Materials
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2019
·Vol. 12
·期 9
·1501
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IF 2.972
Hongdan Zhang,Ludan Zhu,Jun Cheng,Long Chen,Chuanqi Liu,Shuanglong Yuan
In recent years, all-inorganic lead-halide perovskites have received extensive attention due to their many advantages, but their poor stability and high toxicity are two major problems. In this paper, a low toxicity and stable Cs2SnCl6double perovskite crystals were prepared by aqueous phase precipitation method using SnCl2as precursor. By the XRD, ICP-AES, XPS, photoluminescence and absorption spectra, the fluorescence decay curve, the structure and photoluminescence characteristics of Ce3+-doped and undoped samples have been investigated in detail. The results show that the photoluminescence originates from defects. [SnSn4+2++VCl] defect complex in the crystal is formed by Sn2+substituting Sn4+. The number of defects formed by Sn2+in the crystal decreases with Ce3+content increases. Within a certain number of defects, the crystal luminescence is enhanced with the number of [SnSn4+2++VCl] decreased. When Ce3+is incorporated into the crystals, the defects of [Ce3+Sn4++VCl] and [SnSn4+2++VCl] were formed and the crystal show the strongest emission. This provides a route to enhance the photoluminescence of Cs2SnCl6double perovskite crystals.Keywords:lead-free perovskite;Cs2SnCl6;doping;photoluminescence
研究领域:
材料科学
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光电
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固体物理
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产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
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2024
·
IF 14
Baofei Sun,Wei Chen,Yanyi Huang,Daofu Wu,Heng Luo,Faguang Kuang,Hongmei Ran,Yichen Liu,Liqin Gao,Jinchen Zhou,Bo Gao,Qiang Huang,Xiaosheng Tang
Metal halide perovskites (MHP) are potential candidates for the photocatalytic reduction of CO 2 due to their long photogenerated carrier lifetime and charge diffusion length. However, the conventional long-chain ligand impedes the adsorption and activation of CO 2 molecules in practical applications. Here, a ligand modulation technology is employed to enhance the photocatalytic CO 2 reduction activity of lead-free Cs 2 AgInCl 6 microcrystals (MCs). The Cs 2 AgInCl 6 MCs passivated by Oleic acid (OLA) and Octanoic acid (OCA) are used for photocatalytic CO 2 reduction. The results show that the surface defects and electronic properties of Cs 2 AgInCl 6 MCs can be adjusted through ligand modulation. Compared with the OLA-Cs 2 AgInCl 6 , the OCA-Cs 2 AgInCl 6 catalyst demonstrated a significant improvement in the catalytic yield of CO and CH 4 . The CO and CH 4 catalytic yields of OCA-Cs 2 AgInCl 6 reached 171.88 and 34.15 µmol g −1 h −1 which were 2.03 and 12.98 times higher than those of OLA- Cs 2 AgInCl 6 , and the total electron consumption rate of OCA-Cs 2 AgInCl 6 was 615.2 µmol g −1 h −1 which was 3.25 times higher than that of OLA-Cs 2 AgInCl 6 . Furthermore, in situ diffuse reflectance infrared Fourier transform spectra revealed the enhancement of photocatalytic activity in Cs 2 AgInCl 6 MCs induced by ligand modulation. This study illustrates the potential of lead-free Cs 2 AgInCl 6 MCs for efficient photocatalytic CO 2 reduction and provides a ligand modulation strategy for the active promotion of MHP photocatalysts.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Crystals
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2019
·Vol. 9
·期 5
·258
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IF 2.061
Hongdan Zhang,Ludan Zhu,Jun Cheng,Long Chen,Chuanqi Liu,Shuanglong Yuan
