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Thakur S, Mutreja V, Kaur R. Synergistic integration of ZrO 2-enriched reduced graphene oxide-based nanostructures for advanced photodegradation of tetracycline hydrochloride. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-33196-y. [PMID: 38632202 DOI: 10.1007/s11356-024-33196-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 03/29/2024] [Indexed: 04/19/2024]
Abstract
The escalating demand for the antibiotic drug tetracycline hydrochloride (TCH) contributes to an increased release of its residues into land and water bodies, which poses risks to both aquatic life and human health. Therefore, it is precedence to effectively degrade TCH residues to protect environment from their long-term impacts. In this aspect, the present study entails the synthesis of zirconia (ZrO2) nanostructures and focuses on the enhancement in the catalytic performance of ZrO2 nanostructures by employing reduced graphene oxide (RGO) as a solid support to synthesize ZrO2-enriched RGO-based photocatalysts (ZrO2-RGO) for the degradation of TCH. The study delves into comprehensive spectroscopic and microscopic investigations and their photodegradation assessments. Powder XRD and HR-TEM studies depicted the phase crystallinity and also displayed uniform distribution of ZrO2 nanostructures with spherical morphology within ZrO2-RGO. This corresponds to high surface-to-volume ratios, providing a substantial number of active sites for light absorption and generation of e--h+ pairs. Moreover, the heterojunctions created between RGO and ZrO2 nanostructures promoted the interspecies electron transfer which prolonged the recombination time of e- and h+ than pure ZrO2 nanostructures, accounted for enhanced degradation of TCH using ZrO2-RGO. The photocatalytic activity of as-synthesized materials were examined under visible and UV light irradiation. The degradation efficiency of ~ 73.82% was achieved using ZrO2-RGO-based photocatalyst with rate constant k = 0.007023 min-1 under visible-light illumination. Moreover, under UV-light, the degradation rate was explicated to be k = 0.01017 min-1 with ~ 85.56% degradation of TCH antibiotics within 180 mins. Hence, the synthesized ZrO2-enriched RGO-based photocatalysts represents a promising potential for the effective degradation of pharmaceutical compounds, particularly TCH under visible and UV-light irradiation.
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Affiliation(s)
- Sakshi Thakur
- Department of Chemistry, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India
| | - Vishal Mutreja
- Department of Chemistry, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India
| | - Ranjeet Kaur
- University Centre for Research & Development (UCRD), Department of Chemistry, Chandigarh University, Gharuan, Mohali, Punjab, 140413, India.
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2
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Pei C, Chen S, Fu D, Zhao ZJ, Gong J. Structured Catalysts and Catalytic Processes: Transport and Reaction Perspectives. Chem Rev 2024; 124:2955-3012. [PMID: 38478971 DOI: 10.1021/acs.chemrev.3c00081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
The structure of catalysts determines the performance of catalytic processes. Intrinsically, the electronic and geometric structures influence the interaction between active species and the surface of the catalyst, which subsequently regulates the adsorption, reaction, and desorption behaviors. In recent decades, the development of catalysts with complex structures, including bulk, interfacial, encapsulated, and atomically dispersed structures, can potentially affect the electronic and geometric structures of catalysts and lead to further control of the transport and reaction of molecules. This review describes comprehensive understandings on the influence of electronic and geometric properties and complex catalyst structures on the performance of relevant heterogeneous catalytic processes, especially for the transport and reaction over structured catalysts for the conversions of light alkanes and small molecules. The recent research progress of the electronic and geometric properties over the active sites, specifically for theoretical descriptors developed in the recent decades, is discussed at the atomic level. The designs and properties of catalysts with specific structures are summarized. The transport phenomena and reactions over structured catalysts for the conversions of light alkanes and small molecules are analyzed. At the end of this review, we present our perspectives on the challenges for the further development of structured catalysts and heterogeneous catalytic processes.
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Affiliation(s)
- Chunlei Pei
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Sai Chen
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Donglong Fu
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Zhi-Jian Zhao
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
| | - Jinlong Gong
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
- National Industry-Education Platform of Energy Storage, Tianjin University, 135 Yaguan Road, Tianjin 300350, China
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3
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Amairia C, Fessi S, Mhamdi M, Ghorbel A, Llorca J. Influence of the drying mode of support on the properties of Pd/Al 2O 3-ZrO 2 materials used for methane combustion. Sci Rep 2023; 13:20298. [PMID: 37985717 PMCID: PMC10662462 DOI: 10.1038/s41598-023-47630-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 11/16/2023] [Indexed: 11/22/2023] Open
Abstract
This work constitutes a new trial to enhance the properties of palladium supported on alumina modified with zirconium used as catalysts for methane combustion. The effect of the support drying mode is studied. For this aim, Al2O3-ZrO2 binary oxides with zirconium loading of 2 and 5% in weight were prepared using sol-gel process then dried under ordinary or supercritical conditions. Palladium with a loading of 0.5% was deposited on the support by wet impregnation. Several techniques have been used to investigate differences between the two types of the derived catalysts.
