Alkaline-Earth Metals-Doped Pyrochlore Gd2Zr2O7 as Oxygen Conductors for Improved NO2 Sensing Performance

Zhong, Fulan; Zhao, Jiwu; Shi, Lanqian; Xiao, Yihong; Cai, Guojun; Zheng, Yong; Long, Jinlin

doi:10.1038/s41598-017-04920-1

Cited by 39 publications

(13 citation statements)

References 45 publications

(36 reference statements)

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“…At higher doping levels, the lattice parameter remained essentially constant up to x = 0.15. Starting at 5% substitution (Gd 1.9 Ca 0.1 Zr 2 O 6.95 ), diffraction lines of a second phase, perovskite GdZrO 3 , were observed [38]. These data are completely consistent with our results (Table 2).…”

Section: Resultssupporting

confidence: 90%

“…In this case, we also assume the presence of a small amount (under 5%) of a second phase, based on perovskite CaZrO 3 . Recently, a series of Gd 2−x Ca x Zr 2 O 7−x/2 (x = 0, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3) solid solutions was synthesized by a hydrothermal process followed by annealing at 1500 °C for 4 h [38]. The lattice parameter of Gd 1.95 Ca 0.05 Zr 2 O 6.975 (2.5% substitution) was found to exceed that of undoped Gd 2 Zr 2 O 7 .…”

Section: Resultsmentioning

confidence: 99%

“…As in the case of the Sm 2−x Ca x Zr 2 O 7−x/2 (x = 0.1) solid solution, we assume that a high-conductivity of Gd-doped phase is due to cubic perovskite CaZrO 3 , which could be present on grain boundaries of Gd 2−x Ca x Zr 2 O 7−x/2 (x = 0.1), with conductivity a factor of 2.5 higher than that of Sm doped CaZrO 3 (Figs.10 and 7 b). Recently the admixture of CaZrO 3 was observed for the same composition Gd 1.9 Ca 0.1 Zr 2 O 6.95 , obtained by a hydrothermal process followed by annealing at 1500 °C for 4 h [38]. Note that, unlike SrZrO 3 and SrHfO 3 [28,34], the intergranular Gd-doped CaZrO 3 phase has higher conductivity (both the oxygen-ion and proton components) and does not limit the total conductivity of the material.…”

Section: Resultsmentioning

confidence: 99%

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Evolution of Oxygen–Ion and Proton Conductivity in Ca-Doped Ln2Zr2O7 (Ln = Sm, Gd), Located Near Pyrochlore–Fluorite Phase Boundary

et al. 2019

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Sm2−xCaxZr2O7−x/2 (x = 0, 0.05, 0.1) and Gd2−xCaxZr2O7−x/2 (x = 0.05, 0.1) mixed oxides in a pyrochlore–fluorite morphotropic phase region were prepared via the mechanical activation of oxide mixtures, followed by annealing at 1600 °C. The structure of the solid solutions was studied by X-ray diffraction and refined by the Rietveld method, water content was determined by thermogravimetry (TG), their bulk and grain-boundary conductivity was determined by impedance spectroscopy in dry and wet air (100–900 °C), and their total conductivity was measured as a function of oxygen partial pressure in the temperature range: 700–950 °C. The Sm2−xCaxZr2O7−x/2 (x = 0.05, 0.1) pyrochlore solid solutions, lying near the morphotropic phase boundary, have proton conductivity contribution both in the grain bulk and on grain boundaries below 600 °C, and pure oxygen–ion conductivity above 700 °C. The 500 °C proton conductivity contribution of Sm2−xCaxZr2O7−x/2 (x = 0.05, 0.1) is ~ 1 × 10−4 S/cm. The fluorite-like Gd2−xCaxZr2O7−x/2 (x = 0.1) solid solution has oxygen-ion bulk conductivity in entire temperature range studied, whereas proton transport contributes to its grain-boundary conductivity below 700 °C. As a result, of the morphotropic phase transition from pyrochlore Sm2−xCaxZr2O7−x/2 (x = 0.05, 0.1) to fluorite-like Gd2−xCaxZr2O7−x/2 (x = 0.05, 0.1), the bulk proton conductivity disappears and oxygen-ion conductivity decreases. The loss of bulk proton conductivity of Gd2−xCaxZr2O7−x/2 (x = 0.05, 0.1) can be associated with the fluorite structure formation. It is important to note that the degree of Ca substitution in such solid solutions (Ln2−xCax)Zr2O7−δ (Ln = Sm, Gd) is low, x < 0.1. In both series, grain-boundary conductivity usually exceeds bulk conductivity. The high grain-boundary proton conductivity of Ln2−xCaxZr2O7−x/2 (Ln = Sm, Gd; x = 0.1) is attributable to the formation of an intergranular CaZrO3-based cubic perovskite phase doped with Sm or Gd in Zr sublattice.

