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Pei MJ, Shuai YK, Gao X, Chen JC, Liu Y, Yan W, Zhang J. Ni and Co Active Site Transition and Competition in Fluorine-Doped NiCo(OH) 2 LDH Electrocatalysts for Oxygen Evolution Reaction. Small 2024:e2400139. [PMID: 38497843 DOI: 10.1002/smll.202400139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 02/25/2024] [Indexed: 03/19/2024]
Abstract
The oxygen evolution reaction (OER) performance of NiCo LDH electrocatalysts can be improved through fluorine doping. The roles of Ni and Co active sites in such catalysts remain ambiguous and controversial. In addressing the issue, this study draws upon the molecular orbital theory and proposes the active center competitive mechanism between Ni and Co. The doped F-atoms can directly impact the valence state of metal atoms or exert an indirect influence through the dehydrogenation, thereby modulating the active center. As the F-atoms are progressively aggregate, the eg orbitals of Ni and Co transition from e2 g to e1 g , and subsequently to e0 g . The corresponding valence state elevates from +2 to +3, and then to +4, signifying an initial increase followed by a subsequent decrease in the electrocatalytic performance. Furthermore, a series of F-NiCo LDH catalysts are synthesized to verify the eg orbital occupancy analysis, and the catalytic OER overpotentials are 303, 243, 240, and 246 mV at the current density of 10 mA cm-2 , respectively, which coincides well with the theoretical prediction. This investigation not only provides novel mechanistic insights into the transition and competition of Ni and Co in F-NiCo LDH catalysts but also establishes a foundation for the design of high-performance catalysts.
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Affiliation(s)
- Mao-Jun Pei
- Institute for New Energy Materials and Engineering, College of Materials Science & Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Yan-Kang Shuai
- Institute for New Energy Materials and Engineering, College of Materials Science & Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Xiang Gao
- Institute for New Energy Materials and Engineering, College of Materials Science & Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Jia-Cheng Chen
- Institute for New Energy Materials and Engineering, College of Materials Science & Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Yao Liu
- Institute for New Energy Materials and Engineering, College of Materials Science & Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Wei Yan
- Institute for New Energy Materials and Engineering, College of Materials Science & Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Jiujun Zhang
- Institute for New Energy Materials and Engineering, College of Materials Science & Engineering, Fuzhou University, Fuzhou, Fujian, 350108, China
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2
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Zhao Y, Liu X, Chen J, Chen J, Chen J, Fan L, Yang H, Xi S, Shen L, Wang L. Promote electroreduction of CO 2 via catalyst valence state manipulation by surface-capping ligand. Proc Natl Acad Sci U S A 2023; 120:e2218040120. [PMID: 37216512 PMCID: PMC10235936 DOI: 10.1073/pnas.2218040120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 04/10/2023] [Indexed: 05/24/2023] Open
Abstract
Electrochemical CO2 reduction provides a potential means for synthesizing value-added chemicals over the near equilibrium potential regime, i.e., formate production on Pd-based catalysts. However, the activity of Pd catalysts has been largely plagued by the potential-depended deactivation pathways (e.g., [Formula: see text]-PdH to [Formula: see text]-PdH phase transition, CO poisoning), limiting the formate production to a narrow potential window of 0 V to -0.25 V vs. reversible hydrogen electrode (RHE). Herein, we discovered that the Pd surface capped with polyvinylpyrrolidone (PVP) ligand exhibits effective resistance to the potential-depended deactivations and can catalyze formate production at a much extended potential window (beyond -0.7 V vs. RHE) with significantly improved activity (~14-times enhancement at -0.4 V vs. RHE) compared to that of the pristine Pd surface. Combined results from physical and electrochemical characterizations, kinetic analysis, and first-principle simulations suggest that the PVP capping ligand can effectively stabilize the high-valence-state Pd species (Pdδ+) resulted from the catalyst synthesis and pretreatments, and these Pdδ+ species are responsible for the inhibited phase transition from [Formula: see text]-PdH to [Formula: see text]-PdH, and the suppression of CO and H2 formation. The present study confers a desired catalyst design principle, introducing positive charges into Pd-based electrocatalyst to enable efficient and stable CO2 to formate conversion.
