INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2026
·
IF 3.9
Shuangfu Wang,Yudong Li,Weizhong Zheng,Weizhen Sun,Ling Zhao
Pyromellitic acid (PMA) is a critical monomer in the synthesis of high-performance polyimides (PIs). A viable approach for the preparation of PMA is the synthesis of durene (DR) by liquid-phase oxidation using a Co/Mn/Br catalyst and acetic acid/water as solvents. Due to interaction between the transition metals Co/Mn and PMA, the catalytic effect is diminished, restricting industrial application of the liquid-phase oxidation method in the production of PMA. Based on the catalyst deactivation mechanism, the effects of different bromine sources, catalyst concentrations, solvent ratios, temperatures, and water contents on the liquid-phase oxidation of DR to PMA were systematically investigated in this work. A deactivation mechanistic model was developed covering DR, PMA, and other pivotal intermediates. Using hydrogen bromide as the bromine source and under conditions of a high solvent ratio, the yield of PMA was enhanced from 34.25 to 78.13 mol %. The kinetic model was utilized to conduct a comprehensive investigation into the impact of catalyst concentrations, temperature, and water content on the reaction and deactivation process. It was determined that the initiation of the DR oxidation chain is a rate-determining step and that the reaction rate increases while the deactivation rate decreases under high temperature and high-Co conditions. Furthermore, it is demonstrated that the optimum water content for the yield of PMA is 5%, with a concomitant slower deactivation reaction rate constant. Hopefully, the results obtained in this work can provide valuable insights into the liquid phase oxidation of polyalkyl aromatic hydrocarbons.
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高影响因子
Frontiers in Physiology
·
2017
·
IF 4.134
Jiang Jianru,Xu Yili,Lin Xinda
Ovarian development plays an important role in the life history of insects and is crucial for control of the insect population. The metamorphosis of an insect is precisely regulated by the interaction of the juvenile hormone and ecdysone. To understand the role of NlBr and NlKr-h1 in ovary development, we used RNA interference (RNAi) to down-regulate the expression of Broad-Complex (Br) and Krüppel homolog 1 (Kr-h1), two important down-stream transcription factors of juvenile hormone and ecdysone signaling. We further investigated their effects on metamorphosis and ovary development. The results showed that both NlBr and NlKr-h1 are induced by ecdysone. The down-regulation of NlBr and NlKr-h1 alone or together by RNAi is more effective than the topical application of ecdysone on the number of ovarioles, suggesting the necessity of NlBr and NlKr-h1 in determining the number of ovarioles. The ovarian grade was significantly increased/decreased by the topical application of ecdysone and down-regulation of NlBr and NlKr-h1. The pre-oviposition period was also increased. When NlBr and NlKr-h1 were down-regulated together, the ovary grade was not significantly different compared to the control (dsGFP), indicating that the development of the ovary is under the control of both NlBr and NlKr-h1. The interaction between the NlBr and NlKr-h1 on the number of ovarioles and the development of the ovary indicates cross-talk between both juvenile hormone and ecdysone signaling at the transcription level in the brown planthopper. Both genes are nuclear transcription factors and may regulate signaling via down-stream genes. These results would help to both enhance the current understanding of the regulatory mechanism of the interaction between juvenile hormone and ecdysone signaling pathways during ovarian development and to design chemicals to control pests.
研究领域:
昆虫学
·
分子生物学
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DOI
PubMed
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
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2021
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IF 4.051
Zhihao Chen,Haiyang He,Zhuoqi Wen,Zhongjie Cui,Shiliang Mei,Dan Yang,Xian Wei,Wanlu Zhang,Fengxian Xie,Bobo Yang,Ruiqian Guo
Broadband emission Mn 2+ doped lead halide perovskites are deemed as promising phosphor materials for solid state white light-emitting-diodes (WLEDs). Herein, we report a facile gram-scale synthesis of Mn-doped CsPb(Br/Cl) 3 phosphors by doping MnCl 2 into CsPbBr 3 perovskite nanocrystals at room temperature. The obtained phosphors present dual-color emission with blue emission at 463 nm and red emission at 602 nm. Increasing MnCl 2 doping amount can enhance the red emission while more 3-Aminopropyltrimethoxysilane (APTMS) ligands can repress Mn related impurity and provide high stability. Further, two kinds of WLEDs (monocomponnet and two-component) are demonstrated. The monocomponent WLED exhibits warm white light under various driving currents (30 mA–150 mA), and the two-component WLED shows good chromatic performance close to ideal white light (0.33, 0.33), demonstrating their potential applications in WLED devices.
