INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Ying Chen,Rongfei Wei,Lanjiao Li,Xiangling Tian,Fangfang Hu,Hai Guo
High-performance near-infrared (NIR) light sources are highly sought after in advanced spectroscopy techniques, driving the development of NIR phosphor-converted light-emitting diodes (pc-LEDs). Escalating the luminescence intensity and thermal stability of NIR-emitting phosphors, which is a core component of NIR pc-LEDs, is of paramount importance. Herein, chemical unit cosubstitution and cosolvent addition tactics were implemented to simultaneously boost the NIR luminescence performance of the synthesized phosphors. The replacement of [Sc3+-Sc3+] for [Ca2+-Zr4+] in Ca4ZrGe3O12:Cr3+ likely reduces the antisite defects and offers a more rigid crystal structure. As a result, the emitting intensity is reinforced significantly, along with a remarkable improvement in thermal stability, acquiring 65% of the initial luminescence at 423 K compared with 42% for the primal sample. Moreover, the introduction of H3BO3 further enhances NIR luminescence while maintaining a favorable thermal resistance. The encapsulated NIR pc-LED carries an impressive output power of 71.8 mW at 300 mA and a conversion efficiency up to 15.6% at 10 mA. The practical presentations in food checking, imaging, and detection manifest that Ca3.5ScZr0.5Ge3O12:Cr3+,H3BO3 is a promising material for spectroscopy-based technologies.
研究领域:
材料科学
·
光学
·
无机化学
✓ 已验证
DOI
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2024
·Vol. 90
·期 1
·32-44
·
IF 2.5
Cao Shuqin,Li Yubiao,Wu Xiaoyong,Li Wanqing,Yang Xu
View large Download slide View large Download slide Close modal Developing a feasible and low-cost strategy for the recovery of calcium fluoride efficiently from fluoride-containing wastewater is very essential for the recycle of fluoride resources. Herein, a modified lime precipitation method was employed to recover CaF 2 from fluorinated wastewater using a special icy lime solution. Intriguingly, the highest F – removal was greater than 95% under the optimal condition, leaving a fluoride concentration from 200 to 8.64 mg/L, while the lime dosage was much lower than that of industry. Importantly, spherical-shaped CaF 2 particles with a 93.47% purity and size smaller than 600 nm were recovered, which has a high potential for the production of hydrofluoric acid. Besides, the precipitation was significantly affected by Ca/F molar ratio, stirring time, temperature, and solution pH. Furthermore, the thermodynamics and kinetics were investigated in detail to reveal the crystallization process. As a result, the defluorination reaction followed the pseudo-second order reaction kinetics model. Also, CO 2 in the air adversely influenced the CaF 2 purity. Based on this facile method, a high lime utilization efficiency was applied to defluorination, which contributed to protecting the environment and saving costs. This study, therefore, provides a feasible approach for the green recovery of fluorine resources and has significance for related research. A facile icy lime precipitation method was employed to remove F − . Highly pure spherical particles with CaF 2 of more than 93% were recovered. Thermodynamics implied that CO 2 had an inhibitory effect on the purity of CaF 2 . Change in F fitted well with the pseudo-second order reaction kinetics model. The co-precipitation of CaF 2 and CaCO 3 occurred.
研究领域:
环境工程
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化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Sujuan Wang,Qing Luo,Xiaohua Luo,Shengcan Ma,Changcai Chen,Fei Gao,Bodong Lv,Rui Zhong,Weijun Ren,Zhenchen Zhong
The effects of Si and Cu doping on crystal structures, magnetism , and the magnetocaloric effect of EuAl 4 have been investigated. EuAl 4 , EuAl 3.35 Si 0.65 , and EuAl 3.82 Cu 0.18 single crystals grown by the Al flux method are isotypic and crystallize in BaAl 4 -type structure with space group I 4 /mmm . Compared to the pristine compound EuAl 4 , the lattice parameter a keeps almost unchanged and c decreases obviously by Si doping, while a decreases and c increases upon Cu-substitution. These irregular changes in the lattice parameters may contribute to the electronegativity difference between Si and Cu. Cu and Si doping enhances the ferromagnetic interaction, and the direction of easy magnetization changes from the ab plane to the c axis upon the Cu-substitution. Multiple-step metamagnetic transitions are still observed in EuAl 3.35 Si 0.65 as applying the magnetic field along the c axis, while EuAl 3.82 Cu 0.18 shows ferromagnetic behavior along the ab plane and c axis. As a consequence, the low-field magnetocaloric effect is significantly enhanced. The maximum magnetic entropy change under a field change of 20 kOe increases from − 8.4 J/kg K for EuAl 4 to − 12.9 J/kg K for EuAl 3.35 Si 0.65 and − 15.9 J/kg K for EuAl 3.82 Cu 0.18 . The corresponding values of refrigerating capacity are 67, 140, and 147 J/kg, respectively. The remarkable magnetocaloric performances suggest that the Cu-doped EuAl 4 compound is an excellent candidate material for low-temperature magnetic refrigeration.
