Catalysts
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2020
·Vol. 10
·期 4
·377
·
IF 3.52
Wei Yu,Wenfeng Han,Yongnan Liu,Jiaqin Lu,Hong Yang,Bing Liu,Haodong Tang,Aimin Chen,Ying Li
BaClxFyas well as BaF2and BaClF catalysts were prepared by solid-state reaction at room temperature with Ba(OH)2as the precursor and NH4F/NH4Cl as the F and Cl sources. The catalysts were applied for the dehydrochlorination of 1-chloro-1,1-difluoroethane to vinylidene fluoride at 350 °C. The industrial manufacture of vinylidene fluoride (VDF) is carried out at 600–700 °C, whereas the BaClxFycatalysts provided a promising pathway to produce VDF at much lower temperatures. Unfortunately, the selectivity of VDF over BaF2decreased from 94% to 84% along with the deactivation of the BaF2catalyst monotonically. In the presence of small amounts of Cl in BaF2, stabilized selectivity was achieved. Over BaCl0.05F0.95, BaCl0.1F0.9and BaCl0.25F0.75, no decrease in VDF selectivity was observed. Clearly, the presence of small amounts Cl during solid-state preparation inhibited the growth of BaF2crystalline significantly. Far smaller particles were achieved. The particle size, or more precisely, the crystal size of the barium catalyst played a major role in the catalytic performance. In addition to the crystal growth, the presence of small amounts of Cl during catalyst preparation changed the chemical state of Ba, and therefore the adsorption and activation of the C–Cl bond for HCFC-142b were altered.Keywords:barium chlorofluoride;catalytic pyrolysis;barium fluoride;dehydrochlorination;1-chloro-1,1-difluoroethane;vinylidene fluoride
研究领域:
化学工程
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材料科学
·
催化
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高影响因子
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
·
2020
·
IF 1.265
Junjie Li,Jinghong Song,Weiwei Li,Bingchu Mei,Zuodong Liu,Yongqiang Zhang
In this study, high concentration (5 mol%) of cerium doped barium fluoride transparent ceramic was fabricated by hot pressing method t a temperature of 1200 °C under 30 MPa. XRD (X-ray Diffraction), SEM (Scanning Electron Microscope), PLE (Photoluminescence Emission) measurements was used to investigate the phase composition, microstructure as well as photoluminescence properties of Ce 3 + : BaF 2 . XEL (X-ray Excited Luminescence) and pulse height spectrum were used to investigate the scintillation properties of this ceramic. The phase composition and microstructure analyses showed that the Ce 3 + : BaF 2 precursor nanoparticles prepared by the co-precipitation method were uniform and have a average size of 25 nm. The highest transmittance of the ceramic was 77% at the wavelength of 2300 nm. The PL (photoluminescence) spectrum showed that the 5d–4f transition of Ce 3 + : BaF 2 transparent ceramic is located at 340 nm. X-ray excited luminescence exhibited only one violet peak at 392 nm. Scintillation decay time measurements showed only a slow component of 437 ns under 662 keV gamma excitation.
