Journal of Physical Chemistry C
·
2017
·
IF 4.536
Zhan Zhang,Lixia Ren,Hong Yan,Shujin Guo,Shuanhu Wang,Min Wang,Kexin Jin
Single crystals of heterovalent Bi-doped CH3NH3PbCl3 perovskite have been successfully grown through the inverse temperature crystallization method. Bandgap narrowing of 300 meV (a 55 nm red-shifting absorption edge) is obtained for the nominal 20% Bi-doped crystal with the host structure and the energy at the top of the valence band invariable. It is observed that the contact between the Au electrodes and single crystals transforms from Ohmic to Schottky, and the conductivity increases with increasing Bi doping level. By contrast, the Bi-doped CH3NH3PbCl3 thin films are also prepared, and the similar bandgap narrowing is found, although the narrowing degree is less than that in single crystals. This work has a comprehensive understanding of Bi-doped single crystals and thin films, providing further optoelectronic applications for these promising solution-processed hybrid perovskite semiconductor materials.
研究领域:
材料科学
·
光学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Wang-Wei Liao,Lei Yang,Jie Chen,Da-Li Zhou,Xian-lin Qu,Kun Zheng,Guang Han,Jia-Bei Zhou,Min Hong,Zhi-Gang Chen
Copper selenide (Cu 2 Se) has been extensively studied as an eco-friendly thermoelectric candidate owing to the outstanding thermoelectric performance of its high-temperature β-phase. In this study, we propose that α-Cu 2 Se is also a promising thermoelectric material at near-room-temperature. We synthesize nanostructured Cu 2-x Se via a facile solvothermal method, and densify the samples using Spark Plasma Sintering to maintain the small grain sizes. Although the as-prepared α-Cu 2 Se has intrinsically low lattice thermal conductivity , its high Cu deficiency leads to a high carrier concentration, therefore, a low thermoelectric performance. As an electron donor, bismuth can effectively compress the Cu vacancies of the as-prepared α-Cu 2 Se and in turn reduce its carrier concentration from 4.1 × 10 20 to 2.0 × 10 20 cm −3 at room temperature, achieving a significantly enhanced power factor and a reduced carrier thermal conductivity. Consequently, a zT of 0.43 at 373 K is obtained in Cu 1.982 Bi 0.006 Se, showing great potential in developing high-performance near-room-temperature α-Cu 2 Se-based thermoelectric materials.
研究领域:
材料科学
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能源技术
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DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
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2017
·Vol. 121
·期 12
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IF 2.068
Wu Lei,Dai LiDong,Li HePing,Hu Haiying,Zhuang YuKai,Liu KaiXiang
We present a pressure-induced amorphization for pure and 0.5 mol. % Bi 3+ -doped Zn 2 GeO 4 samples, measured by high pressure Raman spectroscopy and high resolution transmission electron microscopy. Pressure-induced conductivity switching phenomena were discovered for both samples at around ∼7.01 GPa and ∼11.11 GPa, respectively, which closely correlated with the crystalline-to-amorphous transformation. The detailed conduction mechanism and the defect reaction process at high pressure indicate that the application of pressure could efficiently manipulate the microstructure and electrical performance of rare-earth doped polycrystalline materials, and therefore holds great promise for numerous applications in the future.
