RESEARCH ON CHEMICAL INTERMEDIATES
·
2018
·Vol. 44
·期 5
·3061-3079
·
IF 1.674
Wang Junxiu,Chen Kuan,Shen Yi,Wang Xi,Guo Yongfu,Zhou Xiaoji,Bai Renbi
Abstract To heighten the absorption to visible light and improve photocatalytic degradation to organic pollutants, a novel photocatalyst of m-Bi 2 O 4 /Bi 2 O 2 CO 3 was constructed through a facile hydrothermal method. The crystal structure, optical properties, morphology, composition and photocatalytic ability of the photocatalysts were characterized via X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, field emission scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscope (TEM), high resolution TEM, selected-area electron diffraction and X-ray photoelectron spectroscopy technologies. The as-prepared photocatalysts could efficiently degrade rhodamine B and mixed dye under visible light. The removal rate was up to 95.3% within 50 min. The results demonstrated that m-Bi 2 O 4 /Bi 2 O 2 CO 3 photocatalysts showed outstanding photocatalytic degradation ability compared to the single photocatalyst with the narrow band gap. In addition, photocurrent response tests certified that the heterostructure of the photocatalysts effectively accelerated the separation and migration of photo-induced electrons and holes. Active species trapping experiments indicated that holes (h + ) and superoxide radical (•O 2 − ) were major species rather than hydroxyl radicals (•OH) during the degradation process of organics. According to the test results, a probable photocatalytic mechanism was proposed. This work provided a new and efficient photocatalyst for environmental remediation and water treatment. Graphical Abstract
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2011
·
IF 2.089
Baimei Yang,Hui Wan,Guofeng Guan
Isobaric binary vapor–liquid equilibrium (VLE) data for 1-butanol + ethylbenzene, or o-, or m-, or p-xylene and isobaric quinary VLE data for 1-butanol + ethylbenzene + o-xylene + m-xylene + p-xylene are measured at 101.33 kPa using a modified Rose cell with circulation of both phases. The four binary systems of 1-butanol + ethylbenzene, or o-, or m-, or p-xylene exhibit minimum boiling azeotropes, and the composition of the azeotropes are reported. The VLE data for the four binary systems are checked to meet rigorous thermodynamic consistency by Herington method and the point-to-point test of the Fredenslund method. The nonideality in vapor phase of the measured binary systems is analyzed through calculating fugacity coefficients. Combined with the Hayden–O'Connell (HOC) equation, the VLE data for 1-butanol + ethylbenzene, or o-, or m-, or p-xylene are well-correlated by the nonrandom two-liquid (NRTL), universal quasichemical activity coefficient (UNIQUAC), and Wilson equations. The NRTL model parameters obtained from correlation are used to predict the VLE data of the quinary system. According to the average absolute deviation values, the obtained quinary predicted values are in good agreement with the experimental values.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2025
·Vol. 36
·期 19
·1-11
·
IF 2.8
Li Canglong,Wen Kexin,Zhang Bing,Chen Jie,Niu Xinshuai,Zou Boyuan,Lu Xuechi,Yang Wenqian
The structure, magnetic behavior and magnetocaloric performance in heavy rare–earth based compounds Tb 2 M TiO 6 ( M = Co, Ni, Cu) have been experimentally investigated in this work. The structural analysis indicates that Tb 2 CoTiO 6 and Tb 2 NiTiO 6 crystallize in a monoclinic double perovskite structure, while Tb 2 CuTiO 6 forms a hexagonal layered structure. The magnetic measurements reveal that the samples show high magnetic reversibility within a wide temperature range. The high-temperature Curie–Weiss fitting suggests that the antiferromagnetic coupling between RE 3+ and RE 3+ is dominant at low temperatures. The Arrott-plots imply that the magnetic transition in Tb 2 M TiO 6 is of second–order nature according to the Banerjee’s criteria. The magnetic entropy change − Δ S M is evaluated to be 10.7, 16.2 and 13.2 J kg −1 K −1 for Tb 2 CoTiO 6 , Tb 2 NiTiO 6 and Tb 2 CuTiO 6 at 4 K and magnetic field change Δ H = 6 T, respectively. The work suggests that the lack of 3 d –3 d coupling in the design of double perovskites is one of the potential approaches for developing low-temperature magnetic refrigeration materials.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Tian Tang,Lyumeng Ye,Yanrong Chen,Jingyu Xue,Xiaoqiang Shen,Jinfei Chen,Fiona Hammond Quarcoo,Vladislav Rac,Vesna Rakić,Xinbao Li,Xuesen Du
The unique interface synergistic catalytic properties for metal oxide-supported catalysts have long been explored in several critical heterogeneous catalytic processes (e.g., CO oxidation reactions). However, interfacial synergistic catalysis is still a hitherto undescribed mechanism due to the lack of direct evidence at the atomic level. Thereinto, the CuO x -supported CeO 2 (CuO x /CeO 2 ) catalyst is a typical case. Herein, a combination study including representative theoretical calculations, in situ DRIFTS spectra and tailored molecular probe experiments supports a new carbonate-interface mediated Mars-van Krevelen (M−vK) mechanism for CO oxidation, i.e., CO molecules form carbonate intermediate species directly between spatial proximity (2.99 Å) double lattice oxygen sites with low oxygen vacancies formation energy (E form O v = 0.82 eV/0.83 eV) at the copper−ceria interface. The reaction energy barrier of this process is 0.32 eV, much lower than the 1.23 eV of the conventional M−vK mechanism. Besides, the spatial effect of double oxygen vacancies (O v ) generated by the depletion of intermediate carbonate species promotes the sustained and dynamic activation of O 2 , hence facilitating the efficient operation of the M−vK mechanism at low temperatures.