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Affiliation(s)
- Yilin Zhao
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore117585, Singapore
| | - Xiaoqing Liu
- Department of Mechanical Engineering, National University of Singapore, Singapore117575, Singapore
| | - Jingyi Chen
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore117585, Singapore
| | - Junmei Chen
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore117585, Singapore
| | - Jiayi Chen
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore117585, Singapore
| | - Lei Fan
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore117585, Singapore
| | - Haozhou Yang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore117585, Singapore
| | - Shibo Xi
- Institute of Sustainability for Chemicals, Energy and Environment, A*STAR, Jurong Island, Singapore627833, Singapore
| | - Lei Shen
- Department of Mechanical Engineering, National University of Singapore, Singapore117575, Singapore
| | - Lei Wang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore117585, Singapore
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Li X, Chen M, Ye Y, Chen C, Li Z, Zhou Y, Chen J, Xie F, Jin Y, Wang N, Meng H. Electronic Structure Modulation of Nickel Sites by Cationic Heterostructures to Optimize Ethanol Electrooxidation Activity in Alkaline Solution. Small 2023; 19:e2207086. [PMID: 36650993 DOI: 10.1002/smll.202207086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/21/2022] [Indexed: 05/04/2023]
Abstract
It is a good idea for efficient production of hydrogen to use ethanol oxidation reaction (EOR) in place of oxygen evolution reaction (OER) in water electrolysis process. Ni-based non-precious electrocatalysts are widely used in the conversion of ethanol to acetic acid. Here, different selenide heterostructures (NiCoSe, NiFeSe, and NiCuSe) are prepared in which Ni sites are regulated by transition metal. The valence state of Ni is NiCuSe < NiCoSe < NiFeSe in the three heterojunctions. NiCoSe shows the optimized charge distribution of Ni sites and outstanding catalytic activity. The effective modulations lead to optimized d-band center and facilitates both adsorption and desorption of reaction intermediates, which improves the kinetics of EOR. The results of this work prove that with appropriate designed catalyst it is possible to replace kinetically slow OER with faster EOR in water electrolysis to produce hydrogen.
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Affiliation(s)
- Xiulan Li
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China
| | - Mingchuang Chen
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China
| | - Yanting Ye
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China
| | - Chengjie Chen
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China
| | - Zilong Li
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China
| | - Yifan Zhou
- Instrumental Analysis and Research Center, Sun Yat-sen University, Guangzhou, Guangdong, 510275, P. R. China
| | - Jian Chen
- Instrumental Analysis and Research Center, Sun Yat-sen University, Guangzhou, Guangdong, 510275, P. R. China
| | - Fangyan Xie
- Instrumental Analysis and Research Center, Sun Yat-sen University, Guangzhou, Guangdong, 510275, P. R. China
| | - Yanshuo Jin
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China
| | - Nan Wang
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China
| | - Hui Meng
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, P. R. China
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Ji Y, Gao X, Liu J, Li L, Chen K, Liao Z. Stoichiometry, Orbital Configuration, and Metal-to-Insulator Transition in Nd 0.8Sr 0.2NiO 3 Films. ACS Appl Mater Interfaces 2023; 15:11353-11359. [PMID: 36787345 DOI: 10.1021/acsami.2c22387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The discovery of superconductivity in the infinite-layer nickelate Nd0.8Sr0.2NiO2 has motivated tremendous efforts for its significance toward the understanding of high-temperature superconductivity. However, the synthesis of infinite-layer nickelates is instable and has become a hindrance to experimental progress. Optimizing the growth of precursor Nd0.8Sr0.2NiO3 by pulsed laser deposition is crucial for obtaining infinite-layer nickelates. By systematically investigating the growth of Nd0.8Sr0.2NiO3 with wide range of conditions, we found that the laser fluence plays a critical role in determining the stoichiometry, lattice structure, and electronic properties. A higher Ni deficiency and larger c-axis lattice constant appeared with the lower laser fluence. At 0.6 J/cm2, the Ni deficiency is as large as 25%. According to X-ray absorption spectra and X-ray linear dichroism, we further find that (i) there are no obvious changes of the Ni valence and (ii) the energy level of the dx2-y2 orbital gradually increases relative to the d3z2-r2 orbital with increasing Ni deficiency. What is more, the onset temperature and magnitude of the resistivity change at the metal-to-insulator transitions (MITs) also are found to decrease with increasing laser fluence during the growth.