研究领域:
材料科学
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光学工程
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高影响因子
Catalysts
·
2021
·Vol. 11
·期 11
·1268
·
IF 4.146
Shucheng Wang,Chuanzhao Wang,Houlin Yu,Wei Yu,Yongnan Liu,Wucan Liu,Feixiang Zhou,Wanjin Yu,Jiuju Wang,Jianjun Zhang,Wenfeng Han
A BaF(p-BDC)0.5catalyst was prepared by solid state reaction at room temperature with Ba(OH)2as precursor, NH4F as F source, and H2(p-BDC) as organic ligand. The calcined samples were used as catalysts for dehydrochlorination of 1-chloro-1,1-difluoroethane to generate vinylidene fluoride (VDF) at 350 °C. Commercial production of VDF is carried out at 600–700 °C. Clearly, pyrolysis of the BaF(p-BDC)0.5catalyst provided a promising way to prepare VDF at low temperatures. Prior to calcination, the activity of the BaF(p-BDC)0.5catalyst was low. Following calcination at high temperatures, BaF(p-BDC)0.5decomposed to BaF2and BaCO3, and then the catalyst was chlorinated and fluorinated to BaClF, which showed high activity and stable VDF selectivity for dehydrochlorination of 1-Chloro-1,1-Difluoroethane to VDF.Keywords:barium fluoride;catalytic pyrolysis;dehydrochlorination;1-chloro-1,1-difluoroethane;vinylidene fluoride
研究领域:
化学工程
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材料科学
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DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Li Li,Ruoning Guo,Jie Gao,Jie Liu,Zhiwei Zhao,Xin Sheng,JunYu Fan,Fuyi Cui
Perfluorooctanoic acid (PFOA) is a representative persistent organic pollutant and its disposal by mechanochemical (MC) technology emerges in recent years. However, degradation mechanism of PFOA especially rupture of C−F bonds during MC process is still unclear. Therefore, we innovatively employed barium titanate as co-milling reagent in MC system to disclose an electron-dominated reduction process. By stimulating piezoelectric effect of BaTiO 3 under MC impact, free electrons were generated. The results implied more than 95.00% degradation and 60.00% defluorination efficiency were obtained after 6 h′ ball milling. DPPH• was used as probe to confirm the existence of piezo-excited electrons, which were further verified to be major reactive species by atmosphere experiments. Thus, PFOA destruction was dominated by reduction process, characterizing by breakage of C−F bonds induced by electrons. Accordingly, the fate of organic fluorides was explored and BaF 2 was identified as final product. The cleavage of carboxyl group initiated PFOA decomposition, following by successive removal of CF 2 groups and elimination of F − . Moreover, the practical experiments and reusable trials implied promising application of this method. Overall, this paper provides a novel perspective for reductive decomposition of PFOA by MC technology and reveals the major role of electrons during reaction process.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
LANGMUIR
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2023
·
IF 3.9
Yang Wu,Junhao Jing,Xiaojiang Li,Wenjian Yue,Jie Qi,Na Wang,Hongsheng Lu
A new form of surfactant-free microemulsion (SFME) including hydrophobic deep eutectic solvent (HDES)/ethanol/water was constructed based on its CO2 response, and three regions, that is, HDES-in-water (HDES/W), bicontinuous (B.C.), and water-in-HDES (W/HDES) regions, were recognized. It is anticipated that SFMEs with tunable microstructures have outstanding applications as nanoreactors in reaction processes. The feasibility of preparing nanoparticles from HDES/ethanol/water SFME using barium fluoride (BaF2) as a model nanoparticle was investigated. HDES-based microemulsions benefit from HDES’s excellent properties (novel, low toxicity, CO2-responsive, easy availability) and have potential in universal reactions, drug delivery, advanced material fabrication, etc. In this research, HDES-based microemulsions were prepared using HDES as the oil phase. Phase equilibria and microstructure were investigated using a ternary phase diagram, UV spectrophotometry, and the conductivity method. The CO2 switchable characteristics of the HDES-based microemulsions were investigated. HDES-based microemulsions were proposed as nanoreactors for the synthesis of barium fluoride nanomaterials. The microemulsion structure can modulate the size, morphology, and physicochemical properties of the nanoparticles through the CO2 switchable properties. It is argued that nanoreactors constructed with versatile HDES will offer a new direction for creation of cutting-edge scientific applications.
研究领域:
材料科学
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纳米技术
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化学工程
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PubMed
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2024
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IF 3.9
Chenglong Ji,Yuncai Gao,Yulu Wang,Ran Li,Yu-e Shi,Zhenguang Wang,Yongqing Zhai
Graphical The dim and short-lived RTP emissive organic molecules were transferred into afterglow materials with an emission efficiency of 45 % and emission lifetime of 1.9 s, through a straightforward coordination and in-situ precipitation reaction. The coordination reaction reduced the energy gaps between singlet and triplet states and stabilized the excited states of the guest molecules. Developing efficiency and long-lived room-temperature phosphorescence (RTP) materials through straightforward methods is highly desired. In this work, a stepwise stabilization strategy was proposed by the coordination and in-situ precipitation reactions among organic precursors, inorganic cation and anions, producing room-temperature phosphorescence materials with high emission efficiency (phosphorescence quantum yield of 45 %). Structural and photophysical characterizations revealed the coordination reaction reduced the energy gaps between singlet and triplet states and stabilized the excited states of the guest molecules. The in-situ precipitation reaction produced a solid matrix, which provided isolated environments for protecting the excitons from quenching. The applications of RTP materials in information encryption were demonstrated. The presented results provided a new clue for producing RTP materials, and extended their applications in wide fields.