研究领域:
材料科学
·
光学工程
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高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 27
·13610-13618
·
IF 11.301
Qian Zhang,Xuqiang Liu,Nana Li,Bihan Wang,Quan Huang,Lin Wang,Dongzhou Zhang,Yonggang Wang,Wenge Yang
Sillen compounds with the general formula of PbBiO2X (X = Cl, Br, I) are frequently studied as photocatalysts, and have attracted widespread attention due to their degradation of organic contaminants and water oxidation under visible light irradiation. Among many photoelectric materials, the band gap has been reduced approaching to the optimum value by pressure (1.34 eV for photovoltaic materials according to the Shockley–Queisser limit), which is favorable to their photo-responsive applications. However, such enhanced properties are usually restored after the pressure is released. Here, by combining the pressure and chemical engineering tools, we discovered that the optimized structure and optical band gap of PbBiO2Br could be locked after compression–decompression treatment cycling by selecting appropriate elemental species. The pressure-induced strain retention in PbBiO2Br could be the cause of the structural and optical irreversible behavior. Moreover, the compression behavior and optical band gap under high pressure in the PbBiO2X system were studied systematically by in situ high pressure synchrotron X-ray diffraction, UV-vis absorption spectroscopy and resistivity experiments. Along with the enhanced photocurrent under compression, the PbBiO2X compounds under external pressure exhibited great potential for photocatalytic applications under solar light irradiation. In a suitable element category, the pressure-driven structural lock-in preserves its optical performance, opening up a new window for manipulating and filtrating better multifunctional materials.
研究领域:
材料科学
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凝聚态物理
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无机化学
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光催化
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功能材料
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DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2023
·Vol. 39
·期 4
·654-659
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IF 3.1
Zhu Xia,An Jiakun,Chen Gaoyu,Xing Chenyu,Bao Jianchun,Xu Xiangxing
Perovskite single crystals are prominent semiconductor materials due to their high carrier mobility, long carrier diffusion length, and large absorption coefficient. They can be used as optoelectronic functional materials for narrowband or broadband photodetectors. In this report, the photodetection band tunability was achieved by doping MAPbX 3 (MA=methylammonium, X=Cl/Br/I) perovskite single crystals with sub-nano carbon dots (MAPbX 3 -C). The sub-nano size and good dispersibility of the carbon dots ensured controllable doping. The absorption of the sub-nano carbon dots and trap states in the MAPbX 3 -C single crystals resulted in the special responsivity spectrum features.
研究领域:
材料科学
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光电子学
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半导体物理
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纳米技术
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光子学
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高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 12
·4728-4733
·
IF 4.569
Chunlan Tang,Wenhao Xing,Naizheng Wang,Jian Tang,Zheshuai Lin,Jieyun Wu,Wenlong Yin,Bin Kang
Inorganic metal chalcohalides are significant semiconductive materials for photovoltaics, photodetetion and infrared optics. Thus it is considerably rewarding to develop a new synthetic strategy to provide more degrees of freedom for atomic coordination to tune the optical and electronic properties of metal chalcohalides. In this work, the mixed-anion strategy is performed to synthesize two new metal chalcohalides Cs2InPS4X2 (X = Cl, Br) with mixed-anion structure by the reaction of InPS4 and CsX. Single-crystal X-ray diffraction analysis shows that they are isostructural and crystallize in the centrosymmetric space group P21/n, consisting of zero-dimensional structure [In2P2S8X4]4− (X = Cl, Br) built from tetrahedral [PS4]3− and octahedral [InS4X2]7− (X = Cl, Br) through edge-sharing, with Cs cations filling in intervening voids. The UV-vis-NIR diffuse reflectance spectroscopy measurement reveals that Cs2InPS4Cl2 and Cs2InPS4Br2 exhibit large optical bandgaps of 3.21 eV and 3.12 eV, respectively. The electronic structure calculations show that the bandgap mainly originates from the [InS4X2]7− (X = Cl, Br) mixed-anion groups. First-principles calculations indicate that the birefringence of Cs2InPS4Cl2 and Cs2InPS4Br2 is ∼0.08 and ∼0.05 at 2090 nm, respectively. Furthermore, thermal analysis reveals that the Cs2InPS4X2 (X = Cl, Br) are thermostable up to 400 °C. This discovery enriches the structural diversity of inorganic chalcohalides and provides an insight for the exploration of new semiconductive materials.