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Affiliation(s)
- Yaoyao Ji
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Xiaofei Gao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Junhua Liu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Lin Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Kai Chen
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, Anhui, China
| | - Zhaoliang Liao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230026, Anhui, China
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5
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Liu W, Kawano K, Kamiko M, Kato Y, Okazaki Y, Yamada I, Yagi S. Effects of A-site Cations in Quadruple Perovskite Ruthenates on Oxygen Evolution Catalysis in Acidic Aqueous Solutions. Small 2022; 18:e2202439. [PMID: 35802899 DOI: 10.1002/smll.202202439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/09/2022] [Indexed: 06/15/2023]
Abstract
The quadruple perovskite ruthenate CaCu3 Ru4 O12 is more active and stable than the benchmark catalyst RuO2 in the oxygen evolution reaction (OER) in acidic aqueous solutions, where many oxide-based catalysts are dissolved. Studies on the crystal structures of quadruple perovskite ruthenates are rare, and the origin of OER activity or stability from a structural aspect has not been clarified in detail. This presents the need to study the effects of cations at the A site of quadruple perovskite ruthenates ACu3 Ru4 O12 (A = Ca, Sr, La, Nd, and Ce) on the OER catalytic activity and stability in acidic aqueous solutions. CaCu3 Ru4 O12 has the highest activity and stability among all quadruple perovskite samples. The type of cation at the A site changes the average Cu and Ru valence states, and the plot of OER activity versus the average Cu valence number shows a volcano-type relationship. In addition, stability increases with a decrease in Ru-O bond length. This research provides a good design principle for OER catalysts with high activity and stability in severely acidic aqueous solutions.
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Affiliation(s)
- Wei Liu
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo, 153-8505, Japan
| | - Kodai Kawano
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo, 153-8505, Japan
| | - Masao Kamiko
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo, 153-8505, Japan
| | - Yuta Kato
- Department of Materials Science, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Yuichi Okazaki
- Department of Materials Science, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Ikuya Yamada
- Department of Materials Science, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
- Department of Materials Science, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Shunsuke Yagi
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-Ku, Tokyo, 153-8505, Japan
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6
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Yokel RA, Wohlleben W, Keller JG, Hancock ML, Unrine JM, Butterfield DA, Grulke EA. The preparation temperature influences the physicochemical nature and activity of nanoceria. Beilstein J Nanotechnol 2021; 12:525-540. [PMID: 34136328 PMCID: PMC8182686 DOI: 10.3762/bjnano.12.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/23/2021] [Indexed: 06/12/2023]
Abstract
Cerium oxide nanoparticles, so-called nanoceria, are engineered nanomaterials prepared by many methods that result in products with varying physicochemical properties and applications. Those used industrially are often calcined, an example is NM-212. Other nanoceria have beneficial pharmaceutical properties and are often prepared by solvothermal synthesis. Solvothermally synthesized nanoceria dissolve in acidic environments, accelerated by carboxylic acids. NM-212 dissolution has been reported to be minimal. To gain insight into the role of high-temperature exposure on nanoceria dissolution, product susceptibility to carboxylic acid-accelerated dissolution, and its effect on biological and catalytic properties of nanoceria, the dissolution of NM-212, a solvothermally synthesized nanoceria material, and a calcined form of the solvothermally synthesized nanoceria material (ca. 40, 4, and 40 nm diameter, respectively) was investigated. Two dissolution methods were employed. Dissolution of NM-212 and the calcined nanoceria was much slower than that of the non-calcined form. The decreased solubility was attributed to an increased amount of surface Ce4+ species induced by the high temperature. Carboxylic acids doubled the very low dissolution rate of NM-212. Nanoceria dissolution releases Ce3+ ions, which, with phosphate, form insoluble cerium phosphate in vivo. The addition of immobilized phosphates did not accelerate nanoceria dissolution, suggesting that the Ce3+ ion release during nanoceria dissolution was phosphate-independent. Smaller particles resulting from partial nanoceria dissolution led to less cellular protein carbonyl formation, attributed to an increased amount of surface Ce3+ species. Surface reactivity was greater for the solvothermally synthesized nanoceria, which had more Ce3+ species at the surface. The results show that temperature treatment of nanoceria can produce significant differences in solubility and surface cerium valence, which affect the biological and catalytic properties of nanoceria.