研究领域:
材料科学
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物理学
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DOI
高影响因子
ACS Nano
·
2023
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IF 17.1
Lihua Wu,Yue Luo,Chaofeng Wang,Shuilin Wu,Yufeng Zheng,Zhaoyang Li,Zhenduo Cui,Yanqin Liang,Shengli Zhu,Jie Shen,Xiangmei Liu
In this work, a biomimetic nanozyme catalyst with rapid and efficient self-bacteria-killing and wound-healing performances was synthesized. Through an in situ reduction reaction, a PCN-222 metal organic framework (MOF) was doped with bismuth nanoparticles (Bi NPs) to form Bi-PCN-222, an interfacial Schottky heterojunction biomimetic nanozyme catalyst, which can kill 99.9% of Staphylococcus aureus (S. aureus). The underlying mechanism was that Bi NP doping can endow Bi-PCN-222 MOF with self-driven charge transfer through the Schottky interface and the capability of oxidase-like and peroxidase-like activity, because a large number of free electrons can be captured by surrounding oxygen species to produce radical oxygen species (ROS). Furthermore, once bacteria contact Bi-PCN-222 in a physiological environment, its appropriate redox potential can trigger electron transfer through the electron transport pathway in bacterial membranes and then the interior of the bacteria, which disturbs the bacterial respiration process and subsequent metabolism. Additionally, Bi-PCN-222 can also accelerate tissue regeneration by upregulating fibroblast proliferation and angiogenesis genes (bFGF, VEGF, and HIF-1α), thereby promoting wound healing. This biomimetic enzyme-catalyzed strategy will bring enlightenment to the design of self-bacterial agents for efficient disinfection and tissue reconstruction simultaneously.
研究领域:
生物材料学
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医学
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催化科学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL TECHNOLOGY
·
2023
·
IF 2.8
Qian Yang,Wensong Lin,Zhichang Duan,Sen Xu,Junnan Chen,Xin Mai
In this work, g-C3N4/ZIF-8 heterojunction photocatalysts were synthesised by the process by which the metal-organic framework ZIF-8 nanoparticles were grown onto the g-C3N4 layer in situ. Bismuth element was doped into the as-prepared g-C3N4/ZIF-8 material and a new type of Bi@g-C3N4/ZIF-8 composite photocatalysts was manufactured, in which the doping element acts in adjusting the bandgap in the photocatalysts. The prepared photocatalysts were characterised by XRD, FESEM, TEM, FTIR, XPS, UV–VIS DRS, photoluminescence and photo-electrochemical experiments. The results show that the ZIF-8 nanoparticles grown in situ were well-formed onto the g-C3N4 layer, and bismuth was evenly doped into the gaps of the g-C3N4/ZIF-8 framework. The degradation rate of methylene blue by CNZ-1.5(Bi)-12, which was a photocatalyst composed of 12% Bi-doped with g-C3N4/ZIF-8 material (the mass ratio of g-C3N4: ZIF-8 = 1:1.5), reached 86.6% under visible light irradiation within 60 min. The free radical scavenging experiment and electron spin resonance spectroscopy showed that ∙OH was the main active substance. Bismuth doping into the photocatalytic system promotes the excitation of electrons from the valence band to the conduction band and provides a good channel for the transmission of photogenerated carriers as well. It is achieved that intensive visible light absorption, the enhanced separation efficiency of photogenerated carriers, and excellent thermal stability and high recyclability in the novel composite photocatalyst, owing to the synergistic effect of the introduced bismuth with the heterostructure of g-C3N4/ZIF-8. Therefore, the synthesised Bi@g-C3N4/ZIF-8 heterojunction photocatalysts may be used as a good photocatalyst for purifying and degrading organic matter in sewage.
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
PubMed
高影响因子
MATERIALS LETTERS
·
2023
·
IF 3
Jianfeng Tan,Weijia Ma,Gaoxiang Meng,Congkui Tian,Yin Wang,Yan Wang,Zhuo Liu
Room temperature (RT) gas sensors have been widely studied because of their low power consumption and easy integration. The low response value and long response/recovery time of gas-sensitive materials have hindered the development of RT gas sensors. In this paper, Bi-doped SnS 2 nanoflowers with high surface area were tailored by a novel hydrothermal method. A fast response/recovery speed of 52/100 s and high response (5.58) were obtained from 3 % Bi doped SnS 2 nanoflower for 1 ppm NO 2 . This work provides a strategy to fabricate RT gas sensors based on layered metal sulfide.
