ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2017
·
IF 6.198
Shenyu Lan,Jinxi Feng,Ya Xiong,Shuanghong Tian,Shengwei Liu,Lingjun Kong
Piezo-catalysis was first used to degrade a nondye pollutant, 4-chlorophenol (4-CP). In this process, hydrothermally synthesized tetragonal BaTiO3 nano/micrometer-sized particles were used as the piezo-catalyst, and the ultrasonic irradiation with low frequency was selected as the vibration energy to cause the deformation of tetragonal BaTiO3. It was found that the piezoelectric potential from the deformation could not only successfully degrade 4-chlorophenol but also effectively dechlorinate it at the same time, and five kinds of dechlorinated intermediates, hydroquinone, benzoquinone, phenol, cyclohexanone, and cyclohexanol, were determined. This is the first sample of piezo-dechlorination. Although various active species, including h+, e–, •H, •OH, •O2–, 1O2, and H2O2, were generated in the piezoelectric process, it was confirmed by ESR, scavenger studies, and LC-MS that the degradation and dechlorination were mainly attributed to •OH radicals. These •OH radicals were chiefly derived from the electron reduction of O2, partly from the hole oxidation of H2O. These results indicated that the piezo-catalysis was an emerging and effective advanced oxidation technology for degradation and dechlorination of organic pollutants.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Caiwen Pan,Xiaoyan Dong,Qinghong Shi,Linling Yu,Yan Sun
Methyl parathion (MP) is a typical organophosphate pesticide widely used in agriculture, causing serious pollution. MP hydrolysis generates a toxic 4-nitrophenol (4-NP) with environmental risks, but a subsequent reduction of 4-NP produces a nontoxic 4-aminophenol (4-AP), which serves as a resource for further use in chemical synthesis. Thus, the detoxification and resourcilization of MP are of great significance for environmental remediation and sustainable development. However, most reports on MP cascade conversion require two different catalysts, each of which is single-catalytic. Herein, we report the first self-cascade nanocatalyst with bicatalytic activities of hydrolysis and reduction based on cupric metal–organic framework (Cu-AZB) nanosheets for the conversion of MP to 4-AP. It was found that Cu-AZB could completely convert MP to 4-AP in the presence of NaBH4 within 10 min. Moreover, hydrolysis was 19-fold accelerated by the NaBH4-mediated reduction in the self-cascade catalysis, so a catalyst with a high cascade conversion efficiency against MP with an activity factor of 513.2 min–1 g–1, a reaction rate constant of 0.25 min–1, and a half-life of 2.82 min was achieved, which was more efficient than literature-reported cascade catalysts. The results demonstrated the application potential of the bicatalytic Cu-AZB in the complete detoxification and conversion of the toxic pollutant into a nontoxic resource through one-pot cascade catalysis.
研究领域:
环境科学
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催化
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材料科学
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化学工程
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2020
·
IF 5.162
Jie Hao,Fangxia Wu,Rong Tang,Yuanyuan Sun,Dehua Liu,Zhenqing Zhang
Oxidized starch (oxStarch) is a major derivative of starch. In present study, 4-acetamide-TEMPO system was firstly applied to prepare specifically oxidized starch, homogeneous 1,4-linked α-D-glucuronan. The impact of oxidant amount, 4-acetamide-TEMPO amount and reaction temperature on the properties of products were investigated. The product structures were characterized with 1 H NMR for degree of oxidation (DO), SEC-MALS for MW, MS for analysis of oxidized oligosaccharides , and in-source fragmented MS for analysis of oxidized polysaccharides . The results showed that the DO of oxStarches increased, but their MWs decreased with the raise of oxidant amount; higher 4-acetamide-TEMPO amount provided higher efficiency of specific oxidation of starch, in which the product has higher DO and MW; no significant difference have been observed between the oxStarches oxidized at 4 and 25 °C, but significant degradation was observed at 50 °C. In each product, having a MW distribution, the portion with smaller size has higher DO. While some unspecific oxidation was still observed observed on the second hydroxyl groups of sugar ring in the following order of priority, position 3 > 2 > 1 > 0.