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FUEL
·
2024
·
IF 6.7
Xi Li,Haiyong Wang,Kingdom Alorku,Jin Wang,Longlong Ma,Ying Xu
Efficient hydrogenolysis of C-O bonds in lignin offers a promising pathway for producing high-value-added biofuels and chemicals. However, designing an easily synthesized, highly active catalyst for this process remains a challenge. In this paper, a series of Ni-M(Pd, Pt, Ru)/C catalysts were prepared and synergized with NaOH to produce aromatic compounds from β-O-4 model compound (MC). Among the catalyst systems, Ni-0.25 % Pd/C-NaOH completely converted β-O-4 MC at mild conditions (150 °C, 2 MPa H 2 , 3 h) to produce monomers with a yield of 95.6 wt% and excellent selectivity of the bond-breaking products as high as 85.5 %. Recycling tests showed that the Ni-0.25 % Pd/C catalyst remained stable after five cycles, with high activity and without the need for a further reduction before runs. Further, the catalytic system has proven to exhibit high activity for the cleavage of other types of lignin MC, such as 4-O-5, α-O-4, β-O-4 and ether bond (diphenyl ether, benzyl phenyl ether, Guaiacolylglycerol-β-guaiacol ether, benzyl ether) and also effective for lignin from enzymatic cleavage (LEC). Hydrogenolysis of LEC achieved a monomer yield of 34.5 wt%; the molecular weight (555 g/mol) of the hydrogenolysis oligomer was significantly reduced compared to LEC (2872 g/mol). The highly active and stable Ni-0.25 % Pd/C-NaOH catalytic system provides a promising pathway for the efficient hydrogenolysis of lignin and lignin model compounds to produce high-value biofuels and chemicals.
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REPRODUCTIVE TOXICOLOGY
·
2024
·
IF 3.3
Huilei Chen,Yang Liu,Yue Huang,Pin Zhang,Danli Du,Wenhua Yu,Caiyun Wu,Hongzhen Ruan,Ping Zhou,Zhiming Ding,Huifen Xiang
Bisphenol M (BPM), an alternative to bisphenol A (BPA), is commonly utilized in various industrial applications. However, BPM does not represent a safe substitute for BPA due to its detrimental effects on living beings. This research aimed to assess the influence of BPM exposure on the in vitro maturation of mouse oocytes. The findings revealed that BPM exposure had a notable impact on the germinal vesicle breakdown (GVBD) rate and polar body extrusion (PBE) rate throughout the meiotic progression of mouse oocytes, ultimately resulting in meiotic arrest. Investigations demonstrated that oocytes exposure to BPM led to continued activation of spindle assembly checkpoint. Further studies revealed that securin and cyclin B1 could not be degraded in BPM-exposed oocytes, and meiosis could not realize the transition from the MI to the AI stage. Mechanistically, BPM exposure resulted in abnormal spindle assembly and disrupted chromosome alignment of oocytes. Additionally, abnormal positioning of microtubule organizing center-associated proteins implied that MTOC may be dysfunctional. Furthermore, an elevation in the acetylation level of α-tubulin in oocytes was observed after BPM treatment, leading to decreased microtubule stability. In addition to its impact on microtubules, BPM exposure led to a reduction in the expression of the actin, signifying the disruption of actin assembly. Further research indicated a heightened incidence of DNA damage in oocytes following BPM exposure. Besides, BPM exposure induced alterations in histone modifications. The outcomes of this experiment demonstrate that BPM exposure impairs oocyte quality and inhibits meiotic maturation of mouse oocytes.