研究领域:
凝聚态物理
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材料科学
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磁学
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低温物理
·
功能材料
✓ 已验证
DOI
高影响因子
Progress in Natural Science-Materials International
·
2018
·Vol. 28
·期 4
·529-533
·
IF 2.572
Zhenmin Ding,Yufei Ma,Dandan Peng,Lu Zhang,Yumeng Zhao,Yuan Li,Shumin Han
In this work, LiBH 4 –20 wt% PP composite was prepared by ball-milling with as-synthesized hierarchical pyrolysis polyaniline (PP) and LiBH 4 , and the hydrogen sorption performance as well as catalytic mechanism of the composite was studied. It is found that the onset desorption temperature of the composite decreases to 75 °C, almost 235 °C lower than that of the milled LiBH 4 . Moreover, the composite could release 4.1 wt% H 2 and rehydrogenate a total of 4.4 wt% H 2 when the temperature raiseds up to 400 °C, showing an outstanding reversibility, which even 3.9 wt% H 2 can be kept after five cycles. Through scanning electron microscopy (SEM) observation and X-ray diffraction (XRD) analysis, we found that the PP surface forms some nanoholes after hydrogenation-dehydrogenation cycles, which leads to the confinement of some LiBH 4 in the PP nanoporous structure, therefore, the hydrogen sorption kinetics and reversibility are significantly enhanced. In addition, we also found the oxygenic groups of the PP can react with LiBH 4 forming LiBO 2 and Li 3 BO 3 , where the containing Li–B–O bonds loaded in the porous structure of the PP catalyze the hydrogenation reaction of LiBH 4 .
研究领域:
材料科学
·
能源化学
·
纳米材料
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固态储氢
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催化化学
✓ 已验证
DOI
高影响因子
THIN SOLID FILMS
·
2013
·
IF 1.604
Shufang Wang,Shanshan Chen,Guoying Yan,Fuqiang Liu,Shouyu Dai,Jianglong Wang,Wei Yu,Guangsheng Fu
c-axis oriented nanocrystalline Bi 2 Sr 2 Co 2 O y thin films with the average grain size of 25 nm have been achieved by chemical solution deposition combined with a rapid annealing process in oxygen. The resistivity and Seebeck coefficient of the nanostructured films are about 7.0 mΩ·cm and 171 μV/K at 873 K, resulting in a power factor 2–3 times larger than that of the best reported value in the coarse-grained Bi 2 Sr 2 Co 2 O y polycrystalline bulks. Since the thermal conductivity can be greatly reduced due to the increased phonon scattering at the grain boundaries of nanocrystalline films as well as at film surface and at film/substrate interface, great improvements in the ZT are expected in the nanocrystalline Bi 2 Sr 2 Co 2 O y thin films .
