International Journal of Polymer Science
·
2019
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IF 1.892
Weiping Du,Guiming Zhang,Song Wang,Lianjiang Tan,Huifang Chen
An optical polythiourethane based on m-xylylene diisocyanate (XDI) and 4-mercaptomethyl-3,6-dithia-1,8-octanedithiol (BES) has been studied. Triethylamine was adopted as a catalyst, and the solid-state isothermal cure reaction was carried out using FTIR spectroscopy, in the temperature range of 75°C-105°C. The -NCO absorption band of XDI was used to monitor the conversion of diisocyanate into polythiourethane. The reaction rate enhanced with an increase in the content of the catalyst, and the gel time determined by swelling test was shorter for the system with higher catalyst content. Kinetic parameters were calculated from the infrared spectrum data, and the results showed that the curing reaction of polythiourethane accords with first-order kinetic characteristics. The activation parameters obtained from the evaluation of kinetic data were , , and . The observed negative entropy of activation value supported the formation of a transition state in the cure reaction.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
ACS Omega
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2022
·
IF 4.132
Danting Xu,Xia Zhu,Jiakun An,Gaoyu Chen,Jianchun Bao,Xiangxing Xu
As a narrow band semiconductor at room temperature and a metallic material above ∼68 °C, functional VO2 films are widely investigated for smart windows, whereas their potential for ultraviolet–visible–infrared (UV–vis–IR) broad spectral photodetectors has not been efficiently studied. In this report, photodetectors based on VO2–ZnO nanocrystal composite films were prepared by nanocrystal-mist (NC-mist) deposition. An enhanced photodetection switching ratio was achieved covering the ultraviolet to infrared wavelength. Due to the synergetic effect of nanosize, surface, phase transition, percolation threshold, and the band structure of the heterojunction, the transfer and transport of photogenerated carriers modulate the device performance. This study probes new chances of applying VO2-semiconductor-based nanocomposites for broad spectral photodetectors.
研究领域:
材料科学
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光电子学
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纳米技术
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DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2017
·Vol. 147
·期 7
·1802-1810
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IF 2.799
Hong Runrun,He Yufei,Miao Chenglin,Feng Junting,Li Dianqing
Abstract Pd–Ir mesocrystals with rough surface and highly branched structure were synthesized through a facile co-reduction method. The morphology evolution shows the mesocrystals were formed by oriented attachment of nanoparticles, and abundant defects sites as well as synergetic effect between building units were formed during mesocrystals oriented attachment process. Therefore, the supported Pd–Ir mesocrystals show a significant enhancement in catalytic performance in hydrogenation of 2-ethylanthraquinone compared with conventional Pd–Ir nanoparticles. The high activity can be ascribed to high densities of defect sites in Pd–Ir MCs catalyst, which facilitated H 2 activation. In addition, the geometric effect of Pd–Ir MCs catalyst was responsible for inhibiting further hydrogenation of eAQH 2 to undesired consecutive byproducts. Graphical Abstract
研究领域:
催化化学
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材料科学
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高影响因子
Asia-Pacific Journal of Chemical Engineering
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2022
·Vol. 18
·期 1
·e2840
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IF 1.777
Qiaolin Ren,Ruirui Yang,Junying Li,Wenjun Yan,Zhongde Wang,Ailian Wu
Electrocatalytic oxidation technology has been proved as an efficient method for degradation in organic wastewater. The service lifetime and degradation efficiency of the electrode, one crucial struggle, limits the broad application of electrocatalytic oxidation technology. Herein, a Ru/Ir doped TiO 2 electrode with a long service lifetime was developed. Accelerated life experiment showed that the service life of an electrode was 33 h when the concentration of sulfuric acid was 1 M and the current density was 2000 mA·cm −2 . The influence on the phenol degradation was evaluated by researching the operating parameters. In particular, the possible mechanism of phenol removal at different pH is elucidated. It is found that acidic environment is favorable for chemical oxygen demand (COD) and phenol removal at a current density of 20 mA·cm −2 , pH 3 at 800 ppm NaCl, which can make the removal rates of phenol and COD with Ru/Ir doped TiO 2 anode up to 97.21% and 100%. In addition, it was demonstrated that the hydroxyl radicals play a foremost role in the degradation of phenol. Given the well stability and high service life, the Ru/Ir doped TiO 2 electrode holds promise for further industrial application in wastewater treatment.