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Affiliation(s)
- C Amairia
- Laboratoire de Chimie des Matériaux et Catalyse, Département de Chimie, Faculté des Sciences de Tunis, Université Tunis-El Manar, Campus Universitaire, 2092, Tunis, Tunisia.
- Chemistry Department, College of Science, Al Baha University, Al Bahah, 65779, Saudi Arabia.
| | - S Fessi
- Laboratoire de Chimie des Matériaux et Catalyse, Département de Chimie, Faculté des Sciences de Tunis, Université Tunis-El Manar, Campus Universitaire, 2092, Tunis, Tunisia
| | - M Mhamdi
- Laboratory for the Application of Materials to the Environment, Water and Energy LAMEEE, Faculty of Sciences Gafsa, University of Gafsa, 2112, Gafsa, Tunisia
- Chemistry Department, College of Science and Arts Al Makhwah, Al Baha University, Al Bahah, Saudi Arabia
| | - A Ghorbel
- Laboratoire de Chimie des Matériaux et Catalyse, Département de Chimie, Faculté des Sciences de Tunis, Université Tunis-El Manar, Campus Universitaire, 2092, Tunis, Tunisia
| | - J Llorca
- Universitat Politècnica de Catalunya, Barcelone, Spain
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Luo YT, Zhou Z, Wu CY, Chiu LC, Juang JY. Analysis of Hazy Ga- and Zr-Co-Doped Zinc Oxide Films Prepared with Atmospheric Pressure Plasma Jet Systems. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2691. [PMID: 37836332 PMCID: PMC10574760 DOI: 10.3390/nano13192691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023]
Abstract
Co-doped ZnO thin films have attracted much attention in the field of transparent conductive oxides (TCOs) in solar cells, displays, and other transparent electronics. Unlike conventional single-doped ZnO, co-doped ZnO utilizes two different dopant elements, offering enhanced electrical properties and more controllable optical properties, including transmittance and haze; however, most previous studies focused on the electrical properties, with less attention paid to obtaining high haze using co-doping. Here, we prepare high-haze Ga- and Zr-co-doped ZnO (GZO:Zr or ZGZO) using atmospheric pressure plasma jet (APPJ) systems. We conduct a detailed analysis to examine the interplay between Zr concentrations and film properties. UV-Vis spectroscopy shows a remarkable haze factor increase of 7.19% to 34.8% (+384%) for the films prepared with 2 at% Zr and 8 at% Ga precursor concentrations. EDS analysis reveals Zr accumulation on larger and smaller particles, while SIMS links particle abundance to impurity uptake and altered electrical properties. XPS identifies Zr mainly as ZrO2 because of lattice stress from Zr doping, forming clusters at lattice boundaries and corroborating the SEM findings. Our work presents a new way to fabricate Ga- and Zr-co-doped ZnO for applications that require low electrical resistivity, high visible transparency, and high haze.
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Affiliation(s)
- Yu-Tang Luo
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan; (Y.-T.L.); (Z.Z.); (C.-Y.W.); (L.-C.C.)
| | - Zhehan Zhou
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan; (Y.-T.L.); (Z.Z.); (C.-Y.W.); (L.-C.C.)
| | - Cheng-Yang Wu
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan; (Y.-T.L.); (Z.Z.); (C.-Y.W.); (L.-C.C.)
| | - Li-Ching Chiu
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan; (Y.-T.L.); (Z.Z.); (C.-Y.W.); (L.-C.C.)
| | - Jia-Yang Juang
- Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan; (Y.-T.L.); (Z.Z.); (C.-Y.W.); (L.-C.C.)
- Program in Nanoengineering and Nanoscience, Graduate School of Advanced Technology, National Taiwan University, Taipei 10617, Taiwan
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Halawa MI, Saqib M, Lei W, Su L, Zhang X. Zirconium-Directed Supramolecular Self-Assembly of Coenzyme A@GNCs with Enhanced Phosphorescence for Developing Ultrasensitive Tracer Probe of Dipicolinic Acid, a Biomarker of Bacterial Spores. Anal Chem 2023; 95:11164-11171. [PMID: 37437237 DOI: 10.1021/acs.analchem.3c02209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Luminescent gold nanoclusters (GNCs) are a class of attractive quantum-sized nanomaterials bridging the gap between organogold complexes and gold nanocrystals. They typically have a core-shell structure consisting of a Au(I)-organoligand shell-encapsulated few-atom Au(0) core. Their luminescent properties are greatly affected by their Au(I)-organoligand shell, which also supports the aggregation-induced emission (AIE) effect. However, so far, the luminescent Au nanoclusters encapsulated with the organoligands containing phosphoryl moiety have rarely been reported, not to mention their AIE. In this study, coenzyme A (CoA), an adenosine diphosphate (ADP) analogue that is composed of a bulky 5-phosphoribonucleotide adenosine moiety connected to a long branch of vitamin B5 (pantetheine) via a diphosphate ester linkage and ubiquitous in all living organisms, has been used to synthesize phosphorescent GNCs for the first time. Interestingly, the synthesized phosphorescent CoA@GNCs could be further induced to generate AIE via the PO32- and Zr4+ interactions, and the observed AIE was found to be highly specific to Zr4+ ions. In addition, the enhanced phosphorescent emission could be quickly turned down by dipicolinic acid (DPA), a universal and specific component and also a biomarker of bacterial spores. Therefore, a Zr4+-CoA@GNCs-based DPA biosensor for quick, facile, and highly sensitive detection of possible spore contamination has been developed, showing a linear concentration range from 0.5 to 20 μM with a limit of detection of 10 nM. This study has demonstrated a promising future for various organic molecules containing phosphoryl moiety for the preparation of AIE-active metal nanoclusters.