研究领域:
材料科学
·
凝聚态物理
·
无机非金属材料
·
能源材料
✓ 已验证
DOI
高影响因子
Nano Select
·
2021
·Vol. 2
·期 11
·2225-2236
·
IF 0
Ling Chen,Shishuo Liu,Xinfu Cao,Jianbing Gao,Yingbo Wang,Yang Qin,Yang Zhang,Jianwei Zhang,Guorui Jin,Moru Wang,Jie Liu,Weidong He
In order to investigate the thermal decomposition kinetics and mechanism of nitrocellulose (NC) based nitramine explosives nanocomposite energetic materials, this work prepares NC/RDX (cyclotrimethylenetrinitramine), NC/HMX (cyclotetramethylenetetranitramine), and NC/CL-20 (hexanitrohexaazaisowurtzitane) composites by a combined sol-gel and the freeze-drying technology. The structure is systematically investigated and the results reveal that the explosive particles are dispersed, filled, or embedded homogenously in the gel matrix of NC, thereby restricting the crystal growth of RDX, HMX, CL-20 particles to coarse and achieving submicron/nanometer. The thermal analysis of composites exhibits much lower peak temperature compared with raw explosive crystal, furthermore, the activation energy ( E a ) of composites is also lower than that of both NC and explosives. Hence, the unique structure of NC gel matrix embedded explosives inside demonstrated different mechanism of decomposition. Concretely, the rupture of the H-NCO = O bond in the cross-linked structure is detected firstly, subsequently, the macromolecular chains’ scission site of gel firstly occurs at -C-O-C- in the ring, and then the scission of -NO 2 (from NC or explosive crystals) bonds happened. Hence, this study may provide promising fabrication strategy and basic theory for the application of NC-based nanocomposite energetics in high-energy propellants and explosives.
研究领域:
材料科学
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化学工程
·
物理化学
✓ 已验证
DOI
ACS Applied Optical Materials
·
2024
·
IF 0
Lei Jin,Shuting Liu,Haoran Zhang,Wei Li,Jianle Zhuang,Chaofan Hu,Yingliang Liu,Mingtao Zheng,Xuejie Zhang,Bingfu Lei
The development of laser-driven lighting is progressing toward achieving high-power and high-brightness capabilities. However, all-inorganic color converters still face significant challenges arising from heat accumulation. Herein, we propose an effective approach to enhance the thermal conductivity of the light converter by closely sintering Y3Al5O12:Ce3+ (YAG:Ce3+) phosphor-glass films on a highly thermally conductive BN substrate (abbreviated as PBNC) for localized heat dissipation. This results in a significant increase in the luminescence saturation threshold when exposed to blue laser irradiation. The laser bearing capacity of PBNC is effectively optimized by adjusting the ratio of phosphor to glass and the thickness of the BN substrate. Under a laser irradiation level of 4.47 W/mm2 for 3 min, the maximum surface temperature of the PBNC is 92 °C, representing a significant reduction of 44 °C compared to that of the phosphor-glass film on the AlN substrate (136 °C). A laser-driven lighting device employing a PBNC with a thickness of 2.5 mm gives a luminous flux of 590.4 lm and luminous efficacy of 173.6 lm/W under a laser power density of 5.07 W/mm2. These findings confirm that the BN substrate enhances the thermal conductivity of phosphor-glass films, enabling them to become highly promising color converters for laser-driven lighting.
研究领域:
光学工程
·
材料科学
·
照明技术
✓ 已验证
DOI
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Jing Fan,Bin Cui,Shuangshuo Liu,Fenhong Song,Xiaopo Wang
Biodiesel has been considered as one of the feasible attempts to replace the fossil fuels. Alcohols always played a role as the additives to improve the certain properties of biodiesel. In this work, the liquid thermal conductivity of binary mixtures of methyl laurate usually the significant biodiesel component with three alcohols (1-propanol, 1-butanol and 1-pentanol) was measured with the temperature ranging within 287 K to 358 K at atmospheric pressure. The total standard uncertainty of the experimental results was estimated to be less than 2% (in the 0.68 confidence level) and the repeatability was better than ±0.5%. In addition, three useful correlations for estimating the thermal conductivity of mixtures have been fitted and optimized, and the maximum deviation of three correlations were less than 1.30%.
研究领域:
能源化学
·
燃料科学
·
热物理性质
·
可再生能源
·
生物燃料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2013
·Vol. 4
·期 2
·954-958
·
IF 2.562
Guihua Li,Xuzhong Cui,Cuiying Tan,Nan Lin
Uniform and polycrystalline tellurium nanoplates with a thickness of 100–300 nm can be rapidly synthesized by a simple solvothermal method in mixtures of water and ethanediamine at 180 °C with the assistance of glucose. By adjusting the concentration of glucose, tellurium microrods and nanoplates can be prepared. Based on the electron microscope observations, a possible mechanism involved the self-assembly process and dissolution–recrystallization mechanism is proposed for explaining the formation of polycrystalline tellurium nanoplates and their transformation into single crystalline nanorods. Furthermore, the Raman scattering measurement for the different morphologies is conducted, and the polycrystalline nanoplates present the stronger Raman scattering spectrum.