研究领域:
材料科学
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环境监测
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DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
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2024
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IF 2.5
Liang Yan,Yujing Zhang,Yilin Zhang,Rui Liu,Chuyang Liu,Fan Wu,Xuefei Miao,Er Liu,Xiaoling Peng,Jing Li,Shan Tao,Feng Xu
LaFeO 3 perovskite has possessed great potential in the field of microwave absorption considering its outstanding dielectric and magnetic properties. In this work, Bi-doped LaFeO 3 powders (BLFO) were prepared by a simple solid state reaction method. The results have demonstrated that the crystalline of LaFeO 3 and the lattice oxygen are increased with the additionally introduced Bi. As a result, the samples could exhibit the strongest microwave absorption with the minimum reflection loss (RL min ) of −39.48 dB and the effective absorption band (EAB) of 3.63 GHz (10.28–13.91 GHz) at a filling ratio of 60 wt%. The excellent microwave absorption properties are ascribed to the enhanced conductive loss, polarization relaxation and the co-existed magnetic loss. Moreover, the optimum sample exhibits the radar cross-section values below −10 dBm 2 across a wide angular range of −90° to 90° with a thickness of 2.5 mm. Therefore, this work opens up a feasible and effective way for modulating the electromagnetic properties of perovskite materials as potential microwave absorbents.
研究领域:
材料科学
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电磁学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
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IF 13.273
Xiaopei Zhu,Peng Shi,Ruirui Kang,Siyi Li,Zepeng Wang,Wenjing Qiao,Xiaoxiao Zhang,Liqiang He,Qida Liu,Xiaojie Lou
The application of dielectric capacitors with high energy density is very important to solve the increasingly serious energy crisis. However, the further improvement of energy density is seriously confining by their poor breakdown fields. In this work, outstanding energy storage performance is achieved in Sr 0.7 Bi x TiO 3 (x = 0.1, 0.2, 0.3 and 0.4) ceramics via A-site defect and grain size tuning. It was found that the moderate Bi 3+ content is helpful to reduce sintering temperature and refine grain size, which lead to higher activation energy and breakdown field. Besides, moderate Bi 3+ doping in A-site enhances polarity owing to the hybridizations between 6p orbital of Bi and 2p orbital of O. Thus, a high recoverable energy density of 4.77 J/cm 3 with prominent efficiency of 85.7% at 570 kV/cm is realized in Sr 0.7 Bi 0.2 TiO 3 ceramic. Moreover, the Sr 0.7 Bi 0.2 TiO 3 ceramic also displays superior thermal stability from 20 °C to 160 °C and excellent fatigue endurance over 10 5 cycles. Our results in this work offer a better understanding and design methodology for developing novel high-performance dielectric capacitors.
研究领域:
材料科学
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能源技术
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2018
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IF 6.759
Kai Yu,Da Lei,Yajun Feng,Haochen Yu,Yue Chang,Yanbing Wang,Yaqi Liu,Gui-Chang Wang,Lan-Lan Lou,Shuangxi Liu,Wuzong Zhou
Investigation of Bi-doping effects on the catalytic performance of Pt/3DOM-Ce 1−x Bi x O 2−δ in the aerobic oxidation of 5-hydroxymethyl-2-furfural allows us to reveal the promoted catalytically active sites: the asymmetrical oxygen vacancies coordinated with one Bi and up to three Ce cations, such as Bi-□(-Ce) 3 , where □ represents an oxygen vacancy, which can easily gain oxygen atoms in favor of the CeO 2 structure, and, when filled with oxygen, easily release oxygen anions in favor of six-coordination for Bi 3+ . The loss of electrons in the reduction of oxygen atoms at these sites would be replenished by electron transfer from Pt nanoparticles , eventually promoting the oxidation potential of the Pt nanoparticles. The present work points out that the promoted catalytic properties in Bi-doped CeO 2 are mainly due to the asymmetric structures of the oxygen vacancies, rather than simply to the number of oxygen vacancies. The newly proposed model of asymmetrical active sites and electron transfer mechanism may shed light on the physicochemical properties of other solid solution substrate-supported metal nanoparticle catalysts.