The Cs2SnX6perovskites have attracted much attention due to excellent optoelectronic properties and high stability. In the present work, we have focused on the morphology control and photoluminescence characteristics of the Cs2SnCl6perovskite crystals. The synthesis process of the Cs2SnCl6crystals includes two stages composed of the formation of initial crystals and the growth of Cs2SnCl6; the later originated from the oxidization of CsSnCl3. This process has been confirmed by Scanning electron microscope (SEM) and X-rays diffraction (XRD). By controlling the concentration of the initial reactants and hydrochloric acid in the solution to change the supersaturation of the solution, different crystal morphologies, such as truncated octahedron, octahedron, hexapod, quasi-sphere, have been obtained. In relatively a low supersaturation solution, the amount of growth units dominates the crystal growth process to obtain the hexapod and self-assembly crystals. In contrast, in relatively high supersaturation solution, nucleation predominates to yield small size truncated octahedrons and near-spherical Cs2SnCl6crystals. The synthesized Cs2SnCl6crystals have shown a wide emission band peaking at 450 nm with full width at half maximum (FWHM) 63 nm due to the defects introduced by Sn2+. The photoluminescence intensities of crystals synthesized at various conditions exhibited considerable difference, which was about 60 times between the highest and the lowest.Keywords:lead-free perovskite;Cs2SnCl6;crystal growth;photoluminescence
研究领域:
材料科学
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光学
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产品关联
DOI
高影响因子
Journal of Materiomics
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2024
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IF 8.4
Yingzhi Meng,Silin Tang,Zhaojie Wang,Xiang Niu,Hongfang Zhang,Dingyuan Wang,Yisong Bai,Biaolin Peng,Sheng-Guo Lu,Qingqing Ke,Laijun Liu
The electrocaloric effect (ECE) offers a pathway to environmentally sustainable and easily miniaturized refrigeration technology, positioning it as a front-runner for the next generation of solid-state cooling solutions. This research unveils a remarkable ECE in a finely tuned (Ba 0.86 Ca 0.14 ) 0.98 La 0.02 Ti 0.92 Sn 0.08 O 3 ceramic, exhibiting a temperature shift (Δ T ) of 1.6 K across more than 85% of the maximum Δ T (Δ T max ) and spanning an exceptionally wide operational range of 92 K. Our investigation on dielectric responses and ferroelectric polarization-electric field ( P–E ) loops suggests that the broad operational scope results from the fragmentation of extended ferroelectric domains into smaller domains and polar nano-regions (PNRs) supported by PFM analysis. Furthermore, the introduction of La enhances spontaneous polarization by significantly extending the maximum electric field that can be applied, facilitating high-performance ECE at ambient temperature. This study positions BaTiO 3 -based lead-free ceramic as a sustainable alternative for addressing the cooling demands of modern electronic components, marking a significant stride toward next-generation solid-state refrigeration.
研究领域:
材料科学
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固态制冷技术
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2021
·Vol. 32
·期 7
·9032-9043
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IF 2.478
Liu Yunyi,Pan Yongqi,Bai Xudong,Wang Jinchuan,He Caiwang,Xu Zunping,Chen Yi
A conventional ceramic preparation method was used to fabricate the newly designed ternary (K,Na)NbO 3 -based lead-free ceramics, which have the general formula of (0.97- x )K 0.40 Na 0.60 Nb 0.95 Sb 0.05 O 3 –0.03Bi 0.5 K 0.5 HfO 3 – x SrZrO 3 . An X-ray diffraction analysis, together with dielectric-temperature measurements, was performed for determining their phase structures. The crystal structure was found to transition from a rhombohedral-orthogonal phase coexistence to a three-phase coexistence of rhombohedral-orthogonal-tetragonal phases with the increase in SrZrO 3 concentration, and then to a rhombohedral-tetragonal phase coexistence, and finally to a single rhombohedral phase. Near the three-phase coexistence zone, the ceramics exhibit an obviously enhanced electrical activity, with an electromechanical coupling coefficient k p = 0.364 and a piezoelectric constant d 33 = 280 pC/N. Through a microstructure analysis, a slightly excessive amount of SrZrO 3 was found to result in an inhibition for the grain growth of the studied ceramics. These results show that incorporating SrZrO 3 into ternary (K,Na)NbO 3 -based ceramics is still an effective means of constructing phase boundaries and improving the electromechanical properties.