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Affiliation(s)
- Robert A Yokel
- Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky, 40536-0596, USA
| | | | | | - Matthew L Hancock
- Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky, 40506-0046, USA
| | - Jason M Unrine
- Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky, 40546-0091, USA
| | | | - Eric A Grulke
- Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky, 40506-0046, USA
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7
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Nichols F, Lu JE, Mercado R, Dudschus R, Bridges F, Chen S. Platinum Oxide Nanoparticles for Electrochemical Hydrogen Evolution: Influence of Platinum Valence State. Chemistry 2020; 26:4136-4142. [PMID: 31659785 DOI: 10.1002/chem.201904559] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Indexed: 12/31/2022]
Abstract
Electrochemical hydrogen generation is a rising prospect for future renewable energy storage and conversion. Platinum remains a leading choice of catalyst, but because of its high cost and low natural abundance, it is critical to optimize its use. In the present study, platinum oxide nanoparticles of approximately 2 nm in diameter are deposited on carbon nitride (C3N4) nanosheets by thermal refluxing of C3N4 and PtCl2 or PtCl4 in water. These nanoparticles exhibit apparent electrocatalytic activity toward the hydrogen evolution reaction (HER) in acid. Interestingly, the HER activity increases with increasing Pt4+ concentration in the nanoparticles, and the optimized catalyst even outperforms commercial Pt/C, exhibiting an overpotential of only -7.7 mV to reach the current density of 10 mA cm-2 and a Tafel slope of -26.3 mV dec-1 . The results from this study suggest that the future design of platinum oxide catalysts should strive to maximize the Pt4+ sites and minimize the formation of the less active Pt2+ species.
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Affiliation(s)
- Forrest Nichols
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Jia En Lu
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Rene Mercado
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Ryan Dudschus
- Department of Physics, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Frank Bridges
- Department of Physics, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
| | - Shaowei Chen
- Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, California, 95064, USA
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8
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Liu Q, Liu J, Lu D, Li T, Zheng W. Dense Sm and Mn Co-Doped BaTiO₃ Ceramics with High Permittivity. Materials (Basel) 2019; 12:ma12040678. [PMID: 30823530 PMCID: PMC6416545 DOI: 10.3390/ma12040678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/18/2019] [Accepted: 02/20/2019] [Indexed: 11/16/2022]
Abstract
The structure, valence state, and dielectric properties of (Ba1−xSmx)(Ti0.99Mn0.01)O3 (BSTM) (x = 0.02‒0.07) ceramics prepared via a high temperature (1400 °C/12 h) solid state reaction were investigated. A homogeneous and dense microstructure was observed in all samples. With increasing Sm content, the crystal structure changed from tetragonal (x ≤ 0.06) to cubic (x = 0.07) and unit cell volume (V0) decreased continuously, which was mainly due to the substitution of Ba2+ ions by smaller Sm3+ ions in the perovskite lattice. Electron paramagnetic resonance investigation revealed that Mn ions were reduced from high valence to low valence under the role of Sm3+ donor, and only Mn2+ ions were observed at x = 0.07. The Curie temperature (Tc) moved to lower values, from 105.5 down to 20.4 °C, and the x = 0.07 sample satisfied Y5V specification with high permittivity (ε′RT > 13,000) and low loss (tan δ < 0.03).
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Affiliation(s)
- Qiaoli Liu
- Key Laboratory for Special Functional Materials in Jilin Provincial Universities, Jilin Institute of Chemical Technology, Jilin 132022, China.
- School of Materials Science and Engineering, Key Laboratory of Mobile Materials, MOE, and State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.
| | - Junwei Liu
- Key Laboratory for Special Functional Materials in Jilin Provincial Universities, Jilin Institute of Chemical Technology, Jilin 132022, China.
| | - Dayong Lu
- Key Laboratory for Special Functional Materials in Jilin Provincial Universities, Jilin Institute of Chemical Technology, Jilin 132022, China.
| | - Tingqu Li
- Key Laboratory for Special Functional Materials in Jilin Provincial Universities, Jilin Institute of Chemical Technology, Jilin 132022, China.
| | - Weitao Zheng
- School of Materials Science and Engineering, Key Laboratory of Mobile Materials, MOE, and State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China.