研究领域:
材料科学
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光学
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PubMed
高影响因子
INORGANIC CHEMISTRY
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2025
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IF 4.7
Yunjie Bai,Cheng Chen,Mingye Han,Bingbing Zhang,Ying Wang
Borate materials possess diverse crystal structures and exhibit outstanding physical properties, making them highly suitable for optical applications. In this work, two new compounds, α-BaGdBO3F2 and β-BaGdBO3F2, were synthesized by the high-temperature solid solution method and a temperature-controlled phase transition from α-BaGdBO3F2 to β-BaGdBO3F2 was observed. In the crystal structures of α-BaGdBO3F2 and β-BaGdBO3F2, the [BO3] basic building unit and the [GdO6F2] polyhedra are interconnected to form a complex three-dimensional network. The title compounds exhibit good thermal stability, a short ultraviolet cutoff of 274 nm, and a moderately large birefringence (0.072 and 0.059@ 546 nm). The DFT calculations also reveal that β-BaGdBO3F2 could be a potential nonlinear optical (NLO) material. The results indicate that α-BaGdBO3F2 and β-BaGdBO3F2 are promising candidates for UV birefringent and NLO crystal materials.
研究领域:
材料科学
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光学
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PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
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2025
·
IF 3.5
Shuaikun Li,Yanhong Wang,Haibo Li,Hang Liu,Yun Lv,Hongcheng Lu
A novel magnetic alkaline-earth chromium fluoroiodate Ba 2 CrIO 3 F 6 has been successfully synthesized via the hydrothermal method and characterized for its structure and physical properties by single crystal X-ray diffraction, attenuated total reflection (ATR) infrared spectroscopy, UV-vis-NIR spectroscopy, thermal stability, as well as magnetic susceptibility, and specific heat. The compound Ba 2 CrIO 3 F 6 contains the [CrIO 3 F 6 ] 4- spin chains which are further separated by nonmagnetic Ba 2+ cations. The magnetic susceptibility results show no long-range magnetic order down to 2 K, which are further confirmed by specific heat measurement. The positive Weiss temperature and the increase of χT - T curve at low temperature both suggest the magnetic exchange interactions through the Cr 3+ −IO 4 F−Cr 3+ pathway are unexpectedly ferromagnetic. Our work illustrates that it is promising to use the IO x F y anion group for the design and construction of novel magnetic materials with ferromagnetic exchange interactions for potential spintronics device applications.
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Small
·
2025
·Vol. 21
·期 38
·e05477
·
IF 12.1
Sheng Zhang,Xiuxia Yang,Jianqiang Xiao,Junxiao Wu,Xingliang Luo,Siyuan Luo,Huaiqiang Ba,Yuan Xue,Jie Yu,Xuhui Xu
Mechanoluminescence (ML) refers to the unique phenomenon that converts mechanical energy into optical energy. However, at present, there are many kinds of ML generation mechanism models, such as piezoelectric type, triboelectric type, trap-related type, etc., which seriously affect the understanding of the intrinsic mechanism models. Herein, a rare-earth-doped fluoride glass ceramic (Ba 2 LaF 7 :Yb 3+ glass-ceramic, BYG) is developed capable of dual-mode near-infrared ML (NIR ML) via triboelectric and frictional heat pathways. The triboelectric-induced ML arises from interfacial charge transfer between the glass and organic polymer matrices, directly exciting Yb 3+ emission centers. In contrast, frictional heat-induced ML involves the carriers released from oxygen vacancies generated by X-ray irradiation. Such dual-mode NIR ML demonstrates a robust linear correlation with applied stress, enabling the development of a visualized bright-field sensing platform for real-time monitoring of triboelectric potentials and frictional temperatures. Furthermore, this work not only advances the mechanistic understanding of ML but also provides a versatile strategy for indirect optical sensing in ambient environments.
