Journal of the American Chemical Society
·
2024
·
IF 14.4
Hao Yu,Yujin Ji,Chenchen Li,Wenxiang Zhu,Yue Wang,Zhiwei Hu,Jing Zhou,Chih-Wen Pao,Wei-Hsiang Huang,Youyong Li,Xiaoqing Huang,Qi Shao
A strain engineering strategy is crucial for designing a high-performance catalyst. However, how to control the strain in metastable phase two-dimensional (2D) materials is technically challenging due to their nanoscale sizes. Here, we report that cerium dioxide (CeO2) is an ideal loading material for tuning the in-plane strain in 2D metastable 1T-phase IrO2 (1T-IrO2) via an in situ growth method. Surprisingly, 5% CeO2 loaded 1T-IrO2 with 8% compressive strain achieves an overpotential of 194 mV at 10 mA cm–2 in a three-electrode system. It also retained a high current density of 900 mA cm–2 at a cell voltage of 1.8 V for a 400 h stability test in the proton-exchange membrane device. More importantly, the Fourier transform infrared measurements and density functional theory calculation reveal that the CeO2 induced strained 1T-IrO2 directly undergo the *O–*O radical coupling mechanism for O2 generation, totally different from the traditional adsorbate evolution mechanism in pure 1T-IrO2. These findings illustrate the important role of strain engineering in paving up an optimal catalytic pathway in order to achieve robust electrochemical performance.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2024
·
IF 3.5
Zihao Hu,Xiaoying Zhou,Tiantian Zhang,Zuliang Wu,Jing Li,Wei Wang,Erhao Gao,Jiali Zhu,Shuiliang Yao
Aiming at the problem of the poor performance of an Mn-MOF-74-derived Mn3O4 catalyst in low-temperature carbon monoxide (CO) oxidation, copper (Cu) and cerium (Ce) elements were used to modify the Mn3O4 catalyst to improve its performance in low-temperature CO oxidation. According to the results of catalytic performance testing, the CO oxidation activity of the Cu0.3Mn2.7O4 catalyst was significantly improved compared with that of the pristine Mn3O4 catalyst, when a CO conversion rate of 90% was achieved at 118 °C. According to X-ray photoelectron spectroscopy and Brunauer–Emmett–Teller analyses, the (Mn2+ + Mn3+)/(Mn2+ + Mn3+ + Mn4+) ratio and the Oads/Ototal ratio increased after Cu doping, indicating promoted oxygen vacancy generation. In addition, the increased specific surface area was beneficial for the adsorption of reactant molecules and the exposure of active sites. According to H2-temperature-programmed reduction characterization, Cu doping significantly enhanced the performance of the Cu0.3Mn2.7O4 catalyst during low-temperature redox. Finally, these factors synergistically promoted the degradation of CO over the Cu0.3Mn2.7O4 catalyst. In addition, operando diffuse reflectance Fourier transform infrared spectroscopy results suggested the presence of more terminal-type oxygen, which is essential for the catalytic oxidation of CO on the surface of the Cu0.3Mn2.7O4 catalyst. Moreover, the Cu0.3Mn2.7O4 catalyst also showed excellent resistance to carbonate, and remarkable stability.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2024
·
IF 3.1
Peng Huan,Jiang Mengmeng,Ye Jinfeng,Wang Lei,Ding Shunmin,Cehn Chao
Oxygen vacancy in ceria is a crucial regulation factor for modifying materials. The reduced oxygen vacancy will undergo rapid recombination and deactivation due to the imbalance perturbation of active oxygen species, thereby restricting their larger-scale application. In this work, we proposed a strategy to stabilize oxygen vacancy in four black CeO x (Si) (0< x <2) by quartz sand doping reduction. The formation of a Ce-O v -Si (O v denoted as oxygen vacancy) interface, instrumental in constructing stable oxygen vacancies, is facilitated by rich hydroxyl groups. Characterizations of CeO x (Si) reveal that the heterogeneous hydrogen at the Ce-O-Si interface encourages the lattice distortion in ceria to obtain stable oxygen vacancies. Guided by the reusable feature, quartz sand doping reduction is a facile and feasible strategy to stabilize the oxygen vacancy of black CeO x for advanced materials on a large scale.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Yong Lu,Huixia Feng
Synergistic effect of rare earth salts conversion coating with phytic acid conversion coating was studied. Rare-earth salts were used as post-treatment to modify the phytic acid coated steel. The corrosion resistance properties of different coatings was investigated with electrochemical impedance spectroscopy in 3.5 wt.% NaCl solution. The corrosion resistance of phytic acid coated steel on steel was further enhanced with cerium nitrate post-treatment. The corrosion rate of phytic acid coated steel was seriously impaired by cerium nitrate post-treatment. But scanning electron microscopy (SEM) images indicated that there are also some micro-cracks on the coating surface when phytic acid coated steel was post-treated with cerium nitrate conversion bath. X-ray photoelectron spectroscopy (XPS) results demonstrated that the phytic acid could bind to the steel surface through the formation of -P-O-Fe and the cerium salts on the steel surface existed in the forms of both Ce 3+ and Ce 4+ .