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9
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Nasir M, Islam R, Ahmed MA, Ayaz S, Kumar G, Kumar S, Prajapat CL, Roussel F, Biring S, Sen S. Cu 1-x Fe x O: hopping transport and ferromagnetism. R Soc Open Sci 2017; 4:170339. [PMID: 28989741 PMCID: PMC5627081 DOI: 10.1098/rsos.170339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
Single phase, sol-gel prepared Cu1-x Fe x O (0 ≤ x ≤ 0.125) powders are characterized in terms of structural, electronic and magnetic properties. Using dielectric and magnetic studies we investigate the coupling of electron and spin. The electrical conductivities and activation energies are studied with increasing Fe content. Modelling of experimental conductivity data emphasizes a single hopping mechanism for all samples except x = 0.125, which have two activation energies. Hole doping is confirmed by confirming a majority Fe3+ substitution of Cu2+ in CuO from X-ray photoelectron spectroscopy studies (XPS). Such a substitution results in stabilized ferromagnetism. Fe substitution introduces variation in coercivity as an intrinsic magnetic property in Fe-doped CuO, and not as a secondary impurity phase.
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Affiliation(s)
- Mohd. Nasir
- Department of Physics, Indian Institute of Technology Indore, Indore 453552, India
| | - Rakibul Islam
- Unite Materiaux et Transformations (UMET)–CNRS UMR 8207, University of Lille-Sciences and Technologies, UFR de Physique, Bat P5, 59655 Villeneuve d'Ascq, France
| | - Md. A Ahmed
- Department of Physics, University of Calcutta, Kolkata 700009, India
| | - Saniya Ayaz
- Department of Metallurgy Engineering and Material Science, Indian Institute of Technology Indore, Indore 453552, India
| | - Gautham Kumar
- Department of Electronic Engineering, Ming Chi University of Technology, New Taipei City, 8802, Taiwan, Republic of China
| | - Sunil Kumar
- Department of Metallurgy Engineering and Material Science, Indian Institute of Technology Indore, Indore 453552, India
| | - C. L. Prajapat
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Frederick Roussel
- Unite Materiaux et Transformations (UMET)–CNRS UMR 8207, University of Lille-Sciences and Technologies, UFR de Physique, Bat P5, 59655 Villeneuve d'Ascq, France
| | - Sajal Biring
- Department of Electronic Engineering, Ming Chi University of Technology, New Taipei City, 8802, Taiwan, Republic of China
| | - Somaditya Sen
- Department of Physics, Indian Institute of Technology Indore, Indore 453552, India
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10
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Swart HC. Surface Sensitive Techniques for Advanced Characterization of Luminescent Materials. Materials (Basel) 2017; 10:ma10080906. [PMID: 28777357 PMCID: PMC5578272 DOI: 10.3390/ma10080906] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/25/2017] [Accepted: 08/01/2017] [Indexed: 11/25/2022]
Abstract
The important role of surface sensitive characterization techniques such as Auger electron spectroscopy (AES), X-ray photo electron spectroscopy (XPS), time of flight scanning ion mass spectrometry (TOF-SIMS) and High resolution transmission electron microscopy (HRTEM) for the characterization of different phosphor materials is discussed in this short review by giving selective examples from previous obtained results. AES is used to monitor surface reactions during electron bombardment and also to determine the elemental composition of the surfaces of the materials, while XPS and TOF-SIMS are used for determining the surface chemical composition and valence state of the dopants. The role of XPS to determine the presence of defects in the phosphor matrix is also stated with the different examples. The role of HRTEM in combination with Energy dispersive spectroscopy (EDS) for nanoparticle characterization is also pointed out.
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Affiliation(s)
- Hendrik C Swart
- Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA93002, South Africa.
