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187 results on '"Jiang, Kezhu"'

3. Realizing Phase‐Pure (PEA)2FAPb2I7 Perovskite Films by Inhibiting 3D Phase Formation.

Author

Liang, Yuchao, Liu, Fangzhou, Xie, Xixi, Ma, Yingzhuang, Guan, Yan, Yu, Wenjin, Zou, Yu, Zhang, Lingling, Zhang, Xian, Zhang, Yangyang, Li, Bohan, Wu, Cuncun, Jiang, Kezhu, Xiao, Lixin, Zou, Dechun, and Zheng, Shijian

Subjects
HUMIDITY control, PEROVSKITE, 3-D films, THIN films, PHOTODETECTORS
Abstract

2D Ruddlesden–Popper (RP) layered metal‐halide perovskites have garnered significant interest due to their unique photoelectric properties and excellent stability. However, 2D perovskite films prepared via solution process generally exhibit multi‐quantum well structure with random well width distribution, which significantly impedes the carrier transportation. Herein, the synthesis of phase‐pure 2D (PEA)2FAPb2I7 (PEA = C8H11N, FA = CH4N2) perovskite thin films is reported in ambient environment achieved by suppressing the formation of the 3D perovskite phase. First, incorporation of MACl additive can effectively regulate the intermediate during crystallization, facilitating the formation of a metastable 3D MAxFA1‐xPbIyCl3‐y phase. Second, precise control of environmental humidity is employed to further inhibit the formation of α‐FAPbI3 phase. As a result, the perovskite intermediate composed of predominantly metastable 3D phase and 2D n = 2 phase is achieved, which is eventually transformed into 2D n = 2 perovskite during annealing, leading to markedly enhanced phase purity. Photoconductive‐type photodetectors based on the phase‐pure 2D RP perovskite films are fabricated, demonstrating a high detectivity of over 9.4 × 1012 Jones due to the improved carrier transportation. This study provides a comprehensive insight into the crystallization process of phase‐pure 2D perovskites. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Realizing Phase‐Pure (PEA)2FAPb2I7 Perovskite Films by Inhibiting 3D Phase Formation

Author

Liang, Yuchao, primary, Liu, Fangzhou, additional, Xie, Xixi, additional, Ma, Yingzhuang, additional, Guan, Yan, additional, Yu, Wenjin, additional, Zou, Yu, additional, Zhang, Lingling, additional, Zhang, Xian, additional, Zhang, Yangyang, additional, Li, Bohan, additional, Wu, Cuncun, additional, Jiang, Kezhu, additional, Xiao, Lixin, additional, Zou, Dechun, additional, and Zheng, Shijian, additional

Published
2024
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6. 3D Noble-Metal Nanostructures Approaching Atomic Efficiency and Atomic Density Limits

Author

Liu, Shangheng, Huang, Wei-Hsiang, Meng, Shuang, Jiang, Kezhu, Han, Jiajia, Zhang, Qiaobao, Hu, Zhiwei, Pao, Chih-Wen, Geng, Hongbo, Huang, Xuan, Zhan, Changhong, Yun, Qinbai, Xu, Yong, Huang, Xiaoqing, Liu, Shangheng, Huang, Wei-Hsiang, Meng, Shuang, Jiang, Kezhu, Han, Jiajia, Zhang, Qiaobao, Hu, Zhiwei, Pao, Chih-Wen, Geng, Hongbo, Huang, Xuan, Zhan, Changhong, Yun, Qinbai, Xu, Yong, and Huang, Xiaoqing

Abstract

Noble metals have been widely used in catalysis, however, the scarcity and high cost of noble metal motivate researchers to balance the atomic efficiency and atomic density, which is formidably challenging. This article proposes a robust strategy for fabricating 3D amorphous noble metal-based oxides with simultaneous enhancement on atomic efficiency and density with the assistance of atomic channels, where the atomic utilization increases from 18.2% to 59.4%. The unique properties of amorphous bimetallic oxides and formation of atomic channels have been evidenced by detailed experimental characterizations and theoretical simulations. Moreover, the universality of the current strategy is validated by other binary oxides. When Cu2IrOx with atomic channels (Cu2IrOx-AE) is used as catalyst for oxygen evolution reaction (OER), the mass activity and turnover frequency value of Cu2IrOx-AE are 1–2 orders of magnitude higher than CuO/IrO2 and Cu2IrOx without atomic channels, largely outperforming the reported OER catalysts. Theoretical calculations reveal that the formation of atomic channels leads to various Ir sites, on which the proton of adsorbed *OH can transfer to adjacent O atoms of [IrO6]. This work may attract immediate interest of researchers in material science, chemistry, catalysis, and beyond. © 2024 Wiley-VCH GmbH.