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Affiliation(s)
- Mohamed Ibrahim Halawa
- School of Biomedical Engineering, International Health Science Innovation Center, Shenzhen Key Laboratory for Nano-Biosensing Technology, Marshall Laboratory of Biomedical Engineering, Medical School, Shenzhen University, Shenzhen 518055, P. R. China
- Guangdong Laboratory of Artificial Intelligence & Digital Economy (SZ), Shenzhen University, Shenzhen 518060, China
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
- Department of Chemistry, College of Science, United Arab Emirates University, Al Ain 15551, United Arab Emirates
| | - Muhammad Saqib
- Institute of Chemistry, Khwaja Fareed University of Engineering & Information Technology, Rahim Yar Khan 64200, Pakistan
| | - Weihao Lei
- School of Biomedical Engineering, International Health Science Innovation Center, Shenzhen Key Laboratory for Nano-Biosensing Technology, Marshall Laboratory of Biomedical Engineering, Medical School, Shenzhen University, Shenzhen 518055, P. R. China
| | - Lei Su
- School of Biomedical Engineering, International Health Science Innovation Center, Shenzhen Key Laboratory for Nano-Biosensing Technology, Marshall Laboratory of Biomedical Engineering, Medical School, Shenzhen University, Shenzhen 518055, P. R. China
| | - Xueji Zhang
- School of Biomedical Engineering, International Health Science Innovation Center, Shenzhen Key Laboratory for Nano-Biosensing Technology, Marshall Laboratory of Biomedical Engineering, Medical School, Shenzhen University, Shenzhen 518055, P. R. China
- Guangdong Laboratory of Artificial Intelligence & Digital Economy (SZ), Shenzhen University, Shenzhen 518060, China
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Yang S, Lee JH, Shin TJ, Park S. Insights of Peculiar Green-Yellow Emission Occurrence in Ce 3+-Doped Barium Yttrium Orthogermanate Phosphors. Inorg Chem 2023. [PMID: 37399075 DOI: 10.1021/acs.inorgchem.3c01121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
The Ba8.8Ce0.1Na0.1Y2Ge6O24 orthogermanate phosphor, prepared by LiCl flux assistance under a reducing atmosphere, exhibited a mysterious green-yellow emission at 298 K. A blue-emitting orthogermanate phosphor was expected to be achieved through the lower d-band of Ce3+ ions in the host structure owing to their optical structure geometry. Oxygen vacancies were observed in the phosphors through investigating bond-length fluxations, the oxygen 1s profile, and the Ge2+/Ge4+ oxidation state, using synchrotron X-ray diffraction refinement, X-ray photoelectron spectroscopy, and Ge K-edge X-ray absorption near-edge structure spectra, respectively. The Ba-M4,5 edge shift, bonding limitation, and distortion index discovery reveal the oxygen-coordinating environment variation around the Ba2+(Ce3+) ions in the phosphors. The green-yellow emission results from the active 6-coordinated antiprism oxygen geometry around the Ce3+ ions in the phosphors.
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Affiliation(s)
- Sungjun Yang
- Department of Environmental Energy & Chemistry, College of Engineering, Silla University, Busan 46958, Republic of Korea
| | - Jong Hoon Lee
- UNIST Central Research Facilities (UCRF), Ulsan National Institute of Science and Engineering (UNIST), Ulsan 44919, Republic of Korea
| | - Tae Joo Shin
- Graduate School of Semiconductor Materials and Devices Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Sangmoon Park
- Department of Environmental Energy & Chemistry, College of Engineering, Silla University, Busan 46958, Republic of Korea
- Department of Fire Protection and Safety Management, College of Health and Welfare, Silla University, Busan 46958, Republic of Korea
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7
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Strijevskaya A, Yamaguchi A, Shoji S, Ueda S, Hashimoto A, Wen Y, Wardhana AC, Lee JE, Liu M, Abe H, Miyauchi M. Nanophase-Separated Copper-Zirconia Composites for Bifunctional Electrochemical CO 2 Conversion to Formic Acid. ACS APPLIED MATERIALS & INTERFACES 2023; 15:23299-23305. [PMID: 37140359 DOI: 10.1021/acsami.3c02874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A copper-zirconia composite having an evenly distributed lamellar texture, Cu#ZrO2, was synthesized by promoting nanophase separation of the Cu51Zr14 alloy precursor in a mixture of carbon monoxide (CO) and oxygen (O2). High-resolution electron microscopy revealed that the material consists of interchangeable Cu and t-ZrO2 phases with an average thickness of 5 nm. Cu#ZrO2 exhibited enhanced selectivity toward the generation of formic acid (HCOOH) by electrochemical reduction of carbon dioxide (CO2) in aqueous media at a Faradaic efficiency of 83.5% at -0.9 V versus the reversible hydrogen electrode. In situ Raman spectroscopy has revealed that a bifunctional interplay between the Zr4+ sites and the Cu boundary leads to amended reaction selectivity along with a large number of catalytic sites.