研究领域:
材料科学
·
纳米技术
·
无机化学
·
凝聚态物理
·
光谱学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yonghui Xu,Liang Zhang,Shuwen Yin,Xiudi Wu,Hongpeng You
Despite significant progress has been made in the luminescent materials for white light emitting diodes (WLEDs), it is still desirable to develop novel highly efficient phosphors with appropriate excitation and high visible emission for high color rendering WLEDs. In this study, we report a novel phosphor BaGa 2 Si 2 O 7 :Ce 3+ ,Tb 3+ (BGSO:Ce 3+ ,Tb 3+ ) with highly effective green luminescence. BGSO:Ce 3+ ,Tb 3+ phosphor represents a broad excitation band in the range of 300–400 nm and intense emission at approximately 542 nm with a high photoluminescence quantum efficiency of 76.4%. The structure, luminescence, and energy transfer from the Ce 3+ and Tb 3+ ions were investigated in detail. Moreover, the incorporation of Na + or K + ions into BGSO:Ce 3+ ,Tb 3+ for charge compensation can improve the emission intensity and thermal stability. Moreover, a near ultraviolet (n-UV) pumped prototype WLED device was fabricated and it exhibited bright warm-white light with CIE chromaticity coordinates of (0.3561, 0.3344), high color-rendering index (Ra=90.4), and low CCT (3330 K) upon 20 mA driving current. This work provides a new strategy to develop high-quality solid-state LED phosphors.
研究领域:
材料科学
·
光学工程
·
固体物理
·
发光材料
·
半导体器件
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 21
·30039-30042
·
IF 4.527
Leihao Feng,Qiwei Hu,Li Lei,Lei Qi,Leilei Zhang,Meifang Pu,Zili kou,Fang Peng,Duanwei He,Yohei Kojima,Hiroaki Ohfuji,Tetsuo Irifune
High-hardness TaN compacts with a diameter and height of 6 mm were synthesized through the phase transformation of CoSn-type into WC-type TaN under experimental conditions of high temperature and high pressure . The Vickers hardness of WC-type TaN compacts obtained at the pressure of 5 GPa and the temperature of 1873 K is found to be ~21.5 ± 1.5 GPa with a load of 3 Kg, which is comparable to that of the pure tungsten carbide compact (~20 GPa) and higher than those of ultrahigh temperature ceramics ZrB 2 and HfB 2 under the same load. The high hardness of WC-type TaN compacts presented in this work is attributed to the deviatoric strain and well-bonded nanograins . The synthesized WC-type TaN compacts also possess a high oxidation temperature (1072 K). These results suggest that the WC-type TaN with high hardness and high thermal stability holds great promise for industrial applications.
研究领域:
材料科学
·
无机非金属材料
·
超硬材料
·
高温材料
·
固态化学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2018
·
IF 2.687
Huan Zhou,Ying Yang,Mengmeng Yang,Wenjie Wang,Yaping Bi
Mesoporous hydroxyapatite is widely applied in biomedical and environmental fields due to its high surface area and adsorption capacity. In current work a one-step hydrothermal method to synthesize mesoporous HA was developed with the assistance of a cost-effective template vitamin C. It was observed the pore size and morphology of hydrothermally synthesized HA were correlated to applied solution composition. A combination of calcium hydroxide, orthophosphate, and vitamin C can finally result in mesoporous rod-like HA nanoparticles with surface area of 88 m 2 .g −1 and pore size of 15.7 nm on average. The mesoporous HA exhibited enhanced adsorption of model drug doxorubicin in comparison to conventionally synthesized HA as expected. Consequently, this work provides new pathway to prepare mesoporous HA with advantages of economy and convenience.
研究领域:
生物材料学
·
纳米医学
·
药剂学
·
环境科学
·
生物无机化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）