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高影响因子
ACS Applied Electronic Materials
·
2025
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IF 4.7
Xin Yan,Sijie Su,Zitao Chen,Yongchao Jia,Yajie Li,Enhai Song,Qinyuan Zhang
The development of highly efficient near-infrared-II (NIR-II) emission phosphors is crucial for advancing compact light sources and their emerging applications. However, the discovery of target phosphors remains a major challenge. Herein, a high-efficiency apatite phosphor, Ba10(PO4)6F2:Mn5+, peaking at 1171 nm with a full width at half-maximum of 11 nm, is synthesized under an oxygen atmosphere. Benefiting from the crystallographic site confinement and oxygen partial pressure control in stabilizing pentavalent manganese, the phosphor exhibits a record internal quantum efficiency (IQE) of 84.2% and external QE of 56%, alongside good thermal stability. By combining Ba10(PO4)6F2:Mn5+ with a red light-emitting diode (LED) chip, a phosphor-converted compact LED with an NIR-II output power of 40.86 mW at 300 mA and a high photoelectric conversion efficiency of 6.82% is presented, demonstrating applications in nondestructive testing, etc. Furthermore, the different temperature-dependent behaviors of the zero-phonon line emission (1171 nm) and vibrational sidebands (1224/1289 nm) of Mn5+ in Ba10(PO4)6F2:Mn5+ enable the fabrication of a high-efficiency fluorescence intensity ratio optical fiber temperature sensor, exhibiting a maximum relative sensitivity value of 0.518% K–1 at 373 K. This work offers some insights into Mn5+-activated high-efficiency NIR-II emission phosphors and their potential for temperature sensing and compact light source applications.
研究领域:
材料科学
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光学材料
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光子学
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固态照明
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温度传感
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发光材料
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DOI
高影响因子
Inorganic Chemistry Frontiers
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2024
·
IF 6.1
Cheng Chen,Danyang Dou,Yunjie Bai,Bingbing Zhang,Ying Wang
The investigation of birefringent materials is predominantly focused on π-conjugated systems; however, a large band gap or deep ultraviolet (DUV) transmittance cannot be guaranteed. In this work, we propose an extended π-conjugated strategy to increase the birefringence while keeping the large band gap. In the scheme, two new fluoroaluminoborates, BaAlB3O6F2 and BaAl2(B3O6)2F2, are synthesized by combining the [BO3] group with the [AlO4F2] group and the [B3O6] group with the [AlO3F] group through a rational structural design. The experimental results indicate that both BaAlB3O6F2 and BaAl2(B3O6)2F2 exhibit shorter UV cutoff wavelengths (<200 nm) and larger birefringence (Δn > 0.07@546 nm). Notably, this is a new finding in the Ba–Al–B–O–F system since the discovery of the well-known nonlinear optical crystal BaAlBO3F2. In comparison with BaAlBO3F2, BaAlB3O6F2 and BaAl2(B3O6)2F2 exhibit a markedly elevated birefringence (0.0418 vs. 0.087/0.105 at 546 nm). Furthermore, BaAl2(B3O6)2F2 exhibits the largest band gap (7.87 eV) of all known F-containing aluminoborates. This work not only identifies two potential DUV birefringent materials, but also proposes a novel design approach for reconciling the conflicting properties between birefringence and bandgap.
研究领域:
材料科学
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光学
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高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Wengao Pan,Qingping Lin,Lili Xiao,Shihao Feng,Ying Li,Jie Gao,Pengfei Yue,Guoshang Zhang
Perovskite structural LiBaF 3 ceramics with excellent microwave dielectric properties were synthesized using traditional solid-state method. By regulating the sintering temperatures from 600 °C to 675 °C, LiBaF 3 ceramics exhibit tunable dielectric constant ( ε r ) from 12.42 to 13.72, adjustable Q × f value from 55000 GHz to 73000 GHz, and regulable temperature coefficient of resonance frequency ( τ f ) from −36.78 ppm/°C to −34.68 ppm/°C. The properties are strongly associated with the density, and can be further optimized by 0.5 wt%TiO 2 addition ( ε r = 14.43, Q × f = 56000 GHz, τ f = -1.26 ppm/°C). The LiBaF 3 ceramics also exhibit excellent compatibility with Ag and Al electrodes. Furthermore, relationships between multiscale structures and microwave dielectric properties of the ceramics were revealed. Oxidation behaviors between LiBaF 3 and O 2 would result in the lattice shrinkage, the introduction of defect level, the decrease of bandgap and density, and then deteriorating the microwave dielectric properties. All the findings make the LiBaF 3 ceramic a promising candidate for ULTCC application, and may facilitate the development of other novel microwave dielectric materials.
研究领域:
材料科学
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电子工程
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高影响因子
危险品化学品经营许可证（带存储）