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Affiliation(s)
- Anna Strijevskaya
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Meguro, Tokyo, 152-8552, Japan
- Uzbek-Japan Innovation Center of Youth, Tashkent 100095, Uzbekistan
| | - Akira Yamaguchi
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Meguro, Tokyo, 152-8552, Japan
| | - Shusaku Shoji
- Department of Materials Science & Engineering, Cornell University, Ithaca, New York, 14853-1501, United States
| | - Shigenori Ueda
- National Institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan
| | - Ayako Hashimoto
- National Institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8571, Japan
| | - Yu Wen
- National Institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan
- Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8571, Japan
| | - Aufandra Cakra Wardhana
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Meguro, Tokyo, 152-8552, Japan
| | - Ji-Eun Lee
- Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science, Wako, Saitama, 351-0198, Japan
| | - Min Liu
- Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, School of Physical and Electronics, Central South University, Changsha 410083, Public Republic of China
| | - Hideki Abe
- National Institute for Materials Science, Tsukuba, Ibaraki, 305-0044, Japan
- Graduate School of Science and Technology, Saitama University, Saitama 338-8570, Japan
| | - Masahiro Miyauchi
- Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Meguro, Tokyo, 152-8552, Japan
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Alebachew N, Murthy HCA, Gonfa BA, von Eschwege KG, Langner EHG, Coetsee E, Demissie TB. Nanocomposites with ZrO 2@S-Doped g-C 3N 4 as an Enhanced Binder-Free Sensor: Synthesis and Characterization. ACS OMEGA 2023; 8:13775-13790. [PMID: 37091396 PMCID: PMC10116625 DOI: 10.1021/acsomega.2c08174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Accepted: 03/22/2023] [Indexed: 05/03/2023]
Abstract
This study describes new electrocatalyst materials that can detect and reduce environmental pollutants. The synthesis and characterization of semiconductor nanocomposites (NCs) made from active ZrO2@S-doped g-C3N4 is presented. Electrochemical impedance spectroscopy (EIS) and Mott-Schottky (M-S) measurements were used to examine electron transfer characteristics of the synthesized samples. Using X-ray diffraction (XRD) and high-resolution scanning electron microscopy (HR-SEM) techniques, inclusion of monoclinic ZrO2 on flower-shaped S-doped-g-C3N4 was visualized. High-resolution X-ray photoelectron spectroscopy (XPS) revealed successful doping of ZrO2 into the lattice of S-doped g-C3N4. The electron transport mechanism between the electrolyte and the fluorine tin-oxide electrode (FTOE) was enhanced by the synergistic interaction between ZrO2 and S-doped g-C3N4 as co-modifiers. Development of a platform with improved conductivity based on an FTOE modified with ZrO2@S-doped g-C3N4 NCs resulted in an ideal platform for the detection of 4-nitrophenol (4-NP) in water. The electrocatalytic activity of the modified electrode was evaluated through determination of 4-NP by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) under optimum conditions (pH 5). ZrO2@S-doped g-C3N4 (20%)/FTOE exhibited good electrocatalytic activity with a linear range from 10 to 100 μM and a low limit of detection (LOD) of 6.65 μM. Typical p-type semiconductor ZrO2@S-doped g-C3N4 NCs significantly impact the superior detection of 4-NP due to its size, shape, optical properties, specific surface area and effective separation of electron-hole pairs. We conclude that the superior electrochemical sensor behavior of the ZrO2@S-doped g-C3N4 (20%)/FTOE surfaces results from the synergistic interaction between S-doped g-C3N4 and ZrO2 surfaces that produce an active NC interface.
