NANOTECHNOLOGY
·
2020
·Vol. 31
·期 19
·194001
·
IF 3.551
Bo Wang,Xin Huang,Xiao-Nan Zhou,Qiang Zhi,Liu-Cheng Hao,Zi-Xuan Li,Shan Zhao,Bao-Qiang Hou,Jian-Feng Yang,Kozo Ishizaki
One-dimensional Si3N4 nanostructures are desirable for constructing nanoscale electric and optoelectronic devices due to their peculiar morphologies. Herein, a facile and environmentally friendly catalyst-free method is proposed to synthesize ultra-long single crystal α-Si3N4 nanobelts via carbothermal nitridation of carbon nanotubes at 1750 °C. The obtained α-Si3N4 nanobelts with a flat surface (thickness of ∼150 nm, length of several millimeters) exhibited an extremely high aspect ratio, perfect crystal structure, and high specific surface area of 7.34–10.09 m2 g−1. In addition, the width was increased from approximately 80 nm to 8 μm by increasing the holding time from 1 to 3 h. The nanobelt formation was governed by the vapor–solid (VS) reaction between SiO vapor, N2 and carbon nanotubes, and the vapor–vapor reaction between SiO, CO and N2. The former was responsible for the initial nucleation and successive base-growth of α-Si3N4 nanotubes. The latter additionally contributed to the nanorod and subsequent proto-nanobelt formation and to the growth of the nanobelts. During high-temperature annealing at 1750 °C, the original Si3N4 nanotubes gradually transformed into nanorods, and, finally, nanobelts with stable shapes as a result of surface energy minimization.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 42
·21143-21148
·
IF 9.931
Long Luo,Yulong Zhang,Nianyao Chai,Xi Deng,Jie Zhong,Fuzhi Huang,Yong Peng,Zhiliang Ku,Yi-Bing Cheng
Large-area, highly uniform CsxFA1−xPbI3−yBry mixed cation perovskite films were prepared by a facile vapor–solid reaction method. In this method, CsBr and PbI2 were first deposited via thermal evaporation, and then exposed to FAI/FACl vapor to form the CsxFA1−xPbI3−yBry perovskite. With the incorporation of CsBr, the crystallinity of the FAPbI3 perovskite could be significantly improved. Meanwhile, the FACl vapor could accelerate the growth rate of the CsxFA1−xPbI3−yBry perovskite in the vapor–solid reaction process. By optimizing the content of Cs and the ratio of FACl/FAI, we obtained high quality, pin-hole free Cs0.24FA0.76PbI3−yBry films. Based on these films, the small sized perovskite solar cells (PSCs) reached a champion power conversion efficiency (PCE) of 17.29%. Without encapsulation, the device with the Cs0.24FA0.76PbI3−yBry perovskite showed much better moisture and thermal stability in comparison to that with the pristine FAPbI3 perovskite. Furthermore, we also fabricated PSC modules with a size of 8 × 8 cm2 and achieved a PCE of 12.24%, indicating that such a vapor–solid reaction method has a certain superiority in the manufacture of large-scale PSCs.
研究领域:
材料科学
·
太阳能技术
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
·
2025
·Vol. 11
·期 9
·
IF 12.5
Xinshui Zhang,Yihang Yang,Ruixin Hao,Yue Zhang,Xiangchen Hu,Hongsheng Shi,Zheyu Yang,Jiameng Yu,Xin Chen,Chang Zhang,Na Yu,Tianyi Gao,Ran Wei,Zhenbo Zhang,Yi Yu,Wei Liu
Textured ceramics with anisotropic ionic conductivity are poised to establish superior ion transport pathways in solid-state electrochemical devices. However, their preparation methods remain a challenge. Here, we develop a gas-solid reactive sintering technique that successfully fabricates a variety of textured lithium ceramics, including electrolyte and electrode materials. These textured lithium ceramic electrolytes exhibit large columnar grains perpendicular to the surface. The textured electrodes indicate an out-of-plane crystallographic texture. As a result, the Li-ion transport pathways across the grain boundary plane are avoided in the textured lithium ceramic with low tortuosity, resulting in great ionic conductivity enhancement by 42 times compared to its traditional equiaxed counterpart. In addition, both Monte Carlo simulation and finite element analysis support the experimental results. This innovative gas-solid reactive sintering technique can extend to prepare various structured and functional ceramics with tailored structures and properties.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 33
·期 10
·105601
·
IF 3.874
Li Lin,Xing Du,Junjie Wang,Hui Chen,Xuan He,Wei Fang,Yang Li,Zhen Chen,Lei Zhao
Two-dimensional (2D) cobalt zeolitic imidazolate frameworks (ZIF-67) have attracted significant research interests to synthesize cobalt and nitrogen co-doped carbon-based (Co–N–C) catalyst for oxygen reduction reaction (ORR). However, most of the current synthetic approaches of 2D ZIF-67 are energy-intensive, environmentally hazardous and low-yield. Herein, a feasible and efficient 'morphology-retaining method via a high-pressure vapor-solid reaction' are reported to synthesize 2D ZIF-67 nanosheets by using 2D cobalt carbonate hydroxide template. In the strategy, the high-pressure vapor caused by sublimation of 2-Melm and the pores formed from effusion of CO2 during transformation ensure the complete transformation from 2D template to 2D ZIF-67. The corresponding 2D Co–N–C catalyst exhibits comparable ORR electrocatalytic activity and better stability than Pt/C in alkaline media. The present method is expected to offer a feasible and universal way to efficiently synthesize 2D M–N–C catalysts.
研究领域:
材料科学
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电化学
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COMPOSITES PART B-ENGINEERING
·
2025
·
IF 14.2
Junjie Zhou,Yike Zhang,Xinyu Wang,Yanan Yang,Xin Wu,Jin Hu,Long Xia
Impedance mismatch and high-temperature oxidation are two main factors that limit the practical application of carbon-based absorbing materials. Although micro/nano-structured composites have been explored to alleviate these issues, they often suffer from dispersion instability and structural fragility. In this work, a coaxial composite fiber microwave absorber (Al 4 C 3 /Al 2 O 3 @C f ) is fabricated using carbon fiber (C f ) as a template and conductive core, with an Al 4 C 3 /Al 2 O 3 ceramic shell grown in situ via a vapor–solid reaction. Compared to pristine C f , which exhibits negligible absorption, the optimized composite achieves a minimum reflection loss of −49.27 dB, attributed to interfacial polarization and a built-in capacitor-like structure. Meanwhile, the material also features excellent oxidation resistance and thermal insulation (0.0567 W m −1 K −1 at 100 °C). This study presents a structurally controllable, thermally robust absorber design that overcomes key limitations of traditional carbon-based materials, offering a promising solution for next-generation electromagnetic protection in aerospace and harsh environments.
研究领域:
材料科学
·
电磁吸收
·
热绝缘
·
陶瓷复合材料
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）