ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zhihang Zhang,Wenjing Zhai,Guangyuan Li,Wenhao Zheng,Xinyu Li,Lin Huang,Liufang Chen,Lin Lin,Guoliang Yuan,Zhibo Yan,Jun-Ming Liu
Tin halide perovskites are rising as promising candidates for next-generation optoelectronic materials due to their good optoelectronic properties and relatively low toxicity. However, the high defect density and the easy oxidation of Sn2+ have limited their optoelectronic performance. Herein, we report the treatment of the FASnI3 (formamidinium tin, FA) perovskite film by a bifunctional cesium fluoride (CsF) additive, which improves the film quality and significantly enhances the photoelectric performance. The responsivity of the perovskite-based photodetector (PD) with an optimal CsF concentration of 15% is over 60 times larger than that of the PD without CsF. It indicates that both the Cs substitution and the fluoride anion additive from CsF inhibit the oxidation of Sn2+, optimize the crystal growth, and passivate the defects, demonstrating the dual roles of the CsF additive in improving the photoelectric performance. This work offers valuable insights into the additive selection for developing high-quality tin-based perovskite films and devices.
研究领域:
材料科学
·
光电子学
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纳米技术
·
化学工程
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DOI
高影响因子
Materials Today Chemistry
·
2024
·
IF 6.7
Tao Yang,Lingxiang Chu,Yi Qin,Qiang Zhou,Jing Wan,Huaijun Tang,Yanqing Ye,Zhengliang Wang
The quest for efficient and heat-resistant near-infrared (NIR) phosphors to create advanced smart NIR lighting sources continues to pose a significant challenge. This study introduces a new fluoride phosphor, Cr 3+ -doped Cs 2 NaScF 6 , wherein the Cs 2 NaScF 6 host provides a weak crystal field suitable for Cr 3+ doping. This arrangement allows the production of a broad NIR emission peaking at 797 nm, coupled with a notable internal quantum efficiency of 90.8 % when excited by 446 nm blue light. Meanwhile, due to the relatively mild electron-phonon coupling effect and a high activation energy within this phosphor, the overall NIR emission intensity at 150 °C sustains 81.8 % of its level at room temperature. This highlights exceptional thermal stability in photoluminescence performance. Combining the Cs 2 NaScF 6 :Cr 3+ phosphor with a commercially available blue InGaN chip to construct a NIR light-emitting diode (LED) device, which exhibits efficient and stable NIR emission, making it suitable for non-destructive testing applications. These findings affirm that the Cs 2 NaScF 6 :Cr 3+ phosphor can function as a promising candidate to fabricate high-performance device for NIR spectroscopy application.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
Energy Storage Materials
·
2024
·
IF 18.9
Wenxia Sima,Yuxiang Mai,Potao Sun,Ming Yang,Tao Yuan,Binghao Chen,Yuhang Yang
Polyimide, endowed with high thermal resistance due to its aromatic structure, is considered a potential candidate for high-temperature polymer dielectrics. However, the strong electron delocalization in the aromatic structure causes significant leakage current during high-temperature electron transport, impairing energy storage performance. This contradictory relationship presents a bottleneck in enhancing the high-temperature energy storage performance of PI. In this work, inspired by fish migration influenced by vortices, we propose inducing electron displacement through fluorine-modified aromatic structures, constructing an internal electric field in PI to affect electron transport. This approach cleverly resolves the conflict between thermal resistance and current loss caused by the aromatic main chain in PI, achieving a synergistic enhancement of thermal resistance and high-temperature energy storage performance. Experimental results show significant improvements in both the high heat-resistant quality and high-temperature energy storage performance of PI. The glass transition temperature increased from 257.32 °C to 264.07 °C, and the leakage current density decreased from 7.1 × 10 –7 A/cm 2 to 2.8 × 10 –8 A/cm². Simultaneously, with a charge-discharge efficiency of approximately 90 %, the discharge energy density increased from 0.36 J/cm 3 to 5.22 J/cm 3 , an improvement of 1345.98 %. This strategy validates the potential of aromatic structures as the main chain for high-temperature energy storage polymers.