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Affiliation(s)
- Nigussie Alebachew
- Department
of Applied Chemistry, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama 251, Ethiopia
| | - H. C. Ananda Murthy
- Department
of Applied Chemistry, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama 251, Ethiopia
- Department
of Prosthodontics, Saveetha Dental College & Hospital, Saveetha Institute of Medical and Technical Science
(SIMATS), Saveetha University, Chennai 600077, Tamil
Nadu, India
| | - Bedasa Abdisa Gonfa
- Department
of Applied Chemistry, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama 251, Ethiopia
| | - Karel G. von Eschwege
- Department
of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - Ernst H. G. Langner
- Department
of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - Elizabeth Coetsee
- Department
of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA9310, South Africa
| | - Taye B. Demissie
- Department
of Chemistry, University of Botswana, P.bag UB 00704 Gaborone, Botswana
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Carbon nanosheets coated on zirconium oxide nanoplate nanocomposite for Zn2+ ion adsorption and reuse of spent adsorbent for fingerprint detection. KOREAN J CHEM ENG 2023. [DOI: 10.1007/s11814-022-1187-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/20/2023]
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10
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Kumari P, Saha R, Saikia G, Bhujel A, Choudhury MG, Jagdale P, Paul S. Synthesis of Mixed-Phase TiO 2-ZrO 2 Nanocomposite for Photocatalytic Wastewater Treatment. TOXICS 2023; 11:234. [PMID: 36976999 PMCID: PMC10051327 DOI: 10.3390/toxics11030234] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/20/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
The use of TiO2 nanoparticles for photocatalysis for the degradation of organic dyes under UV light for wastewater treatment has been widely studied. However, the photocatalytic characteristics of TiO2 nanoparticles are inadequate due to their UV light response and higher band gap. In this work, three nanoparticles were synthesized: (i) TiO2 nanoparticle was synthesized by a sol-gel process. (ii) ZrO2 was prepared using a solution combustion process and (iii) mixed-phase TiO2-ZrO2 nanoparticles were synthesized by a sol-gel process to remove Eosin Yellow (EY) from aqueous solutions in the wastewater. XRD, FTIR, UV-VIS, TEM, and XPS analysis methods were used to examine the properties of the synthesized products. The XRD investigation supported the tetragonal and monoclinic crystal structures of the TiO2 and ZrO2 nanoparticles. TEM studies identified that mixed-phase TiO2-ZrO2 nanoparticles have the same tetragonal structure as pure mixed-phase. The degradation of Eosin Yellow (EY) was examined using TiO2, ZrO2, and mixed-phase TiO2-ZrO2 nanoparticles under visible light. The results confirmed that the mixed-phase TiO2-ZrO2nanoparticles show a higher level of photocatalytic activity, and the process is accomplished at a high degradation rate in lesser time and at a lower power intensity.
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Affiliation(s)
- Pooja Kumari
- Advanced Materials Research and Energy Application Laboratory (AMREAL), Department of Energy Engineering, North-Eastern Hill University, Shillong 793022, India
| | - Rajib Saha
- Advanced Materials Research and Energy Application Laboratory (AMREAL), Department of Energy Engineering, North-Eastern Hill University, Shillong 793022, India
| | - Gaurav Saikia
- Advanced Materials Research and Energy Application Laboratory (AMREAL), Department of Energy Engineering, North-Eastern Hill University, Shillong 793022, India
| | - Aditya Bhujel
- Advanced Materials Research and Energy Application Laboratory (AMREAL), Department of Energy Engineering, North-Eastern Hill University, Shillong 793022, India
| | - Mahua Gupta Choudhury
- Advanced Materials Research and Energy Application Laboratory (AMREAL), Department of Energy Engineering, North-Eastern Hill University, Shillong 793022, India
| | - Pravin Jagdale
- Department of Applied Science and Technology, Politecnico di Torino, 10129 Turin, Italy
| | - Samrat Paul
- Advanced Materials Research and Energy Application Laboratory (AMREAL), Department of Energy Engineering, North-Eastern Hill University, Shillong 793022, India
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11
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Kanungo SS, Mishra AK, Mhamane NB, Marelli UK, Kumar D, Gopinath CS. Possible Fine-Tuning of Methane Activation toward C2 Oxygenates by 3d-Transition Metal-Ions Doped Nano-Ceria-Zirconia. Inorg Chem 2022; 61:19577-19587. [DOI: 10.1021/acs.inorgchem.2c03493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Subhashree S. Kanungo
- Catalysis and Inorganic Chemistry Division, CSIR─National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Abhaya Kumar Mishra
- Catalysis and Inorganic Chemistry Division, CSIR─National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India
| | - Nitin B. Mhamane
- Catalysis and Inorganic Chemistry Division, CSIR─National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
| | - Udaya Kiran Marelli
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
- Organic Chemistry Division, CSIR─National Chemical Laboratory, Pune 411 008, India
| | - Dharmesh Kumar
- Shell Technology Centre, Hardware Park, Bengaluru, Karnataka 562149, India
- Qatar Shell Research and Technology Centre, QSTP, P.O. Box 3747, Doha 3747, Qatar
| | - Chinnakonda S. Gopinath