Published
2024

7. 3D Noble‐Metal Nanostructures Approaching Atomic Efficiency and Atomic Density Limits

Author

Liu, Shangheng, primary, Huang, Wei‐Hsiang, additional, Meng, Shuang, additional, Jiang, Kezhu, additional, Han, Jiajia, additional, Zhang, Qiaobao, additional, Hu, Zhiwei, additional, Pao, Chih‐Wen, additional, Geng, Hongbo, additional, Huang, Xuan, additional, Zhan, Changhong, additional, Yun, Qinbai, additional, Xu, Yong, additional, and Huang, Xiaoqing, additional

Published
2024
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20. Lattice‐Strained Metallic Aerogels as Efficient and Anti‐Poisoning Electrocatalysts for Oxygen Reduction Reaction.

Author

Fu, Hui, Huang, Honggang, Chen, Yao, Jiang, Kezhu, Lai, Feili, Chen, Cun, Zhang, Zhe, Li, Hanjun, Zhang, Nan, and Liu, Tianxi

Subjects
OXYGEN reduction, AEROGELS, X-ray photoelectron spectroscopy, ELECTROCATALYSTS, REFLECTANCE spectroscopy, RADIOCARBON dating
Abstract

Lattice strain engineering optimizes the interaction between the catalytic surface and adsorbed molecules. This is done by adjusting the electron and geometric structure of the metal site to achieve high electrochemical performance, but, to date, it has been rarely reported on anti‐poisoned oxygen reduction reaction (ORR). Herein, lattice‐strained Pd@PdBiCo quasi core‐shell metallic aerogels (MAs) were designed by "one‐pot and two‐step" method for anti‐poisoned ORR. Pd@PdBiCo MAs/C maintain their original activity (1.034 A mgPd−1) in electrolytes with CH3OH and CO at 0.85 V vs. reversible hydrogen electrode (RHE), outperforming the commercial Pd/C (0.156 A mgPd−1), Pd MAs/C (0.351 A mgPd−1), and PdBiCo MAs/C (0.227 A mgPd−1). Moreover, Pd@PdBiCo MAs/C also show high stability and anti‐poisoning with negligible activity decay after 8000 cycles in 0.1 m KOH+0.3 m CH3OH. These results of X‐ray photoelectron spectroscopy, CO stripping, and diffuses reflectance FTIR spectroscopy reveal that the tensile strain and strong interaction between different elements of Pd@PdBiCo MAs/C effectively optimize the electronic structure to promote O2 adsorption and activation, while suppressing CH3OH oxidation and CO adsorption, leading to high ORR activity and anti‐poisoning property. This work inspires the rational design of MAs in fuel cells and beyond. [ABSTRACT FROM AUTHOR]

Published
2024
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22. Mo-doped PdCu nanoparticles as high-performance catalysts for oxygen reduction reactions.

Author

Kang, Kailu, Hu, Xing, Zhang, Pei, Zhang, Yangyang, Zhu, Shan, Lei, Kaixiang, Jiang, Kezhu, and Zheng, Shijian

Subjects
OXYGEN reduction, BINARY metallic systems, CATALYSTS, CATALYTIC activity, COPPER, NANOPARTICLES
Abstract

The instability of palladium-based binary alloys hinders their wide application in the oxygen reduction processes. Here, we prepared Mo-doped PdCu nanoparticles with controllable dopant content and valence. Further research has revealed that Mo, particularly Mo5+, may effectively suppress the oxidation of Pd and Cu, optimize the oxygen binding of Pd, and increase catalytic activity and stability. In particular, Mo-PdCu-1/C with the highest Mo5+ content shows the best oxygen reduction reaction (ORR) mass activity (1.20 A mg−1Pd), which is 4.8 times higher than that of PdCu/C. It also exhibits outstanding stability, retaining 80.8% of the original mass activity after 20 000 cycles. This study clearly explains the mechanism by which Mo doping affects the performance and provides a reference for further optimization of catalyst performance for fuel cell industrialization. [ABSTRACT FROM AUTHOR]