研究领域:
环境科学
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电化学工程
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2026
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IF 9.7
Shiyao Lu,Shuning Li,Yancheng Wu,Lin Cheng,Huanyu Li,Miao Wang,Meisheng Liang,Qiaoyan Li
Simultaneous elimination of CO and NO x remains a formidable challenge, largely due to the competitive oxidation reactions present in industrial emission streams. Although much prior research has concentrated on enhancing performance at low temperatures, limited catalytic activity in O 2 -containing environments has recently gained attention as a pressing issue. Herein, we developed an Ir/Si 2 Ce 1 O x catalyst via a SiO 2 -induced structural regulation strategy, which promotes the fine dispersion of CeO 2 and enables the strong anchoring of Ir species. This rational design facilitates the preferential exposure of the active Ir 0 (111) crystal plane, a key factor associated with optimized surface adsorption behavior. Furthermore, the abundant Ir-O-Ce interfaces in this unique architecture induce significant electron transfer from Ce to Ir, thereby stabilizing the metallic Ir 0 . Concurrently, the activated lattice oxygen at the Ir-O-Ce interfaces facilitates the formation of the key nitrate intermediates. Consequently, the catalyst demonstrates outstanding NO reduction and CO oxidation efficiency at 250 °C under oxygen-containing conditions. Our findings highlight a viable approach for stabilizing Ir 0 through tailored Ir Ce interactions, offering a pathway to robust CO-selective catalytic reduction (CO-SCR) performance in an oxidative environment.
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PubMed
高影响因子
HIGH PERFORMANCE POLYMERS
·
2023
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IF 2.1
Junjie Zhou,Kangkang Guo,Fan Wang,Yaping Zhu,Huimin Qi
Herein, the catalytic effects of aromatic amines with different structures on the room temperature curing of bisphenol E cyanate (BECy) have been studied using differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. Our results revealed that the mixed amine comprised of aniline and N,N-dimethyl-p-phenylenediamine (AN/NNDPA) bearing primary amino groups in its structure was a highly effective catalyst for the room temperature curing of cyanate esters. When the cyanate ester and mixed amine were combined at a molar ratio of 100:5 and cured at room temperature for 5 days, the curing degree of BECy resin reached 79.7%. The room temperature curing mechanism of the BECy-AN/NNDPA system was investigated using pyrolysis gas chromatography-mass spectrometry (PY GC-MS). Our results showed that the formation reactions of the intermediate structure and cyclotrimerization reactions occurred during the room-temperature curing process. The activation energies of BECy and different aromatic amine systems at different heating rates were determined using non-isothermal DSC. The results further demonstrated the catalytic effect of AN/NNDPA on the cyanate ester curing reaction. BECy-AN/NNDPA cured at room temperature has suitable heat resistance and a 5% weight loss temperature (Td5) of 361°C.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Kangwang Wang,Longfu Li,Peifeng Yu,Nannan Tang,Lingyong Zeng,Kuan Li,Chao Zhang,Rui Chen,Zaichen Xiang,Huichao Wang,Yongqing Cai,Kai Yan,Huixia Luo
Topological semimetals with protected surface states mark a new paradigm of research beyond the early landmarks of band-structure engineering, allowing fabrication of efficient catalyst to harness the rich metallic surface states to activate specific chemical processes. Herein, we demonstrate a facile solid-phase method for in-situ doping of Ir at the Os sites in the Os 3 Sn 7 , an alloy with topological states, which significantly improves the photocatalytic performance for the reduction of CO 2 to CO and CH 4 . Experimental evidence combined with theoretical calculations reveal that the nontrivial topological surface states greatly accelerate charge-separation/electron-enrichment and adsorption/activation of CO 2 molecules, rendering highly efficient reaction channels to stimulate the formation of *COOH and *CO, as well CHO*. This work shows the promise of achieving high photocatalytic performances with synthesizing topological catalysts and provides hints on the design of novel topological catalysts with superior photoactivity towards the CO 2 reduction reaction.
