Local Structure and Chemistry of C‐Doped ZnO@C Core–Shell Nanostructures with Room‐Temperature Ferromagnetism

Ngo, Duc‐The; Cuong, Le Thanh; Cuong, Nguyen Huu; Son, Cao Thai; Huy, Phạm Thành; Dung, Nguyen Duc

doi:10.1002/adfm.201704567

Cited by 19 publications

(4 citation statements)

References 44 publications

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“…[ 75 ] Moreover, utilizing the total scattering atomic pair distribution function (PDF) method could also confirm the aforementioned subtle bond length differences and structural inhomogeneity of alloy catalysts. [ 76,77 ] Furthermore, XAS signals can be used for 3D chemical tomography imaging of catalysts via computer postprocessing during the electrocatalytic reactions. Operando computed tomography (CT) coupled with XANES unveiled the degradation phenomenon‐of a polymer electrolyte fuel cell.…”

Section: Discussionmentioning

confidence: 99%

Application of X‐Ray Absorption Spectroscopy in Electrocatalytic Water Splitting and CO₂ Reduction

et al. 2021

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Renewable energy conversion and storage are crucial in aiding the worldwide efforts to replace fossil fuels and achieve carbon neutrality. In particular, electrocatalytic water splitting to obtain H2 and CO2 reduction to high‐value‐added fuels can lead to an epoch of hydrogen energy and a closed‐loop carbon cycle. Although many reported electrocatalysts have demonstrated outstanding performance at the laboratory scale, the origin of the superior electrocatalytic activity and selectivity and the structural evolution of these catalysts remain ambiguous. For this purpose, operando techniques are able to combine the characterizations of the catalyst with measurement of its performance under real working conditions. Herein, a critical overview of recent developments in understanding the underlying mechanisms of water splitting and CO2 reduction is presented, emphasizing the advanced operando X‐ray absorption spectroscopy characterization of these two electrocatalytic reactions. Some perceptions of the rising X‐ray technique directions and the foreground in this field are also presented.

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Section: Discussionmentioning

confidence: 99%

Application of X‐Ray Absorption Spectroscopy in Electrocatalytic Water Splitting and CO₂ Reduction

et al. 2021

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“…In 2018, Ngo et al . 85 experimentally demonstrated that migration of C atoms into ZnO crystal to substitute O vacancies C-Doped ZnO@C Core–Shell Nanostructures and proposed that the s–p and p–p hybridizations formed by C2p–Zn4s, and O2p–C2p orbitals are believed to cause ferromagnetism. Beltrán et al 47 suggested that the presence of C O defects, with carbon atoms on an oxygen site, is the likely source of the magnetic moments, which may interact ferromagnetically via the mediation of oxygen atoms.…”

Section: Resultsmentioning

confidence: 99%

Defects mediated weak ferromagnetism in Zn1−yCyO (0.00 ≤ y ≤ 0.10) nanorods semiconductors for spintronics applications

Awan,

Akhtar,

Hussain

et al. 2023

Sci Rep

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A series of carbon-doped ZnO [Zn1−yCyO (0.00 ≤ y ≤ 0.10)] nanorods were synthesized using a cost-effective low-temperature (85 °C) dip coating technique. X-ray diffractometer scans of the samples revealed the hexagonal structure of the C-doped ZnO samples, except for y = 0.10. XRD analysis confirmed a decrease in the unit cell volume after doping C into the ZnO matrix, likely due to the incorporation of carbon at oxygen sites (CO defects) resulting from ionic size differences. The morphological analysis confirmed the presence of hexagonal-shaped nanorods. X-ray photoelectron spectroscopy identified C–Zn–C bonding, i.e., CO defects, Zn–O–C bond formation, O–C–O bonding, oxygen vacancies, and sp2-bonded carbon in the C-doped ZnO structure with different compositions. We analyzed the deconvoluted PL visible broadband emission through fitted Gaussian peaks to estimate various defects for electron transition within the bandgap. Raman spectroscopy confirmed the vibrational modes of each constituent. We observed a stronger room-temperature ferromagnetic nature in the y = 0.02 composition with a magnetization of 0.0018 emu/cc, corresponding to the highest CO defects concentration and the lowest measured bandgap (3.00 eV) compared to other samples. Partial density of states analysis demonstrated that magnetism from carbon is dominant due to its p-orbitals. We anticipate that if carbon substitutes oxygen sites in the ZnO structure, the C-2p orbitals become localized and create two holes at each site, leading to enhanced p–p type interactions and strong spin interactions between carbon atoms and carriers. This phenomenon can stabilize the long-range order of room-temperature ferromagnetism properties for spintronic applications.

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“…Such combined setups will provide the relevant data to formulate robust structure -performance relationships as they avoid difficulties in reproducing identical conditions with different setups (for the respective individual techniques). In addition, we expect a rapid growth of PDF applications with recent advances in laboratory based X-ray PDF systems [46,[82][83][84][85] as well as e-PDF [51,[86][87][88][89][90][91]. Such developments will increase the accessibility to the method which despite the increasing number of beamlines suited for PDF studies at large-scale facilities, is still limited.…”

Section: Concluding Remarks and Future Perspectivesmentioning

confidence: 99%

Uncovering the Structure of Heterogeneous Catalysts Using Atomic Pair Distribution Function Analysis

Zimmerli

Müller

Abdala

2022

Preprint

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Heterogeneous catalysts are complex materials, often containing multiple atomic species and phases with various degrees of structural order. The identification of structure – performance relationships that rely on the availability of advanced structural characterization tools, is key for a rational catalyst design. Structural descriptors in catalysts can be defined over different length scales from several Å up to several nanometers (crystalline structure), requiring structural characterization techniques covering these different length scales. Pair distribution function (PDF) analysis is a powerful method to extract structural information spanning from the atomic to the nanoscale under in situ or operando conditions. We discuss recent advances using PDF to provide insight into the atomic-to-nanoscale structure of heterogeneous catalysts.

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Local Structure and Chemistry of C‐Doped ZnO@C Core–Shell Nanostructures with Room‐Temperature Ferromagnetism

Cited by 19 publications

References 44 publications

Application of X‐Ray Absorption Spectroscopy in Electrocatalytic Water Splitting and CO₂ Reduction

Application of X‐Ray Absorption Spectroscopy in Electrocatalytic Water Splitting and CO₂ Reduction

Defects mediated weak ferromagnetism in Zn1−yCyO (0.00 ≤ y ≤ 0.10) nanorods semiconductors for spintronics applications

Uncovering the Structure of Heterogeneous Catalysts Using Atomic Pair Distribution Function Analysis

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Local Structure and Chemistry of C‐Doped ZnO@C Core–Shell Nanostructures with Room‐Temperature Ferromagnetism

Cited by 19 publications

References 44 publications

Application of X‐Ray Absorption Spectroscopy in Electrocatalytic Water Splitting and CO2 Reduction

Application of X‐Ray Absorption Spectroscopy in Electrocatalytic Water Splitting and CO2 Reduction

Defects mediated weak ferromagnetism in Zn1−yCyO (0.00 ≤ y ≤ 0.10) nanorods semiconductors for spintronics applications

Uncovering the Structure of Heterogeneous Catalysts Using Atomic Pair Distribution Function Analysis

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Product

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Application of X‐Ray Absorption Spectroscopy in Electrocatalytic Water Splitting and CO₂ Reduction

Application of X‐Ray Absorption Spectroscopy in Electrocatalytic Water Splitting and CO₂ Reduction