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2018
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IF 2.732
J. Zhang,G.X. Zhang,G.M. Cai,Z.P. Jin
Due to the high sensitivity of the unshielded 5d orbit to the host environment, Ce 3+ has a wide-spread emission ranging from near ultraviolet to the red light region, making it a favorable choice for being UV-emitting phosphor activator and sensitizer of other co-doped lanthanide ions in luminescent materials. In present work, Ce 4+ →Ce 3+ self-reduction phenomenon in the layered phosphate MgIn 2 P 4 O 14 was observed. Noting that self-reduction ability is a valuable characteristic of new host materials, a new viewpoint underlying mechanism was put forward. Structure-, composition-, and temperature-dependence of photoluminescence of the new UV-emitting MgIn 2 P 4 O 14 : Ce x phosphors were investigated, with the relative mechanism discussed. Moreover, the sensitization of Dy 3+ by Ce 3+ was observed in Ce 3+ /Dy 3+ co-doped MgIn 2 P 4 O 14 phosphors. The excitation region of Dy 3+ in MgIn 2 P 4 O 14 : CeDy (220–460 nm) is markedly broadened compared to that of the Dy 3+ single-doped phosphor (270–460 nm) on account of the Ce 3+ →Dy 3+ energy transfer process . Present work shows that the MgIn 2 P 4 O 14 : CeDy phosphor can be promising phosphor using for fabrication of both light-emitting diodes (LEDs) and fluorescent lamps (FLs).
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Yunjia Hu,Tengchao Guo,Kangsen Peng,Shujuan Tan,Cheng Xu,Jie Deng
In this study, Ce 1−x Cu x O 2−x (x = 0, 0.01, 0.03, 0.05, 0.07) samples were prepared by hydrothermal method . The structure, microstructure, and elemental composition of the powders were characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, whereas the electrical conductivity , ultraviolet–visible absorption spectroscopy , and infrared emissivity at 3–5 μm were measured as well. Moreover, the effects of Cu 2+ doping concentration on the microstructure, morphology, bandgap, conductivity, and infrared emissivity of Cu-doped CeO 2 powders were systematically studied. The effects of Cu 2+ doping on infrared reflection and absorption in a 3–5 μm band and their mechanisms were explained based on electromagnetic theory, lattice vibration absorption, and free carrier absorption . Our result indicated that the emissivity of 1% Cu-doped powder reached the lowest emissivity of 0.200 at 800 °C. When the doping concentration was above 1%, the curve of infrared emissivity versus temperature exhibited a “U” shape, with the minimum point shifting towards the low-temperature region with the increase of Cu doping amount. This phenomenon was attributed to the different enhancement amplitude of reflectivity and absorbance of CeO 2 powder by Cu 2+ at different temperatures.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Analysis and Testing
·
2023
·Vol. 8
·期 2
·201-209
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IF 4.7
Yang Jing,Liu Hao,Huang Yan,Li Li,Liu Huajie,Ding Yaping
An “on–off–on” fluorescence sensor was designed for rapidly and consecutively detecting 4-nitrophenol and cerium(IV) without the use of any labeling materials. The yellow carbon dots were synthesized by a simple one-step hydrothermal approach, and various techniques were applied to investigate the morphology, structure, and optical properties of the carbon dots. Under the optimal experimental conditions, 4-nitrophenol rapidly quenched the fluorescence of carbon dots as a result of the inner filter effect (IFE). The fluorescence intensity of carbon dots was linear with the concentration of 4-nitrophenol (1–150 μmol/L) and the limit of detection was 0.32 μmol/L. The fluorescence was gradually recovered as the cerium(IV) concentration (0.5–100 μmol/L) increased in CDs/4-NP, and the limit of detection was 0.16 μmol/L. The sensor showed good selectivity and demonstrated high accuracy for the analysis of 4-nitrophenol and cerium(IV) in actual water samples.