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PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2024
·
IF 3.2
Shu Li,Zhanmin Cao,Zhongnan Guo,Wenxia Yuan,Fan Sun,Hongmei Wang
This article reports a new perovskite compound Ca 6 Sb 2 O 11 . The X-ray powder diffraction technique was used to analyze its crystal structure. The results show that Ca 6 Sb 2 O 11 has a tetragonal structure with the I 4/ m space group, and the lattice parameters are a = b = 5.658 (1) Å, c = 7.984 (1) Å, α = β = γ = 90°. It exhibits a typical A 4 B' 2 B″ 2 X 12- x anoxic multi-perovskite structure with rock-salt ordering of the B-site cations. The compound's chemical composition and valence states were characterized through scanning electron microscopy-energy dispersion spectrum (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). The presence of oxygen vacancies was confirmed by electron paramagnetic resonance (EPR) spectroscopy. A chemical and structure transition temperature and the full melting temperature of Ca 6 Sb 2 O 11 were measured, with values of 1515 ± 3 K and 1720 ± 3 K, respectively. The density functional theory (DFT)-electron structure calculation results show that Ca 6 Sb 2 O 11 is an indirect wide-band gap (∼4.47 eV) semiconductor material , which agrees well with the experimental value (∼4.38 eV) obtained through diffuse reflection spectroscopy (DRS). Moreover, the top of the valence band and bottom of the conduction band are mainly contributed to by O-2p and Ca-3d states, respectively.
研究领域:
材料科学
·
固体化学
·
计算物理
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Polymer Chemistry
·
2016
·Vol. 7
·期 29
·4717-4727
·
IF 5.687
Qingfu Ban,Jie Kong
Well-defined hyperbranched polymers with long-chain backbones between the branched points (HyperMacs) are an emerging issue in topological polymers. Owing to the difficult discrimination of branching points interfered with or overlapped by long-chain backbones in nuclear magnetic resonance signals, the fine identification and quantitative characterization of intramolecular cyclization and the calculation of the degree of branching for HyperMacs are always challenges. In this contribution, a convenient expression of the macro-cyclic index (m-CI) was presented and deduced as the ratio of NA/NB of HyperMacs to that of their completely intramolecular cyclized analogues. The physical meaning of m-CI is the similarity of HyperMacs to their completely cyclized analogues. Accordingly, a m-CI closer to 1 means a high degree of intramolecular cyclization, even complete cyclization. The experimental validation via model polymers indicates that m-CI is a facile parameter to analyze intramolecular cyclization of HyperMacs. The increase of the chain length of the backbones between branched points can enhance intramolecular cyclization of HyperMacs accompanied with the increase of the m-CI value. As an original contribution to polymer science, the presentation of m-CI overcomes the difficult problem of quantitative characterization of intramolecular cyclization in long-chain hyperbranched polymers, which is helpful for a good understanding of their relationship between topological structures and properties.
研究领域:
高分子科学
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材料科学
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化学工程
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高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2021
·
IF 3.975
Min Zhong,Xiuming Wu,Chen Shu,Yuling Wang,Xingyi Huang,Wei Huang
A series of polyimides (PIs) containing a bulky side group of m -trifluoromethyl phenyl was synthesized via a high-temperature one-step polycondensation of 4-[3′,5′-bis(trifluoromethyl)phenyl]-1,3-phenylenediamine ( 2 ) and various aromatic dianhydrides. The weight-averaged molecular weights ( M w ) of the resulting PIs are between 3.92 and 8.36 × 10 4 g mol −1 with the M w / M n of 1.77–2.09. They are soluble in common organic solvents and easily processed into flexible films by the blade coating of PI solution. At room temperature , the dielectric constants ( k ) of these PI films are lower than 3.04 at 1 MHz and 2.87 at 10 GHz, especially the k of 2 -6FDA film is low to 2.66 at 1 MHz and 2.38 at 10 GHz. The breakdown strength of the resulting PI films (thickness: 10 ± 1 μm) is in the range from 461 to 523 kV mm −1 . Meanwhile, these PI films also show good thermal stability (5 wt% weight-loss temperature in the range of 521–571 °C under N 2 ; glass transition temperatures of 266–307 °C) and mechanical properties (tensile strength of 70.8–103.3 MPa, tensile modulus of 1.3–2.2 GPa, elongation at break of 9.1–10.8%). The average transmittance of these PI films (around 20 μm) is above 80% in the visible light region (400–760 nm). Such attractive comprehensive properties make these PIs as potential candidates for application in microelectronics industry.