研究领域:
化学
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材料科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2023
·
IF 3.4
Junjie Li,Wei Feng,Shichun Weng,Zichao Guo,Wanghua Chen
3,4-bis(4-Aminofurazano-3-yl) furoxan (DATF) is a key precursor for the high-energy explosive 3,4-bis(4-nitrofurazano-3-yl) furoxan (DNTF), and it is also a high-nitrogen content energetic material. In this paper, the synthesis process of DATF was characterized using the HPLC technique, and the effects of four reaction parameters have been thoroughly studied. The thermal risk analysis for DATF synthesis was conducted with a reaction calorimeter (RC1) and an accelerating rate calorimeter. It was found that extracting the intermediate 3-amino-4-oxycyanofurazan from the aqueous to organic phases was an important way to improve the yield of DATF. Therefore, hydrophobic ethyl acetate was selected as one reaction solvent. The higher yield of DTAF obtained was about 60%. In addition, HPLC monitoring and reaction calorimetry results indicated that the rate of diazotization and decomposition of diazonium salt was feeding-controlled, and the cycloaddition reaction was a slow process. Most of the reaction heat has been released by the diazotization and decomposition of diazonium salt, while the heat effect of cycloaddition was not significant. Thermal stability analysis supported the conclusion that the decomposition of the reaction mixture was hardly possible to be triggered by the reaction heat. The thermal risk of DATF synthesis was low.
研究领域:
化学工程
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安全科学
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材料科学
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产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
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2020
·Vol. 46
·期 11
·5117-5131
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IF 2.262
Sun Li,Zhou Mingliang,Yin Zheng,Zhang Lixin,Dou Binlin,Su Wenxian
Abstract A green, rapid and controllable synthesis of gold nanoparticles (Au NPs) was achieved using the mulberry fruit (MF) extract as reducing and capping agent at room temperature. Obtained Au NPs were characterized by ultraviolet–visible spectrum, transmission electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, selected area electron diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy analyses. It could be found that Au NPs had a small size of 4.2–20.1 nm, face-centered cubic crystalline structure and homogeneous dispersion, indicating strong reducing and capping capacities of the MF extract. Meanwhile, the morphology (quasi-sphere/sphere) of Au NPs could be controlled only by adjusting the MF extract concentration. Furthermore, based on the 4-nitrophenol (4-NP) reduction reaction, as-prepared Au NPs exhibited excellent photocatalytic activity and stability in 30 days. Under sunlight irradiation, 4-NP could be completely reduced in 4 min and its rate constant could reach up to 0.91 min −1 . And the rate constant could be linearly adjusted by the MF extract concentration or the amount of Au NPs hydrosol. In addition, it could also be found that the light source with short wavelength could obviously elevate the photocatalytic activity of Au NPs, attributed to the hot-electron effect. Clearly, as-obtained Au NPs can have great potential applications in wastewater treatment. Graphic abstract
研究领域:
材料科学
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环境科学
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纳米技术
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产品关联
DOI
高影响因子
POLYMER
·
2018
·
IF 3.483
Yongjian Lou,Zhongxiang Zhao,Zhiwei Chen,Zenghui Dai,Feiya Fu,Yanyan Zhang,Lei Zhang,Xiangdong Liu
High melting temperature and viscosity of most benzoxazine monomers are challenging problems in processing, especially for preparation of composites. The present work introduces the “reactive diluent” concept to improve the processability of benzoxazines. A benzoxazine monomer having a vinyl group is first synthesized from 4-vinylguaiacol (4VG), and then dissolved in a reactive diluent, styrene or methyl methacrylate . The resulting solutions show low viscosity (less than 2 mPa s), and exhibit high reactivity during free radical and ring-opening polymerizations, successively. Furthermore, the solutions are applied to fabricate cotton fabrics reinforced composites. Both of them possess high glass transition temperature and excellent mechanical properties , which have potential applications as structural components.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
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2016
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IF 1.045
Xiaodong Ji,Jingling Yan,Xiuju Liu,Zikun Wang,Zhen Wang
Several partially bio-based polyimides have been successfully synthesized by polycondensation between bis(4-aminophenyl)isohexides with various commercial dianhydrides. Flexible and free-standing films were readily obtained from their poly(amic acid) or polyimide solutions. A systematic investigation of the structure–property relationship of polyimides highlights the significant impact of the isohexides moieties on their physical and mechanical properties (glass transition temperature, inherent viscosity, thermal stability, solubility, and mechanical properties). The results revealed that these polyimides exhibited comparable thermal stability and mechanical properties to those of petrochemical-based ones.