研究领域:
分析化学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
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IF 7.489
Weihao Fan,Huaiyuan Wang,Chijia Wang,Zhanjian Liu,Kaka Li,Yanji Zhu
CeO 2 was used as the only oxidant for aniline polymerization, and polyaniline (PANI) was grown on CeO 2 surface to form CeO 2 @PANI nanocomposites. SEM and TEM showed that the CeO 2 @PANI composites were nanorods in a core-shell structure. XPS indicated that CeO 2 -core was reduced by aniline into Ce 3+ , which was then captured by the PANI-shell. Then the passive ability of CeO 2 @PANI coating on steels was explored. EIS showed that the impedance modulus of the CeO 2 @PANI coating exceeded 10 8 Ω·cm 2 after accelerated immersion. The SVET and XPS confirmed that PANI polarized the anodic reaction, Ce 3+ suppressed the cathodic reaction, and PO 4 3− formed complex precipitation. Some high-valent metal oxides can directly oxidize the aniline polymerization to form MO@PANI hybrid particles. The cations obtained by the metal oxide reduction can be captured by PANI and participate in passivation together with dopants. This study provides a new kind of nanocomposite fillers that can effectively passivate steel substrates within epoxy coatings for long-time protection.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GEOCHIMICA ET COSMOCHIMICA ACTA
·
2020
·
IF 4.659
Guanyu Deng,Tengfei Ma,Kazuya Tanaka,Toshihiko Ohnuki,Xinhong Qiu,Qianqian Yu
Ce anomaly is an important indicator for many geochemical processes. Although the role of strong ligand such as siderophore desferrioxamine B (DFOB) in facilitating negative Ce anomaly formation on Mn (hydr)oxide has been well studied, the effect of ubiquitous weak ligands such as polysaccharides on the mobility of Ce have not been considered. Here, we investigated the effects of polysaccharides with different molecular weights on Mn (hydr)oxide formation as well as the distribution coefficients of rare-earth elements (REEs) at the solid–liquid interface. In coprecipitation experiments, REEs distribution coefficients between Mn (hydr)oxide and the solution showed a negative Ce anomaly during coprecipitation of Mn in the presence of dextran with molecular weight of 5000 Dalton (Dextran 5 k). The molecular size of the saccharides affected the crystal growth of Mn (hydr)oxide. Mn (hydr)oxide was deposited on a matrix of polysaccharide molecules to form a metal–organic framework in the presence of dextran. The crystal size decreased with an increase in the length of the saccharide molecular chain . As a control test, when well crystallized δ-MnO 2 was used as an adsorbent, the distribution coefficients of the REEs showed a positive Ce anomaly in the presence of dextran 5 k. Based on the results, we suggest that the mechanism by which saccharides affect the sorption behavior of REEs on Mn (hydr)oxide is different from the reported mechanisms of strong metal-binding ligands such as DFOB. Saccharide-mediated electron transfer may occur between Mn (hydr)oxides and Ce(III), resulting in the formation of an organic-Ce(IV) complex in solution. Our results imply that ubiquitous weak ligands such as polysaccharides may significantly affect the mobility of Ce largely due to the association with Mn oxides, which are widespread natural electron acceptors.