研究领域:
材料科学
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物理学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2022
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IF 10.383
Jiajun Ma,Donghai Zhang,Fei Ying,Xiongjie Li,Ling Li,Shun Guo,Yu Huan,Ji Zhang,Jing Wang,Shan-Tao Zhang
Dielectric capacitors have attracted growing attention because of their important applications in advanced high power and/or pulsed power electronic devices. Nevertheless, the synergistic enhancement of recoverable energy storage density (Wrec > 10 J/cm3) and efficiency (η > 80%) is still a great challenge for lead-free dielectric bulk ceramics. Herein, by introducing complex perovskite compound (Bi0.9Na0.1)(Fe0.8Ti0.2)O3 with a smaller tolerance factor into an NaNbO3 matrix (NN-BNFT), we have achieved and explored stable relaxor antiferroelectric ceramics with enhanced relaxor behavior. Of particular importance is the composition of 0.88NN-0.12BNFT, which exhibits a large electric breakdown strength Eb of 87.3 kV/mm, an ultrahigh Wrec of 12.7 J/cm3, and a high efficiency η of 82.5%, as well as excellent thermal reliability and an ultrafast discharge speed, resulting from the dense microstructure, the moderate dielectric constant, the reduced grain size, the dielectric loss, and the sample thickness. The outstanding energy storage properties of NN-BNFT display great promise in advanced dielectric capacitors for energy storage applications.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
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2022
·Vol. 27
·期 23
·8259
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IF 4.927
Ping Gao,Suwen Cheng,Jiaxin Liu,Junjie Li,Yanyan Guo,Zhengtao Deng,Tianshi Qin,Aifei Wang
Lead-free all-inorganic halide materials with different Mn2+-based crystal structures (Cs3MnBr5and CsMnBr3) were obtained using a convenient synthetic method. Cs3MnBr5had a bright green emission (522 nm), with a unique single-exponential lifetime (τavg= 236 µs) and a high photoluminescence quantum yield (82 ± 5%). A red emission was observed in the case of the CsMnBr3structure with a two-exponential fluorescence decay curve, and the lifetime was 1.418 µs (93%) and 18.328 µs (7%), respectively. By a judicious tuning of the synthetic conditions, a mixed phase of Cs3MnBr5/CsMnBr3was also produced that emitted white light, covering almost the entire visible spectrum. White-light-emitting diodes (WLEDs) with color coordinates (0.4269, 0.4955), a color temperature of (3773 K), and a color rendering index (68) were then fabricated using the as-prepared powder of mixed phases of Cs3MnBr5/CsMnBr3with a commercial UV LED chip (365 nm).Keywords:perovskite;Cs3MnBr5;manganese halide;phosphor;white LEDs
研究领域:
材料科学
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光学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2016
·
IF 3.014
Huajun Sun,Saihong Duan,Xiaofang Liu,Dawei Wang,Huiting Sui
Lead-free Ba 0.98 Ca 0.02 Zr 0.02 Ti 0.98 O 3 -xmol% MnO 2 (BCZT-xMn) (x = 0.1, 0.2, 0.3, 0.4, 0.5) ceramics were prepared by conventional solid-state reaction method and the effects of MnO 2 doping content and sintering temperature on microstructure and electrical properties of BCZT ceramics were studied. The ceramics samples with all MnO 2 doping contents exhibit pure perovskite structure and similar Curie temperature of approximately 120 °C. Among all, the sample with 0.3 mol. % MnO 2 doping content sintered at 1400 °C exhibits improved ferroelectricity with a relatively high remnant polarization ( P r ) and low coercive electric field ( E c ) of 15.7 μC/cm 2 and 180 V/mm, respectively, which can be attributed to the fact that an appropriate doping content of MnO 2 does favor to the grain growth, with the favorable effect on domain motion. Accordingly, excellent piezoelectric property with piezoelectric coefficient ( d 33 ) of 308 pC/N can be obtained. Besides, the sample shows a relatively low dielectric loss (tanδ) of 1.04%. As a result, the BCZT-xMn ceramic exhibits the potential to be used in memory and transformer applications.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2022
·
IF 5.532
Feng Luo,Zhimin Li,Jiyuan Chen,Yuanshui Liu,Linzhuang Xing,Yangxi Yan,Yue Hao
Ecologically sustainable hard type piezoelectric ceramics are highly demanded for high power transducer applications in replacing lead-based piezoelectric ceramics. In this study, MnO was proposed as acceptor dopant to modify the electric properties of 0.75BiFeO 3 -0.25BaTiO 3 piezoelectric ceramics. Results showed that MnO doping reduced the lattice distortion of rhombohedral phase and facilitated the formation of pseudo cubic phase of 0.75BiFeO 3 -0.25BaTiO 3 system. Moreover, it caused the diversity of domain morphology and reduced the domain size as well. XPS analysis indicated that Mn 2+ ions suppressed the transition from Fe 3+ ions to Fe 2+ ions and gave rise to the increase of oxygen vacancies . Accordingly, the introduction of MnO synergistically increases the d 33 , K p , and Q m and lowers the tan δ of 0.75BiFeO 3 -0.25BaTiO 3 ceramics. The abnormal enhancement in hard type properties is ascribed mainly to the increase of extrinsic contribution rather than the pinning effect arising from oxygen vacancies. Finally, based on an optimal 0.75Bi(Fe 0.985 Mn 0.015 )O 3 -0.25BaTiO 3 system, an atomizer prototype was fabricated. The remarkable atomization effect suggests a competitive potential of 0.75BF-0.25BT ceramic for transducer application.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 17