研究领域:
材料科学
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有机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2022
·
IF 4.198
Jiateng Wang,Yunqing Zhuang,Bingxue Yu,Xiaofeng Wang,Gehua Bi,Xin Huang,Weimin Zhang
A general and efficient method for the synthesis of 4-sulfenylated oxazoles is described. Trisubstituted oxazoles are obtained in good to excellent yields from β-keto sulfoxides and nitriles. The mechanistic study suggests that the reaction proceeds via the nucleophilic addition of nitriles to the in situ formed α-carbonyl cation followed by intramolecular cyclization.
研究领域:
有机化学
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药物化学
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DOI
高影响因子
VACUUM
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2023
·
IF 4
Pengfei Zhu,Hua Fang,Yanli Zhu,Jinqiang Zhou,Xueyong Guo
Ammonium perchlorate-based molecular perovskites (DAP-4) have garnered immense interest due to their exceptional burst performance and good thermal stability. Similarly, metallic hydrides are widely acknowledged as an exceedingly promising material class for implementation in energetic systems, given their exceptional hydrogen storage density. Therefore, it is crucial to investigate the impact of hydrogen storage material MgH 2 on the thermal decomposition and combustion characteristics of molecular perovskite materials ((H 2 dabco)[NH 4 (ClO 4 ) 3 ],DAP-4). In this study, DAP-4/MgH 2 composites were synthesized and characterized for their morphology, structure, elemental distribution, thermal decomposition properties, and combustion properties. The findings indicated that the inclusion of MgH 2 reduce the thermal decomposition temperature of DAP-4. Moreover, when MgH 2 was added at a mass ratio of 5 wt %, the apparent activation energy ( E a ) decreased to 212.0 kJ/mol, while the peak combustion pressure and boosting rate increased with more intense flames. A plausible thermal decomposition and combustion mechanism of DAP-4/MgH 2 composites was postulated. This study enhances our understanding of the thermal decomposition and combustion properties of DAP-4 and magnesium hydride in energy-containing systems.