研究领域:
地球化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Jin Chen,Mingzhu Jiang,Jing Chen,Wenjian Xu,Hongpeng Jia
Selective immobilization of single-atom Au on the specific facets of CeO 2 has been successfully performed by redox etching precipitation (REP), which makes it possible to clearly refine the interfacial effect of multiple-facet support on single atom . With systemic characterizations, it is found that single-atom Au is apt to lie on nonpolar facets of CeO 2 (111) and (110) rather than polar facet of CeO 2 (100). The modification of morphology-dependent properties is attributed to the different interaction between Au atom and each CeO 2 interface. Because of synergy between Au and CeO 2 , more oxygen vacancies and more active oxygen species are generated; meanwhile, the interfacial effect stabilizes the charged Au species which serves as active site. Therefore, the performance in catalytic oxidation of HCHO and CO on CeO 2 is facilitated by loading Au. Among them, CeO 2 rod-supported Au as an optimal catalyst exhibits a remarkable activity and stability. With in-situ characterization, the reaction mechanisms for HCHO and CO oxidation over Au/r-CeO 2 are studied. Meanwhile, it is proved that REP strategy is also valid to obviously promote catalytic performance whenever commercial CeO 2 is used or Au is replaced with Ag, so the improvement of recently applied catalyst with REP process is promising.
研究领域:
材料科学
·
环境催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2020
·Vol. 13
·期 24
·5768
·
IF 3.057
Zhuo Wang,Zhu Chen,Jie Zheng,Shufeng Zuo
In this study, three kinds of CeO2were synthesized, and supported PdOx(x = 0,1) catalysts were prepared for benzene catalytic combustion. The samples were characterized by XRD, N2adsorption/desorption, HRTEM, XPS and H2-TPR. The results show that three kinds of CeO2with different structures can be formed by different preparation methods. This is mainly reflected in the differences in pore structure, particle size and crystal plane. CeO2-DC obtained from directly calcined Ce(NO3)3·6H2O had the largest pore volume and pore diameter and smallest particle size. CeO2-DC was mainly exposed to the (200) plane. Combined with the results of the ability test, it could be concluded that when Pd2+and Pd0exist at the same time, the activity increases with an increase in the proportion of Pd2+. Meanwhile, the structure of CeO2affects the formation of oxygen vacancies, thereby affecting the adsorption and degradation of benzene. This article reveals that the particle size, crystal planes, oxygen vacancies and proportion of Pd2+have a great impact on the catalytic combustion of benzene and allow a more comprehensive understanding of the structure–activity relationship, which can guide us to design high-efficiency catalysts targeted to obtain suitable CeO2-based catalysts for the catalytic combustion of benzene.Keywords:cerium oxide;benzene;catalytic combustion;particle size;crystal surface
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2019
·
IF 2.961
Renping Cao,Yaqin Ran,Xinyan Lv,Longxiang Xu,Huijun Wan,Qianglin Hu,Ting Chen,Chunyan Cao
A series of single doped (Ce 3+ ) and co-doped (Ce 3+ and Mn 2+ ) Ca 8 ZnLa(PO 4 ) 7 (CZLP) phosphors are synthesized in air by using the solid-state reaction method. The crystal structure, morphology, and luminescence properties of the samples are investigated. The blue emission of CZLP:Ce 3+ phosphors is observed in the range of 325–450 nm when they are excited by 315 nm ultraviolet (UV) light, and the optimal Ce 3+ concentration is about 8 mol%. With excitation at 315 nm, a tunable color emission of CZLP:8%Ce 3+ , yMn 2+ phosphors from blue to red is displayed when Mn 2+ concentration is changed from 0 to 12 mol%, and the corresponding chromaticity coordinates are varied from (0.1635, 0.0118) to (0.5885, 0.2829). The spectral propertires and lifetimes confirm the energy transfer (ET) process from Ce 3+ to Mn 2+ ions in CZLP:8%Ce 3+ , Mn 2+ phosphor. The luminous mechanism and ET phenomenon are explained by using the Tanabe-Sugano diagram of Mn 2+ ion and the energy level diagrams of Ce 3+ and Mn 2+ ions. The experimental results are favorable for the improving and adjusting of luminescence properties of other phosphors.
研究领域:
材料科学
·
光学
✓ 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）