研究领域:
材料科学
·
能源存储
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2024
·
IF 4.1
Hao Zheng,Zejun Zheng,Dirong Gong,Chun Tian,You Wen,Zhen Wang,Jingling Yan
The rapid development of high-speed communication networks has imposed more stringent requirements on the comprehensive performance of dielectric materials. In this work, a series of fluorinated poly(aryl ether)s (FPAEs) were prepared from 4,4′-dihydroxy-2,2′-bis(trifluoromethyl)biphenyl (TFBP) and different difluoride monomers through nucleophilic substitution reactions. The FPAE films had good thermal stability, with 5% weight loss temperature (Td5) values of 514–555 °C in nitrogen and glass transition temperature (Tg) values of 178–226 °C. Furthermore, these polymer films showed excellent hydrophobicity, with water contact angles ranging from 92.4° to 98.7°, and water absorption of 0.28–0.87%. Consequently, the FPAE films showed low dielectric constants of 2.07–2.80 and low dielectric loss of 0.002–0.006 at 11 GHz and 30 °C. These outstanding properties were attributed to their high fluorine contents and twisted biphenyl structures in the polymer chains.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Lisha Liang,Yuxiang Zhao,Wuxin Zhang,Haokai Yan,Mengwei Chen,Yuan Chen,Jin Zhou,Tao Zhang
The sp 2 -carbon-conjugated porous polymers (sp 2 c-CPPs) that possess high porosity, chemical stability, and carrier mobility are potential for uranium extraction from seawater, which is tremendous meaningful for the rapidly growing demands of the nuclear industry due to the abundant uranium resources (4.5 billion tons) in ocean. Here, we report the synthesis of three sp 2 c-CPP films (DMPN-TFPT, BN-TFPT and TMTN-TFPT) directly on Cu substrate that can work as electrodes for electrochemical uranium extraction. Furthermore, we designed a photovoltaic-electrocatalysis (PV-EC) system to enhance the uranium extraction capacity, meanwhile, modified oxime groups on sp 2 c-CPPs film to enhance uranium ion selectivity. The DMPN-TFPT electrode shows ultra-high uranium extraction performance (1022.02 mg m −2 ) in 8 ppm uranyl-spiked simulated seawater, which is higher than that of BN-TFPT film (426.27 mg m −2 ) and TMTN-TFPT film (607.30 mg m −2 ) because of the higher in-plane electron delocalization. Additionally, in ultra-low concentration of simulated seawater (3.3 ppb), the DMPN-TFPT film also exhibited a high capacity up to 81.74 mg m −2 within 30 days. This work shows the great potential of sp 2 c-CPP films on solar-driven electrochemical uranium extraction.
研究领域:
材料科学
·
环境工程
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核工程
·
电化学
·
太阳能
✓ 已验证
产品关联
DOI
高影响因子
Optics
·
2025
·Vol. 7
·期 1
·1
·
IF 1.6
Chenxing Liao,Huihuang Cai,Jiabao Wu,Wei Xie,Liaolin Zhang
Mn4+-activated fluoride phosphors possess outstanding luminescent properties, making them highly suitable for applications in lighting and display technologies. However, the synthesis of such phosphors generally requires the use of large amounts of highly toxic aqueous HF, leading to serious environmental pollution. To eliminate the use of hazardous HF solution, a low-temperature molten salt method employing NH4HF2was developed to synthesize the narrow-band red emitter Cs2GeF6: Mn4+phosphor. Following the reaction, the product was washed with a dilute H2O2solution to remove residual NH4HF2and other impurities. The phase purity and morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively, and the luminescence properties were examined via photoluminescence (PL) spectroscopy. The obtained phosphors exhibit bright red emission characteristics of Mn4+under blue-violet excitation. Among them, Cs2GeF6: 0.08 Mn4+shows the highest emission intensity, with an internal quantum efficiency (IQE) of 78%. A white light-emitting diode (WLED) fabricated by combining this phosphor with a blue chip and commercial Y3Al5O12: Ce3+(YAG) phosphor achieved a high luminous efficacy (LE) of ~146 lm/W, a correlated color temperature (CCT) of ~4396 K, and a color rendering index (Ra) of ~83, alongside excellent operational color stability.