- Catalysis and Inorganic Chemistry Division, CSIR─National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India
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Pinheiro Araújo T, Mondelli C, Agrachev M, Zou T, Willi PO, Engel KM, Grass RN, Stark WJ, Safonova OV, Jeschke G, Mitchell S, Pérez-Ramírez J. Flame-made ternary Pd-In2O3-ZrO2 catalyst with enhanced oxygen vacancy generation for CO2 hydrogenation to methanol. Nat Commun 2022; 13:5610. [PMID: 36153333 PMCID: PMC9509363 DOI: 10.1038/s41467-022-33391-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/15/2022] [Indexed: 11/28/2022] Open
Abstract
Palladium promotion and deposition on monoclinic zirconia are effective strategies to boost the performance of bulk In2O3 in CO2-to-methanol and could unlock superior reactivity if well integrated into a single catalytic system. However, harnessing synergic effects of the individual components is crucial and very challenging as it requires precise control over their assembly. Herein, we present ternary Pd-In2O3-ZrO2 catalysts prepared by flame spray pyrolysis (FSP) with remarkable methanol productivity and improved metal utilization, surpassing their binary counterparts. Unlike established impregnation and co-precipitation methods, FSP produces materials combining low-nuclearity palladium species associated with In2O3 monolayers highly dispersed on the ZrO2 carrier, whose surface partially transforms from a tetragonal into a monoclinic-like structure upon reaction. A pioneering protocol developed to quantify oxygen vacancies using in situ electron paramagnetic resonance spectroscopy reveals their enhanced generation because of this unique catalyst architecture, thereby rationalizing its high and sustained methanol productivity. Assembling multicomponent catalysts to harness synergic effects is challenging. Now, flame spray pyrolysis permits the synthesis of ternary Pd-In2O3-ZrO2 catalysts with an optimal architecture and an enriched density of oxygen vacancies for maximal performance in CO2-based methanol synthesis.
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Control of monomeric Vo's versus Vo clusters in ZrO 2-x for solar-light H 2 production from H 2O at high-yield (millimoles gr -1 h -1). Sci Rep 2022; 12:15132. [PMID: 36071088 PMCID: PMC9452565 DOI: 10.1038/s41598-022-19382-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 08/29/2022] [Indexed: 11/08/2022] Open
Abstract
Pristine zirconia, ZrO2, possesses high premise as photocatalyst due to its conduction band energy edge. However, its high energy-gap is prohibitive for photoactivation by solar-light. Currently, it is unclear how solar-active zirconia can be designed to meet the requirements for high photocatalytic performance. Moreover, transferring this design to an industrial-scale process is a forward-looking route. Herein, we have developed a novel Flame Spray Pyrolysis process for generating solar-light active nano-ZrO2−x via engineering of lattice vacancies, Vo. Using solar photons, our optimal nano-ZrO2−x can achieve milestone H2-production yield, > 2400 μmolg−1 h−1 (closest thus, so far, to high photocatalytic water splitting performance benchmarks). Visible light can be also exploited by nano-ZrO2−x at a high yield via a two-photon process. Control of monomeric Vo versus clusters of Vo’s is the key parameter toward Highly-Performing-Photocatalytic ZrO2−x. Thus, the reusable and sustainable ZrO2−x catalyst achieves so far unattainable solar activated photocatalysis, under large scale production.
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An Electrochemical Investigation of Methanol Oxidation on Thin Films of Nickel Oxide and Its Composites with Zirconium and Yttrium Oxides. CRYSTALS 2022. [DOI: 10.3390/cryst12040534] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The present work is focused on the fabrication of NiO-ZrO2/FTO and NiO-Y2O3/FTO thin films via a simple dip-coating method. The films are deposited from precursor solutions of Ni(CH3COO)2·2H2O, Zr(CH3COO)4, Y(CH3COO)3·H2O in methanol. The synthesized films, after proper characterization, are employed for electrochemical oxidation of methanol. The analytical techniques such as X-ray diffraction (XRD), Raman, and Infrared (IR) spectroscopy reveal the successful formation of crystalline thin films of mixed metal oxide without any additional impurities. Further, X-ray photoelectron spectroscopy (XPS) results, confirm the composition and oxidation state of all the elements present in thin films. The field emission scanning electron microscopy (FESEM) further aided to identify the uniformity and porous nature of composite thin films while the energy-dispersive X-ray spectroscopy (EDS) confirms the targeted elemental composition of the prepared thin films is in good agreement with precursors. The electrochemical oxidation of methanol results reveals that NiO-Y2O3/FTO and NiO-ZrO2/FTO thin films showed current densities of 6.2 mA/cm2 and 10 mA/cm2 at 0.65 V, respectively, against Ag/AgCl/3M KCl using 0.6 M methanol solution. Furthermore, Chronoamperometric (CA) results show good stability of NiO-ZrO2/FTO and NiO-Y2O3/FTO thin films with observed current decay of 10% and 6.8% of the initial current density, respectively. Moreover, the effect of scan rate and concentration of metals in a catalyst was also investigated. The Electrochemical impedance studies (EIS) further support electrochemical results, where the lower charge transfer resistance (Rct) values are recorded for composite thin films as compared to the pure metal oxide thin films (NiO/FTO, ZrO2/FTO, and Y2O3/FTO).