·5881
·
IF 3.748
Yuleng Jiang,Xiang Niu,Wei Liang,Xiaodong Jian,Hongwei Shi,Feng Li,Yang Zhang,Ting Wang,Weiping Gong,Xiaobo Zhao,Yingbang Yao,Tao Tao,Bo Liang,Shengguo Lu
Owing to the high power density, excellent operational stability and fast charge/discharge rate, and environmental friendliness, the lead-free Na0.5Bi0.5TiO3(NBT)-based relaxor ferroelectrics exhibit great potential in pulsed power capacitors. Herein, novel lead-free (1−x)(0.7Na0.5Bi0.5TiO3-0.3Sr0.7Bi0.2TiO3)-xBi(Mg0.5Zr0.5)O3(NBT-SBT-xBMZ) relaxor ferroelectric ceramics were successfully fabricated using a solid-state reaction method and designed via compositional tailoring. The microstructure, dielectric properties, ferroelectric properties, and energy storage performance were investigated. The results indicate that appropriate Bi(Mg0.5Zr0.5)O3content can effectively enhance the relaxor ferroelectric characteristics and improve the dielectric breakdown strength by forming fine grain sizes and diminishing oxygen vacancy concentrations. Therefore, the optimalWrecof 6.75 J/cm3and aηof 79.44% were simultaneously obtained in NBT-SBT-0.15BMZ at 20 °C and 385 kV/cm. Meanwhile, thermal stability (20–180 °C) and frequency stability (1–200 Hz) associated with the ultrafast discharge time of ~49.1 ns were also procured in the same composition, providing a promising material system for applications in power pulse devices.Keywords:Na0.5Bi0.5TiO3;lead-free;relaxor ferroelectrics;compositional tailoring;energy storage
研究领域:
材料科学
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能源技术
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2021
·
IF 9.229
Bowei Xun,Aizhen Song,Jingru Yu,Yang Yin,Jing-Feng Li,Bo-Ping Zhang
BiFeO3-BaTiO3 is a promising high-temperature piezoelectric ceramic that possesses both good electromechanical properties and a Curie temperature (TC). Here, the piezoelectric charge constants (d33) and strain coefficients (d*33) of (1 – x)BiFeO3-xBaTiO3 (BF-xBT; 0.20 ≤ x ≤ 0.50) lead-free piezoelectrics were investigated at room temperature. The results showed a maximum d33 of 225 pC/N in the BF-0.30BT ceramic and a maximum d*33 of 405 pm/V in the BF-0.35BT ceramic, with TCs of 503 and 415 °C, respectively. To better understand the performance enhancement mechanisms, a phase diagram was established using the results of XRD, piezoresponse force microscopy, TEM, and electrical property measurements. The superb d33 of the BF-0.30BT ceramic arose because of its location in the optimum point in the morphotropic phase boundary, low oxygen vacancy (VO··) concentration, and domain heterogeneity. The superior d*33 of the BF-0.35BT ceramic was attributed to a weak relaxor behavior between coexisting macrodomains and polar nanoregions. The presented strategy provides guidelines for designing high-temperature BF-BT ceramics for different applications.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
PubMed
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
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2024
·
IF 3.9
Xianzhao Zhang,Qiyi Yin,Hengwen Cheng,Ruihua Zheng,Hui Zhang,Kunhong Hu,Fei Lin,Liping Fang,Shicheng Wang,Zhen Zhang
In this study, new lead-free piezoelectric ceramics (1 − x )(K 0.5 Na 0.5 )NbO 3 (KNN)– x (Bi 0.45 Y 0.05 )Na 0.5 ZrO 3 (BYNZ) were prepared using the conventional solid-state method, and the relation between the doping amount of (Bi 0.45 Y 0.05 )Na 0.5 ZrO 3 and its structural and electrical properties was investigated. Material characterization and structural analyses conducted using X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy revealed that KNN–BYNZ ceramics formed single perovskite structures at 0 ≤ x ≤ 0.05 and a polycrystalline phase boundary (PPB) for the coexisting orthorhombic and tetragonal phases at 0.03 ≤ x ≤ 0.05. The ceramics exhibited desirable electrical properties at x = 0.04 ( d 33 = 305 pC/N, k p = 45.8 %, ε r = 1316, tanδ = 2.4 %, T c = 332 °C, P r = 28.2 μC/cm 2 , and E c = 1.07 kV/mm). These findings reveal that the introduction of BYNZ enables the effective formation of a PPB in the KNN-based ceramics to improve their electrical properties, and they exhibit potential for replacing lead-based piezoelectric ceramics in the market.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）