研究领域:
材料科学
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光电子学
·
固态化学
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发光材料
·
LED技术
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产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Jun Zheng,Linglin Wang,Lei Feng,Yuhan Gao,Feiyao Ren,Siyu Liu,Ting Zhou,Xiaochun Wu,Xin Lai,Daojiang Gao
Recently, Mn 4+ -activated fluoride red phosphors have received intensive attention due to their excellent luminescence properties. However, poor moisture resistance hinders their commercial application. Herein, (K 1- x Cs x ) 2 NbF 7 :Mn 4+ phosphors were designed and synthesized. All the obtained samples are rod-like microcrystals with monoclinic phase structure, Cs + -doping concentration has little influence on the microstructure while significantly impacts their luminescence properties. Specially, the composition optimized (K 1- x Cs x ) 2 NbF 7 :Mn 4+ ( x = 0.3) phosphor has the color purity of 94.20 %, the quantum yield of 53.90 % and the decay lifetime of 3.59 ms. More importantly, the optimized phosphor can maintain 83.20 % of the initial emission intensity after being immersed in distilled water for 1440 min, showing the excellent moisture resistance. A warm WLED with high CRI of 85 and low CCT of 4362 K is achieved by coating the obtained optimized red phosphor in chip. Our work demonstrates that the (K 1- x Cs x ) 2 NbF 7 :Mn 4+ red phosphors possess a great potential application in warm WLEDs.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
GIANT
·
2024
·
IF 5.4
Hong Li,Weiyi Jin,Weiyu Zhang,Jie Li,Jiaqi Ji,Yi Tang,Tianqi Yang,Shujiang Zhang,Haixia Yang,Chenliang Gong
Low-dielectric, transparent, and high-heat-resistant polyimide (PI) films are vital for flexible electronics and high-frequency communication devices. However, balancing these properties within intrinsic polyimides remains a significant challenge. In this work, a nonplanar diamine monomer, 2,7-bis(3,5-bis(trifluoromethyl)phenyl)-9,9-bis(4-nitrophenyl)-9H-fluorene (BTFDA), containing a Cardo structure and four trifluoromethyl groups, was synthesized and copolymerized with commercial monomers to produce a series of polyimides (CPI-X). These CPI-X exhibit exceptional heat resistance, with glass transition temperatures ( T g ) exceeding 350 °C, decomposition temperatures ( T d5 % ) above 530 °C, and low thermal expansion coefficients (CTE < 20.8 ppm/K). Additionally, they have excellent optical properties with over 92 % transparency at 450 nm and low birefringence (Δ n = 0.00042). They also demonstrate good hydrophobicity with low water absorption ( M a % = 0.04 %) and high-water contact angles ( C a = 97.6°). Most importantly, the CPI-X films show excellent dielectric properties ( D k = 2.25, D f = 0.00365 at 1 MHz, D k = 2.13, D f = 0.0065 at 10 GHz). Such intrinsic PI films with low D k values may be ideal candidates for next-generation interlayer media.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·
IF 13
Xiaowen Wang,Hong Zhang,Ping-Ping He,Xiaoxue Du,Yuxin Shen,Wensheng Cai,Weiwei Guo
With sequence-programmable biological functions and excellent biocompatibility, synthetic functional DNA holds great promise for various biological applications. However, it remains a challenge to simultaneously retain their biological functions while protecting these fragile oligonucleotides from the degradation by nucleases abundant in biological circumstances. Herein, a smart delivery system for functional DNA payloads is developed based on proton-mediated dynamic nestling of cytosine-rich DNA moieties within the precisely size-matched nanochannels of highly crystalline metal–organic frameworks (MOFs): At neutral pH, cytosine-rich DNA strands exhibit a flexible single-stranded state and can be accommodated by MOFs nanochannels with a size of ca. 2.0 nm; while at acidic conditions, the protonation of cytosine-rich strands weakens their interaction with the nanochannels, and the tendency to form four-stranded structures drives these DNA strands out of the nanochannels. Results confirm the successful protection of DNA payloads from enzymatic hydrolysis by the MOFs nanochannels, and the delicate coupling of the endocytosis processes and the proton-responsive Cytosine-rich DNA/MOFs systems realized the efficient intracellular delivery of DNA payloads. Furthermore, with a complementary sequence to the telomere overhangs, direct imaging of telomeres and the nucleus is successfully achieved with the proton-mediated DNA/MOFs system.