研究领域:
材料科学
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高分子化学
·
电子材料
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高影响因子
Catalysts
·
2022
·Vol. 12
·期 9
·955
·
IF 4.501
Beilei Cui,Hua Wang,Qingfeng Ge,Xinli Zhu
A series of rutile TiO2-supported Ni catalysts with varying Ni sizes were prepared and reduced at 650 °C to explore the effect of Ni size on the strong metal–support interactions (SMSI) and its consequences on the hydrodeoxygenation (HDO) of m-cresol at 350 °C and atmospheric pressure. When the Ni size increases from 4 to 29.1 nm, the SMSI becomes stronger, e.g., the thickness of the TiOxoverlayer and the coverage extent of TiOxon the Ni particle surface increase. Direct deoxygenation to toluene is the dominant pathway on Ni/TiO2catalysts with varying Ni loadings, with almost no CH4being formed. These results indicate that the TiOxoverlayer significantly alters the property of Ni. That is, the C-C hydrogenolysis activity on bare Ni is completely inhibited due to SMSI, while the deoxygenation activity is improved at the Ni-TiOxinterfacial perimeter sites. Meanwhile, the turnover frequency of HDO on small Ni particles of 4 nm is > 2 times higher than that on large Ni particles of 29.1 nm, indicating that the small Ni particle with moderate SMSI appears to be optimal for the direct deoxygenation of m-cresol to toluene. The results suggest HDO activity may be enhanced by tuning the metal particle size and SMSI degree.Keywords:Ni/TiO2;rutile;strong metal-support interactions;m-cresol;hydrodeoxygenation
研究领域:
催化
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化学工程
·
材料科学
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2018
·
IF 2.196
Jun Wang,Jie Ou,Xueni Sun,Xiangjun Tong,Ben Gao,Chunxiang Huang,Hui Shao,Yixin Leng
Measurements of isobaric vapor–liquid equilibrium (VLE) results for binary systems of m-cresol (MC) + diisopropanolamine (DIPA) and 2,6-dimethylphenol (DMP) + DIPA and the ternary system of MC + DMP + DIPA were conducted at the pressure of 20.0 kPa. The binary VLE experimental data showed that DIPA had stronger interaction with MC than DMP. The ternary system experimental VLE data showed that DIPA could improve the relative volatility of DMP to MC. The binary experimental data were checked by using Herington area and point test methods, and the checked results were thermodynamically consistent. Meanwhile, the VLE data were correlated by Wilson, nonrandom two-liquid, and universal quasichemical models, and the binary energy interaction parameters for these models were obtained. These activity coefficient models were used to predict the ternary system VLE data. The predictive results suggested that the Wilson model had the best prediction.
研究领域:
化学工程
·
物理化学
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高影响因子
Environmental Science-Advances
·
2022
·Vol. 1
·期 3
·365-379
·
IF 0
Wenli Qin,Xinyi Zhang,Zefei Chen,Xueya Liu,Manqing Ai,Pingping Zhang,Ying Ye,Zengling Ma
Meso–macroporous MFe2O4@CMT (M = Ni, Co) catalysts were synthesized by coating carbon microtubes (CMTs) employing a calcination method. The obtained materials NiFe2O4@CMT (PCNF) and CoFe2O4@CMT (PCCF) were characterized via X-ray powder diffraction (XRD), pore structure analysis, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The electromagnetic (EM) wave absorption of catalysts was measured and it was found that the maximum reflection loss value of PCCF and PCNF was about −41.50 dB at a thickness of 1.85 mm and −24.70 dB at a thickness of 6.55 mm, respectively. The composite catalysts were prepared for the microwave (MW)-induced Fenton-like catalytic degradation of dimethyl phthalate (DMP). The microwave catalytic activity of PCNF was higher than that of PCCF, which was closely related to its higher concentration of active species, better microwave-absorbing ability and high interaction between NiFe2O4 and CMT. Moreover, the degradation kinetics could be well-fitted by the pseudo-first-order kinetic model. With an increase in the MW power, initial pH, catalyst dosage, and H2O2 concentration, the DMP degradation rate initially increased and then decreased, while it declined continuously with an increase in the initial DMP concentration. The introduction of metal oxides increased the mobility of the surface oxygen, playing a crucial role in the generation of surface oxygen species. The catalysts maintained high stability after five reaction cycles. The overall findings provide new insight into PCCF and PCNF under MW irradiation for the degradation of DMP and other relevant organic pollutants.
研究领域:
环境科学
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催化材料
·
化学工程
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