研究领域:
无机化学
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材料科学
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半导体物理
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晶体工程
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红外光学
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DOI
高影响因子
Materials Today Chemistry
·
2022
·
IF 7.613
J. Ding,X. Cui,Q. Ren,Y. Mao,J. Zhang,G. Zhou,X.-M. Zhang
Organic-inorganic metal halides have garnered extensive attention due to their versatile structures as well as fascinating optical properties , among which especially antimony halides are the focus of recent research. Herein, we design a series of novel zero-dimensional (0D) antimony halides of (C 13 H 14 N 3 ) 3 SbCl 6– x Br x ( x = 0, 3, 6) with bright and tunable broadband emissions from yellow (576 nm) to orange (600 nm), which are attributed to the triplet self-trapped excitons (STEs) of the six-coordinated [SbX 6 ] 3– (X = Cl − or Br − ) units. The role of halogens on their specific 3 P 1 → 1 S 0 transition is determined, wherein Cl/Br transmutation reveals a common law modulating photoluminescence behaviors. Furthermore, a new two-step compound technology is innovatively developed for performance optimization, enabling by incorporating the pristine antimony halides into polymethyl methacrylate (PMMA) with high transparency and strong moisture resistance . The composites (C 13 H 14 N 3 ) 3 SbCl 6– x Br x /PMMA ( x = 0, 3, 6) were fabricated through a demanding technology that significantly improve the processability and water stability of antimony halides while maintaining high photoluminescence quantum yields . This work not only proposes a method for halogen substitutions to tune emission, but also opens up a feasible research avenue for performance optimization in the multifunctional luminescence materials.
研究领域:
材料科学
·
光学
·
化学工程
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高影响因子
Journal of Herbal Medicine
·
2023
·
IF 2.3
Ying Liu,Xia Zhang,Huaiyu Cheng,Yifang Li,Guangxiong Zhou
ABSTRACT Introduction It has a long history to employ Macleaya cordata (Willd.) R. Br. (Papaveraceae) for the treatment of a variety of diseases in China. Chelerythrine, one of the major of M. cordata with detoxifying and anti-inflammatory effect, is reported to combat bacteria and fungus. This work aims to explore the effect of chelerythrine against fluconazole-resistant C. albicans and also illustrate its potential mechanism. Methods The microdilution method, following CLSI-M27-A3 was used to evaluate the effect of chelerythrine against fluconazole-resistant C. albicans. Meanwhile, biofilm viability was assessed by XTT assay and cell morphology was observed by inverted microscope. RT-qPCR and confocal laser scanning microscope were employed to detect the mRNA expression and DCFH-DA staining, respectively. Fluorescence intensity was quantified by flow cytometry. Results The total alkaloids extract of M. cordata significantly inhibited the viability of C. albicans, concentration of which in 64 μg/mL presented to 40% inhibitory effect . In addition, the MIC 80 for chelerythrine was 8 μM, whereas chelerythrine in 4 μM inhibited biofilm formation by 47.7%. Further studies revealed that chelerythrine reduced the hydrophobicity of cellular surface, inhibited hyphal growth, downregulated the expression of genes related to cAMP pathway, increased cellular permeability and promoted the production of reactive oxygen species (ROS). Conclusion Chelerythrine inhibited biofilm formation by decreasing CSH and inhibiting the cAMP pathway. Chelerythrine increased cellular permeability and promoted the production of reactive oxygen species, which leads to the cell death of fluconazole-resistant C. albicans .
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Molecular Catalysis
·
2023
·
IF 4.6
Lianyang Zhang,Yue Meng,Bo Xie,Zheming Ni,Shengjie Xia
The activity of single-crystal catalysts with different crystal faces varies greatly, and the construction of catalysts with highly exposed active facets is essential for the improvement of photocatalytic performance. In this paper, Cu 2 O (100) crystal facets were transformed into high degrade-active Cu 2 O (111) crystal facets by doping with halogen atoms Br for the photocatalytic degradation of tetracycline. The effect of the optimal Br/Cu 2 O ratio on the degradation activity was investigated by adjusting the amount of Br. Meanwhile, based on photocatalytic degradation performance tests, photoelectric performance characterization and theoretical calculations, it was found that the doped Br-Cu 2 O introduced impurity energy levels, reduced the band gap, broadened the absorption range of the photocatalyst under visible light, and enhanced the oxidation capacity and the rate of photogenerated electron leap. In addition, the highly active Cu 2 O (111) crystal surface facilitates the adsorption of oxygen to generate superoxide radicals and promote the photocatalytic reaction. The synergistic effect of these two aspects promotes the efficient degradation of tetracycline by Br-Cu 2 O. This work provides a promising idea for the design and construction of highly efficient active surface highly exposed photocatalysts.