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11
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Peng H, Jian M, Deng H, Wang W, Huang Z, Huang K, Liu A, Chen W. Valence States Effect on Electrogenerated Chemiluminescence of Gold Nanocluster. ACS Appl Mater Interfaces 2017; 9:14929-14934. [PMID: 28398723 DOI: 10.1021/acsami.7b02446] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This work elucidated the valence states effect on the electrogenerated chemiluminescence (ECL) performance of gold nanocluster (AuNC). The N-acetyl-l-cysteine-AuNCs (NAC-AuNCs) and the electrochemical reduction method for reducing the AuNCs were first employed to this study. Results demonstrate that the electrochemical reduction degree of the AuNCs depended on the reduction potential, and the enhancement of the ECL signals was positively correlated with the reduction degree of AuNCs, which indicated that the valence state of Au plays a vital role in the ECL performance of AuNCs. Furthermore, the proposed method has been successfully extended to the chemical reduction technique and other nanoclusters. Therefore, an excellent AuNC-based ECL method with various advantages, such as simple preparation, lower toxicity, high sensitivity, and ΦECL, and excellent stability, has been proposed. This approach not only opens up a new avenue for designing and developing ECL device from other functional-metal based NCs, but also extends the huge potential application in the ECL sensing.
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Affiliation(s)
- Huaping Peng
- Department of Pharmaceutical Analysis, Fujian Medical University , Fuzhou 350004, China
- Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University , Fuzhou 350004, China
| | - Meili Jian
- Department of Pharmaceutical Analysis, Fujian Medical University , Fuzhou 350004, China
- Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University , Fuzhou 350004, China
| | - Haohua Deng
- Department of Pharmaceutical Analysis, Fujian Medical University , Fuzhou 350004, China
- Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University , Fuzhou 350004, China
| | - Wenjun Wang
- Department of Pharmaceutical Analysis, Fujian Medical University , Fuzhou 350004, China
- Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University , Fuzhou 350004, China
| | - Zhongnan Huang
- Department of Pharmaceutical Analysis, Fujian Medical University , Fuzhou 350004, China
- Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University , Fuzhou 350004, China
| | - Kaiyuan Huang
- Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University , Fuzhou 350004, China
| | - Ailin Liu
- Department of Pharmaceutical Analysis, Fujian Medical University , Fuzhou 350004, China
- Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University , Fuzhou 350004, China
| | - Wei Chen
- Department of Pharmaceutical Analysis, Fujian Medical University , Fuzhou 350004, China
- Higher Educational Key Laboratory for Nano Biomedical Technology of Fujian Province, Fujian Medical University , Fuzhou 350004, China
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Piet H, Badro J, Nabiei F, Dennenwaldt T, Shim SH, Cantoni M, Hébert C, Gillet P. Spin and valence dependence of iron partitioning in Earth's deep mantle. Proc Natl Acad Sci U S A 2016; 113:11127-30. [PMID: 27647917 DOI: 10.1073/pnas.1605290113] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We performed laser-heated diamond anvil cell experiments combined with state-of-the-art electron microanalysis (focused ion beam and aberration-corrected transmission electron microscopy) to study the distribution and valence of iron in Earth's lower mantle as a function of depth and composition. Our data reconcile the apparently discrepant existing dataset, by clarifying the effects of spin (high/low) and valence (ferrous/ferric) states on iron partitioning in the deep mantle. In aluminum-bearing compositions relevant to Earth's mantle, iron concentration in silicates drops above 70 GPa before increasing up to 110 GPa with a minimum at 85 GPa; it then dramatically drops in the postperovskite stability field above 116 GPa. This compositional variation should strengthen the lowermost mantle between 1,800 km depth and 2,000 km depth, and weaken it between 2,000 km depth and the D" layer. The succession of layers could dynamically decouple the mantle above 2,000 km from the lowermost mantle, and provide a rheological basis for the stabilization and nonentrainment of large low-shear-velocity provinces below that depth.