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Evolution of Oxygen–Ion and Proton Conductivity in Ca-Doped Ln2Zr2O7 (Ln = Sm, Gd), Located Near Pyrochlore–Fluorite Phase Boundary

et al. 2019

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“…Exosome-derived transforming growth factor-β1 contributes to NK cell suppression via a signalling cascade resulting in the downregulation of natural killer group 2 member D (NKG2D), a transmembrane receptor essential for the cytotoxicity of NK cells [ 93 ]. Incubation of neutralising antibodies targeting TGF-β with TGF-β+ AML exosomes followed by co-incubation with the NK cell line, NK-92, restored the cytotoxic activity of NK cells, illustrating exosome-derived TGF-β as a potential therapeutic target for the restoration of immune cell cytotoxicity in AML [ 94 ]. Efforts are being made by several research groups to improve current methods of CTC isolation and detection in MM.…”

Section: Bloodmentioning

confidence: 99%

Clinical Proteomics of Biofluids in Haematological Malignancies

Dunphy

O’Mahoney

Dowling

et al. 2021

IJMS

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Since the emergence of high-throughput proteomic techniques and advances in clinical technologies, there has been a steady rise in the number of cancer-associated diagnostic, prognostic, and predictive biomarkers being identified and translated into clinical use. The characterisation of biofluids has become a core objective for many proteomic researchers in order to detect disease-associated protein biomarkers in a minimally invasive manner. The proteomes of biofluids, including serum, saliva, cerebrospinal fluid, and urine, are highly dynamic with protein abundance fluctuating depending on the physiological and/or pathophysiological context. Improvements in mass-spectrometric technologies have facilitated the in-depth characterisation of biofluid proteomes which are now considered hosts of a wide array of clinically relevant biomarkers. Promising efforts are being made in the field of biomarker diagnostics for haematologic malignancies. Several serum and urine-based biomarkers such as free light chains, β-microglobulin, and lactate dehydrogenase are quantified as part of the clinical assessment of haematological malignancies. However, novel, minimally invasive proteomic markers are required to aid diagnosis and prognosis and to monitor therapeutic response and minimal residual disease. This review focuses on biofluids as a promising source of proteomic biomarkers in haematologic malignancies and a key component of future diagnostic, prognostic, and disease-monitoring applications.

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“…The pollution of poisonous gases, such as NO 2 from the burning of fuel and the exhaust from the city autos, poses a great threat to both the environment and people's health. Therefore, it is highly desired to develop fast detection techniques for air quality assessment . Semiconductor‐based gas sensors such as SnO 2 , TiO 2 , ZnO, and so on have attracted numerous attention because of the advantages of in situ detection, fast responses, low cost, long stability, etc .…”

Section: Introductionmentioning

confidence: 99%

Enhanced NO₂ Sensing Property of ZnO by Ga Doping and H₂ Activation

Zhou

Xie

Bian

et al. 2018

Physica Status Solidi (a)

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Ga‐doped ZnO nanoparticles are successfully prepared by a facile coprecipitation method and then are activated by H2 annealing. The as‐prepared ZnO powders are characterized by X‐ray diffractometer (XRD), Brunauer–Emmett–Teller (BET), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy, Raman and photoluminescence spectroscopies. Gas sensing property using NO2 as probe shows that the 1 at.% Ga‐ZnO powders activated in H2 at 540 °C showed high NO2 response of ≈50/ppm, high selectivity toward typical interferences such as ethanol, acetone, toluene, NO, SO2, C2H6, and C2H4 and high stability as measured at 200 °C. On the contrary, the pure ZnO and the Ga‐ZnO without H2 activation show far lower response, which illustrates the effect of Ga dopant activation by H2 annealing aimed for the high performance gas sensing materials.

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Alkaline-Earth Metals-Doped Pyrochlore Gd2Zr2O7 as Oxygen Conductors for Improved NO2 Sensing Performance

Cited by 39 publications

References 45 publications

Evolution of Oxygen–Ion and Proton Conductivity in Ca-Doped Ln2Zr2O7 (Ln = Sm, Gd), Located Near Pyrochlore–Fluorite Phase Boundary

Evolution of Oxygen–Ion and Proton Conductivity in Ca-Doped Ln2Zr2O7 (Ln = Sm, Gd), Located Near Pyrochlore–Fluorite Phase Boundary

Clinical Proteomics of Biofluids in Haematological Malignancies

Enhanced NO₂ Sensing Property of ZnO by Ga Doping and H₂ Activation

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Alkaline-Earth Metals-Doped Pyrochlore Gd2Zr2O7 as Oxygen Conductors for Improved NO2 Sensing Performance

Cited by 39 publications

References 45 publications

Evolution of Oxygen–Ion and Proton Conductivity in Ca-Doped Ln2Zr2O7 (Ln = Sm, Gd), Located Near Pyrochlore–Fluorite Phase Boundary

Evolution of Oxygen–Ion and Proton Conductivity in Ca-Doped Ln2Zr2O7 (Ln = Sm, Gd), Located Near Pyrochlore–Fluorite Phase Boundary

Clinical Proteomics of Biofluids in Haematological Malignancies

Enhanced NO2 Sensing Property of ZnO by Ga Doping and H2 Activation

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Enhanced NO₂ Sensing Property of ZnO by Ga Doping and H₂ Activation