研究领域:
材料科学
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催化化学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2023
·Vol. 34
·期 6
·1-8
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IF 2.8
Xue Lisha,Wang Yuan,Zhu Shuangmei,Mao Qianhui,Jia Xiaopeng,Zhang Yuewen
We have synthesized the quaternary copper selenide Bi x Cu 2−3 x Se 0.95 Te 0.05 compounds by high-pressure followed with ball milling method and investigated their thermoelectric properties. The crystal structure and element doping are characterized and verified by the X-ray diffraction, high-resolution transmission electron microscope and X-ray photoelectron spectroscopy. Compared with other samples, the samples with x = 0.001 and 0.002 have larger layered grain size and smaller grain boundary. This may lead to the reduction of resistivity in a wide temperature range, thus realizing the optimization of electronic characteristics. The dislocation-induced lattice strain fluctuations may cause the abrupt thermal conductivity, which is contrary to the previous results. Eventually, a peak value of zT = 1.03 at 873 K is obtained for Bi 0.001 Cu 1.997 Se 0.95 Te 0.05 and Bi 0.002 Cu 1.994 Se 0.95 Te 0.05 .
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
Materials Today Chemistry
·
2022
·
IF 7.613
S. Wu,Y. Fu,Q. Liu,P. Xiong,D. Wang,G. Zhang,S. Yuan,Y. Chen
Developing highly efficient cyan-emitting fluorescent materials is essential to bridge the cyan gap in phosphor-converted white light-emitting diodes for full-spectrum white illumination. Here, a Bi-doped cyan phosphor has been reported to solve this gap. The phase purity, photoluminescence emission/excitation spectra, concentration quenching, lifetime decay curves, and temperature-dependent photoluminescence emission spectra were systematically investigated. SrLaGaO 4 :Bi 3+ exhibits a broad excitation band (250–400 nm), which matches with the emission of a commercial near-ultraviolet light-emitting diode chip. The cyan light peaked at 475 nm is observed, which is attributed to the 3 P 1 → 1 S 0 transition of Bi 3+ . The thermal quenching experiment was performed, and the activation energy was calculated as 0.36 eV. Finally, full-spectrum white light-emitting diode devices were fabricated using SrLaGaO 4 :Bi 3+ phosphors, commercial blue BaMgAl 10 O 17 :Eu 2+ phosphor, green (Ba, Sr) 2 SiO 4 :Eu 2+ phosphor, and red CaAlSiN 3 :Eu 2+ phosphor, which displayed an International Commission on an illumination coordinate of (0.3732, 0.3850), a correlated color temperature of 4290 K, and a color rendering index of 93.2 at a drive current of 20 mA. This result indicates that SrLaGaO 4 :Bi 3+ plays an essential role in bridging the cyan gap, providing new inspiration for applying cyan-emitting phosphors in full-spectrum white lighting.
研究领域:
材料科学
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光学工程
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固态照明
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发光材料
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无机化学
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
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2024
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IF 4.3
Panpan Xu,Congli Guo,Wentao Hao,Li Sun,Ensi Cao
The internal barrier layer capacitance effect substantially contributes to the colossal permittivity in In and Nb co-doped TiO 2 (INTO) ceramics. Therefore, enhancing grain boundary density and ceramic compactness can efficaciously reduce their low-frequency dielectric loss . In this investigation, Bi 2 O 3 addition was utilized to aid sintering and refine grains for INTO ceramics. The results reveal that Bi-doped INTO ceramics, in contrast to their undoped counterparts, exhibit a more refined and compact grain structure with a significant increase in the quantity of grain boundaries. Moreover, a noticeable reduction in low-frequency dielectric loss from above 0.1 to below 0.05 and enhanced frequency stability of permittivity from below 10 Hz to approximately 10 kHz were observed, along with a decrease in the sintering temperature to 1300 °C. In comparison to undoped INTO ceramics, Bi doping also enhances the withstand voltage capability by a factor of 1.5–4 for Bi-doped INTO ceramics. However, as the sintering temperature of Bi-doped INTO ceramics increases and the grain size enlarges, their breakdown voltage gradually decreases, but the non-linear coefficient of current-voltage characteristics progressively increases. Analysis of complex impedance spectra confirms that the increased grain boundary density and resistance in Bi-doped INTO ceramics is the primary factor for the enhanced dielectric properties and withstand voltage capability.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
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