可证（带存储）