研究领域:
生物技术
·
纳米技术
·
分子生物学
·
药物递送系统
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Hong Li,Xiaoqian Lan,Feng Bao,Shuanger Li,Haoran Zhu,Zijuan Zhu,Yadong Li,Mingliang Wang,Caizhen Zhu,Jian Xu
Polyimide (PI), as an ideal interlayer dielectric material, is widely used in traditional communication fields. However, with the rapid development of 5G communication, conventional polyimide exhibits disadvantages such as signal delay and missing and is in urgent need of modification. Based on the β-relaxation theory, we designed and prepared three types of triphenylenediamine-containing monomers with different side group sizes (A-AmM, A-AmP, and A-AmBP) and polymerized them with benzene tetracarboxylic dianhydride (PMDA) to obtain three types of polyimides (MPI, PPI, BPPI), to investigate the effect of the relaxation behavior on the dielectric constant (D k ) of the polyimide. It was also polymerized with 4,4′-(hexafluoroisopropyl)diphthalic anhydride (6FDA) to three fluorinated Polyimides (MFPI, PFPI, BFPPI) to investigate the effect of polar groups on D k and the dielectric loss (D f ). In addition, we also calculate the free volume of polyimide molecules under different side groups by materials studio simulation to further verify the effect of side groups on the D k . The results show that, firstly, with the increase of side group volume, polyimide still maintains excellent thermal stability, and its dielectric constant gradually decreases and mechanical strength gradually increases. Secondly, the dielectric constant of FPIs is significantly lower than that of the PIs due to the low polar group, and the thermal and mechanical properties are almost unchanged. In addition, benefiting from the combined effects of β-relaxation and trifluoromethyl groups, BPFPI exhibits a low D k (2.64@10 GHz) and D f (0.0092@10 GHz), excellent thermal properties (glass transition temperature (T g ) = 282.3 °C, 5 % decomposition temperature (T d5% ) = 537 °C) and excellent mechanical properties (tensile modulus = 1.71 GPa, tensile strength = 134.7 MPa).
研究领域:
材料科学
·
电子通信
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2024
·
IF 7.2
Huan Pei,Luyong Zhang,Huanhuan Cheng,Shibin Wang,Zhihua Yang,Fangfang Zhang,Shilie Pan
Four hydroxyfluorooxoborates, α-K2[B3O3F4(OH)] (I), β-K2[B3O3F4(OH)] (II), Cs(NH4)3[B3O3F4(OH)]2 (III), and RbCs5[B3O3F4(OH)]3 (IV), with identical fundamental building block (FBB) [B3O3F4(OH)]2–, were obtained successfully and characterized comprehensively. A phase transition between I and II was detected, which led to a space group evolution from centrosymmetric to noncentrosymmetric. The F– and OH– substitution effect was studied based on II and its hydroxyborate derivative K2[B3O3(OH)5], which reveals the corresponding changes in the band gap and the nonlinear optical properties. In addition, the cationic-size effect on the arrangement of the [B3O3F4(OH)]2– FBBs and the birefringent properties were discussed for the title compounds. This study contributes to the advancement of structural chemistry and sheds some light on the structure–property relationship studies of hydroxyfluorooxoborates.
研究领域:
材料化学
·
晶体学
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产品关联
DOI
高影响因子
MACROMOLECULES
·
2024
·
IF 5.1
Kai Geng,Tengyao Xue,Xiaodan Li,Haoqi Sang,Shichao Feng,Chenyi Wang,Hanli Wang,Yongbing Zhuang
In this study, a novel diamine monomer (BTPA) containing a benzocyclobutene (BCB) cross-linking site was synthesized, and two polyimides (PIs), PI-BCB-1 and PI-BCB-2, were synthesized using BTPA with dianhydrides, 4,4′-(hexafluoroisopropyl) diphenyl anhydride (6FDA) and 4,4′-(4,4-isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA), respectively. The BCB-based PIs were soluble in common organic solvents and exhibited a desirable toughness. The cross-linking behavior of the BCB-based PIs was investigated using nonisothermal differential scanning calorimetry, and a mathematical model for the curing kinetics was established. Further, the effects of BCB cross-linking on the interchain packing, thermal performance, and gas transport properties of the PIs were thoroughly examined. The cross-linked PIs exhibited excellent heat resistance with glass-transition temperatures exceeding 400 °C. In addition, the CO2 and CH4 permeabilities for the cross-linked PI membranes increased 16- and 27-fold, respectively, compared with their counterparts before cross-linking. Remarkably, the CO2 permeability for PI-BCB-1 increased from 33 to 1559 Barrer after cross-linking, while maintaining a nearly unchanged CO2/CH4 selectivity of 35 (39 for its uncross-linked counterpart), surpassing the 2008 Robeson upper limit. In addition, the cross-linked PI membranes showed desirable aging resistance and excellent plasticization resistance. This study offers insights for designing PIs containing BCB side group-cross-linked units to enhance membrane-based gas separation performance.
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产品关联
DOI
高影响因子
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