Structural, optical, and XPS studies of doped yttria for superior water splitting under visible light illumination

Reddy, I. Neelakanta; Reddy, Ch. Venkata; Cho, Migyung; Kim, Dongseob; Shim, Jaesool

doi:10.1016/j.jelechem.2019.113335

Cited by 13 publications

(7 citation statements)

References 54 publications

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“…The Y 3 d (Fig. 3c, e ) spectra showed the Y 3+ species for both samples 42 – 44 . The main difference was that Y 3+ in Y 2 O 3 was mainly detected from the fresh sample; but for the used samples, it was mainly Y carbonate.…”

Section: Resultsmentioning

confidence: 88%

Catalytically efficient Ni-NiOx-Y2O3 interface for medium temperature water-gas shift reaction

Yan

Wang

et al. 2022

Nat Commun

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The metal-support interfaces between metals and oxide supports have long been studied in catalytic applications, thanks to their significance in structural stability and efficient catalytic activity. The metal-rare earth oxide interface is particularly interesting because these early transition cations have high electrophilicity, and therefore good binding strength with Lewis basic molecules, such as H2O. Based on this feature, here we design a highly efficient composite Ni-Y2O3 catalyst, which forms abundant active Ni-NiOx-Y2O3 interfaces under the water-gas shift (WGS) reaction condition, achieving 140.6 μmolCO gcat−1 s−1 rate at 300 °C, which is the highest activity for Ni-based catalysts. A combination of theory and ex/in situ experimental study suggests that Y2O3 helps H2O dissociation at the Ni-NiOx-Y2O3 interfaces, promoting this rate limiting step in the WGS reaction. Construction of such new interfacial structure for molecules activation holds great promise in many catalytic systems.

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Section: Resultsmentioning

confidence: 88%

Catalytically efficient Ni-NiOx-Y2O3 interface for medium temperature water-gas shift reaction

Yan

Wang

et al. 2022

Nat Commun

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“…By comparison, the content of Co 2+ in NiY/C@Co/C is more than that in Co/C, and it is speculated that the Co-N sites may improve the ORR performance . In Figure h, the Ni 2p spectra of NiY/C@Co/C indicate the existence of Ni° (∼853.9 and ∼871.3 eV), Ni 2+ (∼856.7 and ∼874.5 eV), and satellite peak (∼861.3 and ∼879.5 eV). , Notably, the high-resolution Y 3d spectra of NiY/C@Co/C (Figure i) and NiY/C (Figure S7h) showed four outstanding peaks, Y 2 O 3 (∼156.96 and ∼159.11 eV), Y(OH) 3 (∼157.9 and 160.4 eV), respectively. ,, The region around Y 2 O 3 where Y–O bonds exist may be the catalytically active region where oxygen precipitation reactions occur, converting H 2 O to O 2 . , That is, the Y species in the NiY/C@Co/C and NiY/C materials exists in the form of Y 2 O 3 , which is a critical factor in the catalytic process. The high-resolution XPS spectra of O 1s in NiY/C@Co/C show the asymmetric peak shape of O 1s (Figure S8), indicating that the O 2– and Y 3+ occupy multiple coordination and bonding states in the crystal structure.…”

Section: Resultsmentioning

confidence: 93%

“…42,50 Notably, the high-resolution Y 3d spectra of NiY/C@Co/C (Figure 2i) and NiY/C (Figure S7h) showed four outstanding peaks, Y 2 O 3 (∼156.96 and ∼159.11 eV), Y(OH) 3 (∼157.9 and 160.4 eV), respectively. 47,51,52 The region around Y 2 O 3 where Y−O bonds exist may be the catalytically active region where oxygen precipitation reactions occur, converting H 2 O to O 2 . 54,55 That is, the Y species in the NiY/C@Co/C and NiY/C materials exists in the form of Y 2 O 3 , which is a critical factor in the catalytic process.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Rare-Earth-Based Bimetallic Metal–Organic Frameworks Promote Oxygen Electrocatalysis for Rechargeable Zn–Air Batteries

Liu

Peng

Kang

et al. 2022

ACS Sustainable Chem. Eng.