Published
2023
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28. An ultrafast rechargeable lithium metal battery

Author

ISHIDA, Masayoshi, Li, Xiang, Guo, Shaohua, Deng, Han, Jiang, KeZhu, Qiao, Yu, and Zhou, Haoshen

Abstract

Rechargeable lithium metal batteries have been regarded as one of the most attractive high-energy-density batteries due to their large specific capacity and the lowest reduction potential of metallic lithium. However, the uncontrollable Li dendrite growth and the resulting unstable interfaces during repeated Li plating/stripping lead to severe safety issues and a short cycle life, which are aggravated especially at a high current density. Herein, we present an organic/inorganic composite protective layer via pretreating the lithium metal in an Mn(NO3)2-containing carbonate electrolyte, not only enabling stable lithium deposition and formation with a prolonged cycle life, but also providing a record high rate of 20 mA cm−2 with a minimized overpotential of 60 mV in a symmetric lithium cell. Results indicate that such an artificial protective film could effectively prolong the cycle life of Li|Cu cells, and greatly improve the comprehensive electrochemical performance of Li|LiMn2O4 cells. The pretreated-Li|LiMn2O4 cells show an outstanding cycling performance with 83% capacity retention over 200 cycles at a high rate of 2C and a high temperature of 55 °C, and exhibit robust recovery capabilities with a high capacity and coulombic efficiency after the cycles at 10C. These findings highlight the significance of a protective layer in stabilizing a Li metal anode and pave a new way for designing high-energy batteries for practical utilization.

Published
2018

30. Na+/vacancy disordered manganese-based oxide cathode with ultralow strain enabled by tuning charge distribution.

Author

Li, Siyuan, Zhang, Yangyang, Lei, Kaixiang, Yang, Qian, Liu, Zheng, Jiang, Kezhu, Li, Fujun, Lu, Qiongqiong, Mikhailova, Daria, and Zheng, Shijian

Abstract

Layered manganese-based oxide cathodes have attracted extensive attention in sodium-ion batteries (SIBs) due to their low cost and high volumetric energy density. However, Na+/vacancy ordering destabilizes the host structure and retards Na+ diffusion. Herein, we report that this issue can be solved by introducing the highly electropositive Sn4+ to tune charge distribution and then reduce electron delocalization as well as in-plane Na+–Na+ electrostatic repulsions. The disordered Na vacancy arrangement and suppressed P′2 ↔ P2 phase transition enable P′2-Na0.67Mn0.95Sn0.05O2 with fast Na+ migration and ultralow strain (<1%) during cycles. Thus, high reversible capacity of 131.2 mA h g−1 and coulombic efficiency of 99.77% are achieved at 50 mA g−1 after 200 cycles. Besides, based on a low reaction energy barrier, the electrode exhibits high Na-storage activity in a wide temperature range of −20 to 70 °C. These observations provide an effective strategy for designing high-performance cathode materials in rechargeable SIBs and beyond. [ABSTRACT FROM AUTHOR]

Published
2022
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47. Improving the structural and cyclic stabilities of P2-type Na0.67MnO2 cathode material via Cu and Ti co-substitution for sodium ion batteries.

Author

Zhang, Xueping, Qiu, Feilong, Jiang, Kezhu, He, Ping, Han, Min, Guo, Shaohua, and Zhou, Haoshen

Subjects
SODIUM ions, CHEMICAL stability, ELECTRIC batteries, MATERIALS
Abstract

An air-stable Na0.67Mn0.7Cu0.15Ti0.15O2 (NMCT) has been synthesized using a solid-state method. It displays a reversible capacity of 170 mA h g−1 and a capacity retention of 82.5% after 300 cycles. NMCT also exhibits good structural stability upon electrochemical de/intercalation processes as observed by operando XRD. And the result shows that the unit-cell volume change of NMCT during the whole process of Na+ de/intercalation is only 3.2%. These data indicate that NMCT is a promising cathode material for sodium ion batteries (SIBs). [ABSTRACT FROM AUTHOR]

Published
2020
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