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Design Control of Copper-Doped Titania–Zirconia Catalysts for Methanol Decomposition and Total Oxidation of Ethyl Acetate. Symmetry (Basel) 2022. [DOI: 10.3390/sym14040751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This study is focused on the design control of Cu–Zr–Ti oxide composites by the variation of the Zr/Ti ratio and the copper deposition procedure used. For the first time, these ternary composites were obtained by a combination of template-assisted hydrothermal techniques for the preparation of mesoporous ZrO2–TiO2 mixed oxides with diverse compositions, followed by the consecutive chemisorption and hydrolysis of copper ammonia complexes on them. The nitrogen physisorption, XRD, SEM, HRTEM, TPR, XPS, UV-Vis, and Raman spectroscopies were applied for the catalysts’ characterization. Methanol decomposition and the total oxidation of ethyl acetate, both of which with potential for sustainable environmental protection, were used as catalytic tests. The complex relationship between the phase composition, structure, and morphology of titania–zirconia mixed oxides and the state and catalytic behavior of the copper oxide species supported on them was investigated. In comparison with the conventional impregnation technique, the novel preparation procedure revealed the generation of more uniform and homogeneously dispersed needle-like copper oxide crystallites in the mesoporous TiO2–ZrO2 host matrix, which typically ensure improved catalytic performance. The synergistic activity between the loaded copper species and TiO2–ZrO2 support was discussed. All ternary composites exhibited superior catalytic activity in total oxidation of ethyl acetate. The specific behavior of the catalysts in methanol decomposition was related to the irreversible phase transformations by the influence of the reaction medium.
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Rabo JR, Takayanagi M, Tsuchiya T, Nakajima H, Terabe K, Cervera RBM. Effects of Oxygen Partial Pressure and Substrate Temperature on the Structure and Morphology of Sc and Y Co-Doped ZrO 2 Solid Electrolyte Thin Films Prepared via Pulsed Laser Deposition. MATERIALS 2022; 15:ma15020410. [PMID: 35057125 PMCID: PMC8778154 DOI: 10.3390/ma15020410] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 01/01/2022] [Accepted: 01/04/2022] [Indexed: 01/27/2023]
Abstract
Scandium (Sc) and yttrium (Y) co-doped ZrO2 (ScYSZ) thin films were prepared on a SiO2-Si substrate via pulsed laser deposition (PLD) method. In order to obtain good quality thin films with the desired microstructure, various oxygen partial pressures (PO2) from 0.01 Pa to 10 Pa and substrate temperatures (Ts) from 25 °C to 800 °C were investigated. X-ray diffraction (XRD) patterns results showed that amorphous ScYSZ thin films were formed at room substrate temperature while cubic polycrystalline thin films were obtained at higher substrate temperatures (Ts = 200 °C, 400 °C, 600 °C, 800 °C). Raman spectra revealed a distinct Raman shift at around 600 cm−1 supporting a cubic phase. However, a transition from cubic to tetragonal phase can be observed with increasing oxygen partial pressure. Photoemission spectroscopy (PES) spectra suggested supporting analysis that more oxygen vacancies in the lattice can be observed for samples deposited at lower oxygen partial pressures resulting in a cubic structure with higher dopant cation binding energies as compared to the tetragonal structure observed at higher oxygen partial pressure. On the other hand, dense morphologies can be obtained at lower PO2 (0.01 Pa and 0.1 Pa) while more porous morphologies can be obtained at higher PO2 (1.0 Pa and 10 Pa).
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Affiliation(s)
- Jennet R. Rabo
- Energy Storage and Conversion Materials Laboratory, Department of Mining, Metallurgical and Materials Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines;
| | - Makoto Takayanagi
- International Center for Materials Nanoarchitectonics (WIPI-MANA), National Institute for Materials Science, Tsukuba 305-0044, Ibaraki Prefecture, Japan; (M.T.); (T.T.); (K.T.)
| | - Takashi Tsuchiya
- International Center for Materials Nanoarchitectonics (WIPI-MANA), National Institute for Materials Science, Tsukuba 305-0044, Ibaraki Prefecture, Japan; (M.T.); (T.T.); (K.T.)
| | - Hideki Nakajima
- Synchrotron Light Research Institute, Nakhon Ratchasima 30000, Thailand;
| | - Kazuya Terabe
- International Center for Materials Nanoarchitectonics (WIPI-MANA), National Institute for Materials Science, Tsukuba 305-0044, Ibaraki Prefecture, Japan; (M.T.); (T.T.); (K.T.)