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Dunnick KM, Morris AM, Badding MA, Barger M, Stefaniak AB, Sabolsky EM, Leonard SS. Evaluation of the effect of valence state on cerium oxide nanoparticle toxicity following intratracheal instillation in rats. Nanotoxicology 2016; 10:992-1000. [PMID: 26898289 DOI: 10.3109/17435390.2016.1157220] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cerium (Ce) is becoming a popular metal for use in electrochemical applications. When in the form of cerium oxide (CeO2), Ce can exist in both 3 + and 4 + valence states, acting as an ideal catalyst. Previous in vitro and in vivo evidence have demonstrated that CeO2 has either anti- or pro-oxidant properties, possibly due to the ability of the nanoparticles to transition between valence states. Therefore, we chose to chemically modify the nanoparticles to shift the valence state toward 3+. During the hydrothermal synthesis process, 10 mol% gadolinium (Gd) and 20 mol% Gd, were substituted into the lattice of the CeO2 nanoparticles forming a perfect solid solution with various A-site valence states. These two Gd-doped CeO2 nanoparticles were compared to pure CeO2 nanoparticles. Preliminary characteristics indicated that doping results in minimal size and zeta potential changes but alters valence state. Following characterization, male Sprague-Dawley rats were exposed to 0.5 or 1.0 mg/kg nanoparticles via a single intratracheal instillation. Animals were sacrificed and bronchoalveolar lavage fluid and various tissues were collected to determine the effect of valence state and oxygen vacancies on toxicity 1-, 7-, or 84-day post-exposure. Results indicate that damage, as measured by elevations in lactate dehydrogenase, occurred within 1-day post-exposure and was sustained 7-day post-exposure, but subsided to control levels 84-day post-exposure. Furthermore, no inflammatory signaling or lipid peroxidation occurred following exposure with any of the nanoparticles. Our results implicate that valence state has a minimal effect on CeO2 nanoparticle toxicity in vivo.
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Affiliation(s)
- Katherine M Dunnick
- a HELD , National Institute for Occupational Safety and Health , Morgantown , WV , USA .,b Pharmaceutical and Pharmacological Sciences , West Virginia University , Morgantown , WV , USA
| | - Anna M Morris
- a HELD , National Institute for Occupational Safety and Health , Morgantown , WV , USA
| | - Melissa A Badding
- a HELD , National Institute for Occupational Safety and Health , Morgantown , WV , USA
| | - Mark Barger
- a HELD , National Institute for Occupational Safety and Health , Morgantown , WV , USA
| | - Aleksandr B Stefaniak
- c RHD , National Institute for Occupational Safety and Health , Morgantown , WV , USA , and
| | - Edward M Sabolsky
- d WVU Benjamin M. Statler College of Engineering and Mineral Resources , Morgantown , WV , USA
| | - Stephen S Leonard
- a HELD , National Institute for Occupational Safety and Health , Morgantown , WV , USA .,b Pharmaceutical and Pharmacological Sciences , West Virginia University , Morgantown , WV , USA
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Dunnick KM, Pillai R, Pisane KL, Stefaniak AB, Sabolsky EM, Leonard SS. The Effect of Cerium Oxide Nanoparticle Valence State on Reactive Oxygen Species and Toxicity. Biol Trace Elem Res 2015; 166:96-107. [PMID: 25778836 PMCID: PMC4469090 DOI: 10.1007/s12011-015-0297-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/03/2015] [Indexed: 11/01/2022]
Abstract
Cerium oxide (CeO2) nanoparticles, which are used in a variety of products including solar cells, gas sensors, and catalysts, are expected to increase in industrial use. This will subsequently lead to additional occupational exposures, making toxicology screenings crucial. Previous toxicology studies have presented conflicting results as to the extent of CeO2 toxicity, which is hypothesized to be due to the ability of Ce to exist in both a +3 and +4 valence state. Thus, to study whether valence state and oxygen vacancy concentration are important in CeO2 toxicity, CeO2 nanoparticles were doped with gadolinium to adjust the cation (Ce, Gd) and anion (O) defect states. The hypothesis that doping would increase toxicity and decrease antioxidant abilities as a result of increased oxygen vacancies and inhibition of +3 to +4 transition was tested. Differences in toxicity and reactivity based on valence state were determined in RLE-6TN rat alveolar epithelial and NR8383 rat alveolar macrophage cells using enhanced dark field microscopy, electron paramagnetic resonance (EPR), and annexin V/propidium iodide cell viability stain. Results from EPR indicated that as doping increased, antioxidant potential decreased. Alternatively, doping had no effect on toxicity at 24 h. The present results imply that as doping increases, thus subsequently increasing the Ce(3+)/Ce(4+) ratio, antioxidant potential decreases, suggesting that differences in reactivity of CeO2 are due to the ability of Ce to transition between the two valence states and the presence of increased oxygen vacancies, rather than dependent on a specific valence state.
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Affiliation(s)
- Katherine M Dunnick
- National Institute for Occupational Safety and Health, HELD, 1095 Willowdale Rd, Morgantown, WV, 26505, USA,
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