研究领域:
材料科学
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能量材料
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热化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENT INTERNATIONAL
·
2020
·
IF 7.577
Song Li,Jingchun Tang,Qinglong Liu,Xiaomei Liu,Bin Gao
Nano zero-valent iron (nZVI) and its composite materials have been extensively studied in the field of environmental remediation. However, the oxidation and agglomeration of nZVI limits the large-scale application of nZVI in environmental remediation. This study developed a two-step method to prepare stable carbon-coated nZVI (Fe 0 @C) which combined hydrothermal carbonization and carbothermal reduction methods and used glucose and iron oxide (Fe 3 O 4 ) as precursors. When the carbothermal reduction temperature was 700 °C and the elemental molar ratio of carbon to iron was 22:1, stable Fe 0 @C can be generated. The nZVI particles are encapsulated by mesoporous carbon and embedded in the carbon spheres. The unique structure of carbon coating not only inhibits the agglomeration of nZVI, but also makes nZVI stable in air for more than 120 days. Not only that, the as-synthesized Fe 0 @C exhibited high catalytic activity toward the degradation of 4-chlorophenol (4-CP) by activating persulfate. Different from conventional nZVI catalysts in generation of sulfate radicals, Fe 0 @C selectively induced hydroxyl radicals for 4-CP degradation. Moreover, Fe 0 @C has been shown to efficiently degrade 4-CP by using the dissolved oxygen in water to form hydroxyl radicals. This study not only provides a simple, green method for the preparation of stabilized nZVI, but also provides the possibility of large-scale application of nZVI in the field of environmental remediation.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
CLAYS AND CLAY MINERALS
·
2024
·Vol. 71
·期 6
·745-759
·
IF 2
Peiping Zhang,Tongtong Liu,Xue Sun,Qing Liang,Wei Zhang,Weikun Ning,Wenqing Li,Xuefa Shi,Shiding Miao
Natural clays are often employed as substrates for heterogeneous catalysts. However, the direct use of raw clays as catalysts has received less research attention. The objective of the present study was to help fill this gap by investigating catalytic properties of raw pelagic clays (PC) collected from the Indian Ocean. The raw PC were discovered to be efficient catalysts in the reduction of 4-nitrophenol (4-NP) in the presence of NaBH4. The effects of parameters including pH values, dosages of PC, and initial concentration of 4-NP and NaBH4 on the conversion or degradation rate of 4-NP have been investigated. The 4-NP was observed to be completely degraded within 480 s under conditions of 0.10 mM 4-NP, 25.0 mM NaBH4, and 0.20 g/L PC at an initial pH value of 7.0. The apparent rate constant was evaluated to be 27.53 × 10–3 s–1. Unlike previous pseudo-first order kinetics experiments, the induction period and degradation stages were observed to occur simultaneously during the PC catalysis. The S-shaped kinetics for 4-NP conversion was found to be perfectly matched by Fermi's function, and the enzyme-like catalysis by PC was appointed to describe the kinetics. Species of Fe(III), Mn(IV), and Mn(III) in PC were found to be essential, and were partly reduced to Fe(0) and Mn(II) by NaBH4 in our reaction, contributing to rapid conversion of 4-NP to 4-aminophenol (4-AP). The raw PC was converted to magnetic PC (m-PC) particles, which made PC particles separate easily for cycling use. This discovery would also have applications in continuous flow-fluid catalysis.
研究领域:
环境科学
·
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CONTROL
·
2023
·
IF 6
Yanhua Xu,Huiyan Dong,Chenxi Liu,Haiwei Lou,Renyong Zhao
Aflatoxin B 1 (AFB 1 ) is the most common mycotoxin with the highest toxicity, posing a threat for food contamination. In this study, the bacterium Pseudomonas aeruginosa M-4 was isolated from rotten wood, and its culture supernatant showed a 56.79% AFB 1 degradation rate. Treatment with proteinase K, sodium dodecyl sulfate, and trichloroacetic acid decreased the AFB 1 degradation rate in the culture supernatant to 20.71%, 10.83%, and 19.62%, respectively. Moreover, heating the culture supernatant at 121 °C for 30 min increased in the AFB 1 degradation rate to 84.76%, indicating effective degradation by heat-resistant and inducible extracellular proteins or enzymes. P. aeruginosa M-4 reduced the content of AFB 1 in contaminated maize (90.57%, 14 d). Additionally, high-performance liquid chromatography and ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry analyses showed that AFB 1 was biotransformed into structurally different compounds, (C 17 H 16 O 6 ), (C 16 H 14 O 5 ), (C 17 H 14 O 5 ), and (C 16 H 10 O 6 ). According to the structure-activity relationship, these degradation products were produced by the destruction of partial toxic sites of AFB 1 , so the toxicity of these products may be lower than that of AFB 1 . Thus, P . aeruginosa M-4 has excellent potential for application in the detoxification of AFB 1 in food and feed.
研究领域:
食品科学
·
微生物学
·
毒理学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）