Browsing by Author "Gao, J"

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    The formation of defect-pairs for highly efficient visible-light catalysts
    (Wiley, 2017-01-23) Sun, QB; Cortie, DL; Zhang, SY; Frankcombe, TJ; She, GW; Gao, J; Sheppard, LR; Hu, WB; Chen, H; Zhuo, SJ; Chen, DH; Withers, RL; McIntyre, GJ; Yu, DH; Shi, WS; Liu, Y
    Highly efficient visible-light catalysts are achieved through forming defect-pairs in TiO2 nanocrystals. This study therefore proposes that fine-tuning the chemical scheme consisting of charge-compensated defect-pairs in balanced concentrations is a key missing step for realizing outstanding photocatalytic performance. This research benefits photocatalytic applications and also provides new insight into the significance of defect chemistry for functionalizing materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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    Highly efficient visible light catalysts driven by Ti3+-VO-2Ti4+-N3− defect clusters
    (Wiley, 2018-10-13) Sun, QB; Zhang, SY; Cortie, DL; Langley, J; Cox, N; Frankcombe, TJ; Gao, J; Chen, H; Withers, RL; Kremer, F; Yu, DH; Brink, F; Shi, WS; Liu, Y
    Local defect structures play significant roles on material properties, but they are seriously neglected in the design, synthesis, and development of highly efficient TiO2-based visible light catalysts (VLCs). Here, we take anatase TiO2 nanocrystals that contain (Ti3+, N3−) ions and have the complicated chemical formula of (Ti1-x4+Tix3+)(O2-2-y-zNy3-□z) as an example, and point out that the formation of Ti3+-VO-2Ti4+-N3− local defect clusters is a key missing step for significantly enhancing VLC properties of host TiO2 nanocrystals. Experimental and theoretical investigations also demonstrate the emergent behaviors of these intentionally introduced defect clusters for developing highly efficient VLCs. This research thus not only provides highly efficient visible light catalysts for various practical applications but also addresses the significance of local defect structures on modifying material properties. © 2019 Wiley-VCH Verlag GmbH & Co.
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    Highly efficient visible light catalysts driven by Ti3+‐VO‐2Ti4+‐N3− defect clusters
    (Wiley, 2018-10-13) Sun, QB; Zhang, SY; Cortie, DL; Langley, J; Cox, N; Frankcombe, TJ; Gao, J; Chen, H; Withers, RL; Kremer, F; Yu, DH; Brink, F; Shi, WS; Liu, Y
    Local defect structures play significant roles on material properties, but they are seriously neglected in the design, synthesis, and development of highly efficient TiO2‐based visible light catalysts (VLCs). Here, we take anatase TiO2 nanocrystals that contain (Ti3+, N3−) ions and have the complicated chemical formula of ()(□z) as an example, and point out that the formation of Ti3+‐VO‐2Ti4+‐N3− local defect clusters is a key missing step for significantly enhancing VLC properties of host TiO2 nanocrystals. Experimental and theoretical investigations also demonstrate the emergent behaviors of these intentionally introduced defect clusters for developing highly efficient VLCs. This research thus not only provides highly efficient visible light catalysts for various practical applications but also addresses the significance of local defect structures on modifying material properties. © 1999-2024 John Wiley & Sons, Inc or related companies.
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    Practical high-performance lead-free piezoelectrics: structural flexibility beyond utilizing multiphase coexistence
    (Oxford University Press, 2020-02-01) Liu, Q; Zhang, Y; Gao, J; Zhou, Z; Yang, D; Lee, KY; Studer, AJ; Hinterstein, M; Wang, K; Zhang, X; Li, L; Li, JF
    Due to growing concern for the environment and human health, searching for high-performance lead-free piezoceramics has been a hot topic of scientific and industrial research. Despite the significant progress achieved toward enhancing piezoelectricity, further efforts should be devoted to the synergistic improvement of piezoelectricity and its thermal stability. This study provides new insight into these topics. A new KNN-based lead-free ceramic material is presented, which features a large piezoelectric coefficient (d33) exceeding 500 pC/N and a high Curie temperature (Tc) of  ∼200°C. The superior piezoelectric response strongly relies on the increased composition-induced structural flexibility due to lattice softening and decreased unit cell distortion. In contrast to piezoelectricity anomalies induced via polymorphic transition, this piezoelectricity enhancement is effective within a broad temperature range rather than a specific small range. In particular, a hierarchical domain architecture composed of nano-sized domains along the submicron domains was detected in this material system, which further contributes to the high piezoelectricity. © C TheAuthor(s) 2019. Published by OxfordUniversity Press on behalf of China Science Publishing&Media Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Media Ltd. (Science Press).
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    Spectroscopic studies and crystal structures of double thorium(IV) oxalates with sodium ions
    (John Wiley and Sons, 2013-11-08) Zhang, YJ; Bhadbhade, MM; Karatchevtseva, I; Gao, J; Price, JR; Lumpkin, GR
    Two new double thorium oxalates with sodium ions have been prepared and characterized by using scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS), Raman spectroscopy and single-crystal X-ray diffraction. The crystal structure of Na4[Th(C2O4)4]·5.5H2O (1) contains infinite chains, [Th(μ2-C2O4)2(C2O4)3]n4n–, with three terminating bidentate and two bridging tetradentate oxalate ligands. The crystal structure of Na10[Th2(C2O4)9]·15H2O (2) comprises unique dimers, [Th2(μ2-C2O4)(C2O4)8]10–, with Th atoms being coordinated by five oxalato ligands, four terminating bidentate and one bridging tetradentate. The structure is the first dimer of tetravalent actinide oxalato complexes. The spectroscopic results are in good agreement with the crystal structures. © 2013, Wiley-Vch Verlag.