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Metal−organic frameworks (MOF) are versatile and good structurally stable materials that are widely used in energy conversion and storage. In this work, rare-earth-based bimetallic metal−organic framework (NiY-BTC) nanorods anchored with transition metal−organic frameworks (ZIF-67) were used as versatile precursors to prepare novel metal/rare-earth metal oxidecoupled carbon-based bifunctional oxygen electrocatalysts (NiY/C@Co/C). Due to the stable nanorods framework structure, appropriate Y 2 O 3 active center, and richness of Co−N sites in the carbon skeletons, the NiY/C@Co/C catalyst exhibits high onset potentials (E onset = 0.928 V) and half-wave potential (E 1/2 = 0.83 V) for the oxygen reduction reaction (ORR), and expresses a low overpotential (η = 392 mV@10 mA cm −2 ) for the oxygen evolution reaction (OER). Moreover, a rechargeable Zn−air battery assembled with NiY/C@Co/C as the air cathode catalyst displayed a great specific capacity (899.6 mAh gZn −1 ) and a remarkable peak power density of 102.2 mW cm −2 , as well as excellent durability and stability. This work delivers a way using rare-earth metal− organic frameworks to get the corresponding metal oxide-coupled carbon-based bifunctional oxygen electrocatalysts for rechargeable Zn−air batteries.

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“…Such metal oxides described act as heterogeneous photocatalysts, as they are wide band gap n-doped semiconductors. 17 Such materials are suitable for the photo-oxidation of water due to their high-potential valence band positions, surpassing the oxygen evolution potential of water. 2 Therefore, photogenerated holes will be transferred into the solution, a process which is accelerated in high surface area materials.…”

Section: Introductionmentioning

confidence: 99%

“…Such metal oxides described act as heterogeneous photocatalysts, as they are wide band gap n-doped semiconductors . Such materials are suitable for the photo-oxidation of water due to their high-potential valence band positions, surpassing the oxygen evolution potential of water .…”

Section: Introductionmentioning

confidence: 99%

Goethite and Hematite Hybrid Nanosheet-Decorated YZnO NRs for Efficient Solar Water Splitting

et al. 2021

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Hybrid metal-oxide nanostructures have drawn much attention recently because of their ability to overcome the disadvantages of each individual material to achieve high-performance solar water splitting. Using anodic electrochemical deposition, hybrid polycrystalline goethite (α-FeOOH) and hematite (α-Fe2O3) nanosheets (GOE/HM NSs) were successfully synthesized on yttrium-doped ZnO nanorods (YZO NRs). The unique morphology, with GOE/HM NSs wrapped around the length of vertically aligned YZO NRs, is favorable for light harvesting, charge transfer, and charge transportation. The density and the effective surface area of NSs were optimized for achieving a fine balance between light absorption and charge transportation between the photoanode and the electrolyte. The samples showed much improved water splitting efficiency under both UV and visible-light excitation, which represents the synergistic effects of GEO/HM NSs with YZO NRs. UV–vis absorption and incident photon-to-current conversion efficiency measurements demonstrated appropriate band alignment at interfaces, in addition to the reduced band gap energy. Electrochemical impedance spectroscopy measurements showed greatly reduced charge-transfer resistance. The hybrid material achieved an increase in the water splitting ability by a factor of 4.5 from pristine ZnO NRs (0.2 mA cm–2) to GOE/HM NSs-coated YZO NRs (0.92 mA cm–2). This represents a highly competitive strategy for improving the ability of ZnO for water splitting.

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Structural, optical, and XPS studies of doped yttria for superior water splitting under visible light illumination

Cited by 13 publications

References 54 publications

Catalytically efficient Ni-NiOx-Y2O3 interface for medium temperature water-gas shift reaction

Catalytically efficient Ni-NiOx-Y2O3 interface for medium temperature water-gas shift reaction

Rare-Earth-Based Bimetallic Metal–Organic Frameworks Promote Oxygen Electrocatalysis for Rechargeable Zn–Air Batteries

Goethite and Hematite Hybrid Nanosheet-Decorated YZnO NRs for Efficient Solar Water Splitting

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