| | - Rinlee Butch M. Cervera
- Energy Storage and Conversion Materials Laboratory, Department of Mining, Metallurgical and Materials Engineering, University of the Philippines Diliman, Quezon City 1101, Philippines;
- Correspondence: ; Tel.: +66-(632)-8981-8500 (ext. 3169)
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Rui N, Shi R, Gutiérrez RA, Rosales R, Kang J, Mahapatra M, Ramírez PJ, Senanayake SD, Rodriguez JA. CO 2 Hydrogenation on ZrO 2/Cu(111) Surfaces: Production of Methane and Methanol. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c03229] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ning Rui
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Rui Shi
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Ramón A. Gutiérrez
- Facultad de Ciencias, Universidad Central de Venezuela, Caracas 1020-A, Venezuela
| | - Rina Rosales
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Jindong Kang
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Mausumi Mahapatra
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Pedro J. Ramírez
- Facultad de Ciencias, Universidad Central de Venezuela, Caracas 1020-A, Venezuela
- Zoneca-CENEX, R&D Laboratories, Alta Vista, 64770 Monterrey Mexico
| | - Sanjaya D. Senanayake
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - José A. Rodriguez
- Chemistry Division, Brookhaven National Laboratory, Upton, New York 11973, United States
- Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States
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Microwave assisted sol-gel synthesis of bioactive zirconia nanoparticles – Correlation of strength and structure. J Mech Behav Biomed Mater 2020; 112:104012. [DOI: 10.1016/j.jmbbm.2020.104012] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 11/21/2022]
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Carbide-Modified Pd on ZrO2 as Active Phase for CO2-Reforming of Methane—A Model Phase Boundary Approach. Catalysts 2020. [DOI: 10.3390/catal10091000] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Starting from subsurface Zr0-doped “inverse” Pd and bulk-intermetallic Pd0Zr0 model catalyst precursors, we investigated the dry reforming reaction of methane (DRM) using synchrotron-based near ambient pressure in-situ X-ray photoelectron spectroscopy (NAP-XPS), in-situ X-ray diffraction and catalytic testing in an ultrahigh-vacuum-compatible recirculating batch reactor cell. Both intermetallic precursors develop a Pd0–ZrO2 phase boundary under realistic DRM conditions, whereby the oxidative segregation of ZrO2 from bulk intermetallic PdxZry leads to a highly active composite layer of carbide-modified Pd0 metal nanoparticles in contact with tetragonal ZrO2. This active state exhibits reaction rates exceeding those of a conventional supported Pd–ZrO2 reference catalyst and its high activity is unambiguously linked to the fast conversion of the highly reactive carbidic/dissolved C-species inside Pd0 toward CO at the Pd/ZrO2 phase boundary, which serves the role of providing efficient CO2 activation sites. In contrast, the near-surface intermetallic precursor decomposes toward ZrO2 islands at the surface of a quasi-infinite Pd0 metal bulk. Strongly delayed Pd carbide accumulation and thus carbon resegregation under reaction conditions leads to a much less active interfacial ZrO2–Pd0 state.
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20
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Zhang Y, Zhao Y, Otroshchenko T, Perechodjuk A, Kondratenko VA, Bartling S, Rodemerck U, Linke D, Jiao H, Jiang G, Kondratenko EV. Structure–Activity–Selectivity Relationships in Propane Dehydrogenation over Rh/ZrO2 Catalysts. ACS Catal 2020. [DOI: 10.1021/acscatal.0c01455] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yaoyuan Zhang
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, People’s Republic of China
| | - Yun Zhao
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
| | - Tatiana Otroshchenko
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
| | - Anna Perechodjuk
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
| | - Vita A. Kondratenko
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
| | - Stephan Bartling
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
| | - Uwe Rodemerck
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
| | - David Linke
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
| | - Haijun Jiao
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
| | - Guiyuan Jiang
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing, 102249, People’s Republic of China
| | - Evgenii V. Kondratenko
- Leibniz-Institut für Katalyse e.V. an der Universität Rostock, Albert-Einstein-Straße 29a, Rostock 18059, Germany
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21
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Lackner P, Brandt AJ, Diebold U, Schmid M. Few-monolayer yttria-doped zirconia films: Segregation and phase stabilization. J Chem Phys 2020; 152:064709. [PMID: 32061213 DOI: 10.1063/1.5140266] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
For most applications, zirconia (ZrO2) is doped with yttria. Doping leads to the stabilization of the tetragonal or cubic phase and increased oxygen ion conductivity. Most previous surface studies of yttria-doped zirconia were plagued by impurities, however. We have studied doping of pure, 5-monolayer ZrO2 films on Rh(111) by x-ray photoelectron spectroscopy (XPS), scanning tunneling microscopy (STM), and low-energy electron diffraction (LEED). STM and LEED show that the tetragonal phase is stabilized by unexpectedly low dopant concentrations, 0.5 mol % Y2O3, even when the films are essentially fully oxidized (as evidenced by XPS core level shifts). XPS also shows Y segregation to the surface with an estimated segregation enthalpy of -23 ± 4 kJ/mol.
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Affiliation(s)
- Peter Lackner
- Institute of Applied Physics, TU Wien, 1040 Vienna, Austria
| | - Amy J Brandt
- Institute of Applied Physics, TU Wien, 1040 Vienna, Austria
| | - Ulrike Diebold
- Institute of Applied Physics, TU Wien, 1040 Vienna, Austria
| | - Michael Schmid
- Institute of Applied Physics, TU Wien, 1040 Vienna, Austria
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