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高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Qiang Huang,Changqing Tian,Junan Lai,Fei Qi,Nan Zhang,Jiaxin Liu,Zhiyu Liang,Daofu Wu,Xiaosheng Tang
In response to calling for a sustainable and carbon-neutral economy, the conversion of CO2 to useful chemicals using the solar energy is a potential tactic to relieve the global energy dilemma and environmental issues, which has been a hot topic so far. Recently, the lead halide perovskites as novel photocatalysts have attracted researchers’ interests. However, they generally encounter poor stability and lead toxicity, restricting their large-scale practical applications. Here, the lead-free Cs2TeX6 (X = Cl, Cl0.5Br0.5, Br, Br0.5I0.5, and I) perovskite microcrystals with strong stability were prepared and used to realize the CO2 photocatalytic reduction efficiently. The prepared Cs2TeBr6 microcrystals delivered stronger photocatalytic ability than many previously reported photocatalysts, with the CO and CH4 yields of 308.63 and 60.42 μmolg–1, respectively, under 3 h of illumination. The presented strategy in our work provides new ideas of designing and preparing efficient and practical CO2 reduction photocatalysts based on nonleaded and high-stability halide perovskites.
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DOI
PubMed
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Mantong Xue,Jianfei Sun,Xintong Li,Jianlei Qi,Qinqin Xu,Jianzhong Yin
Emissions of carbon dioxide can lead to the greenhouse effect, causing global warming and so on. conversion of carbon dioxide into high-value chemicals through catalysis, which is an effective method to successfully curb carbon emissions and prevent the greenhouse effect. Among them, CO 2 chemical synthesis of cyclic carbonate is one of the important way. In this paper, a new type of supported ionic liquid catalyst (GO-[DBU][Br]) was synthesized by one-pot method. Subsequently, the GO-[DBU][Br] was applied to the cycloaddition reaction of CO 2 in batch reaction and fixed bed continuous reaction, respectively. The stability of the catalyst was also explored, the GO-[DBU][Br] was easily separated and reused at least 5 times without significant loss of catalytic activity. The excellent catalytic performance comes from the synergistic effect of ionic liquid cations, halogenated anions, and a large number of oxygen-containing functional groups on the GO surface, a possible reaction mechanism was thus proposed. The study provides a safe, efficient, and industrial-scale continuous reaction system for CO 2 utilization.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Zewei Liang,Jing Wen,Yuanliang Zhou,Tingting Liu,Jinmei Dong,Weixin Zheng,Chenggong Chang,Xueying Xiao,Qiyuan Liu,Xiaogang Zheng
BiOCl 0.5 X 0.5 (X = F, Br, and I) heterojunctions were prepared via the solvothermal approach to achieve the solar-light induced photodegradation of tetracycline hydrochloride (TCH). The photocatalytic activity of BiOCl coupling with BiOI is greatly affected by the molar ratio of Cl/I. The best photocatalytic efficiency of 97.9 % within 120 min is obtained by flower-like BiOCl 0.5 I 0.5 microspheres with a Cl/I molar ratio of 1:1, and the removal efficiency of TCH over BiOCl 0.5 I 0.5 declines to 93.2 % after five cycles. Compared with BiOCl 0.5 Br 0.5 and BiOCl 0.5 F 0.5 , BiOCl 0.5 I 0.5 presents the better photocatalytic activity . Z-scheme junction between BiOCl and BiOI is favorable for the efficient separation and migration of photo-generated charge carriers, and the narrow band-gap structure of BiOCl 0.5 I 0.5 microspheres favors the visible-light harvesting.·O 2 - plays a vital role in BiOCl 0.5 I 0.5 -assisted photocatalytic reaction. However, the change in valance states induced by photo-corrosion is responsible for the solar-light deactivation of BiOCl 0.5 I 0.5 .
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