研究领域:
材料科学
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催化化学
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环境科学
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DOI
高影响因子
COMPOSITES PART B-ENGINEERING
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2021
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IF 9.078
Hafezeh Nabipour,Xin Wang,Lei Song,Yuan Hu
Organic-inorganic hybrid flame retardant technology integrates independent ingredients into a whole, thus showing advantage of simultaneous improvement in flame retardant, smoke suppressant and mechanical properties of polymers over traditional flame retardants. In this work, a novel organic-inorganic hybrid flame retardant denoted as IR-MOF-3-Mel was synthesized by covalent hybridization of isoreticular metal-organic framework-3 (IR-MOF-3) with melamine. A relatively low amount of IR-MOF-3-Mel nanoparticles dramatically decreased the fire risk of epoxy resin (EP). Specifically, the EP with only 2.0 wt% of IR-MOF-3-Mel achieved a limiting oxygen index (LOI) of 30.5% as well as a UL-94 V-0 classification, whereas its counterpart with 2.0 wt% of IR-MOF-3 showed a LOI of 25.0% and no classification in UL-94 test. Furthermore, the peak heat release rate , total heat release and smoke production rate of the EP with 2.0 wt% of IR-MOF-3-Mel was declined by 74.0%, 71.4% and 35.6%, respectively, compared to neat EP. Additionally, the glass transition temperature , the tensile strength , and the young's modulus were 11 °C, 38%, and 27% higher than those of neat EP, respectively. The flame retardant mechanism analysis clarified that IR-MOF-3-Mel contributed to formation of a char layer with a high level of thermal resistance and graphitization which accounted for significantly reduced fire risks.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Frontiers in Endocrinology
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2022
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IF 6.055
Liu Shuowen,Zhang Yao,Yang Fang,Gu Jingna,Zhang Ruyue,Kuang Yingying,Mai Wantong,Zheng Chengbo,Yu Yang,Lu Ruling,Zeng Lei,Cao Hongying,Long Yongling
This study explored the possible connection between the insulin resistance-targeting protein adipokine lipocalin-2 (LCN-2) and NF-κB signaling pathway in the inflammatory microenvironment in PCOS-IR model rats to determine the pharmacological mechanism of modified Cangfu Daotan decoction (MCDD) intervention for PCOS-IR. We used a high-fat diet (42 days) combined with letrozole (1 mg/kg/day, 42 days) to establish a PCOS-IR rat model. From the third week after modeling, the rats were given continuous administration of MCDD (high dose with 31.68 g/kg, medium dose with 15.84 g/kg, and low dose with 7.92 g/kg) for 28 days. Serum, ovarian tissue, liver, and adipose tissue were collected after the last gavage. Enzyme-linked immunosorbent assay, hematoxylin-eosin (HE) staining, Masson staining, qRT-PCR, and Western blot experiments were performed to detect various indicators. Our results showed that MCDD could reduce body weight and abdominal fat weight; restore normal estrous cycle and ovarian function; alleviate fatty liver; regulate HOMA-IR and OGTT index; reduce serum inflammatory factor levels, LCN-2 level, and gene expression; and regulate the insulin signal transduction and NF-κB pathways in PCOS-IR rats. Thus, MCDD may play a role in improving ovarian function in PCOS-IR rats by downregulating NF-κB/LCN-2 proteins and upregulating the gene expression of Insr/Irs-1/Glut4 in the insulin signaling pathway in the inflammatory environment.
研究领域:
药理学
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内分泌学
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妇科学
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分子生物学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Defu Yin,Zewei Hu,Mingya Liu,Jingyun Zhang,Hanli Zheng,Yunxi Hou,Shitao Yu,Lu Li,Shiwei Liu,Yue Liu
The highly stereoselective hydrogenation of α-pinene was very important and challenging in the utilization of natural products at mild conditions. Here, we reported a core–shell catalyst coated with Ir metal particles by mesoporous silica shell, and revealing the dependence of reducing agents during the preparation process. The prepared nano catalyst exhibited excellent performance in the hydrogenation of chiral substance α-pinene, especially under very mild conditions (40 °C, 1 MPa H 2 and 2 h), with a yield of cis -pinane reaching ∼99 %. The characterization methods revealed that the excellent performance was attributed to the strong hydrogenolysis ability of Ir particles. DFT results further indicated that α-pinene can stably adsorb on the edge sites of Ir metal in a cis structure, thereby achieving highly stereoselective hydrogenation. This work utilized heterogeneous catalysis to achieve performance close to that of homogeneous catalysts. The stable core shell structure greatly prolonged the lifespan of the catalyst and overcame the drawbacks of homogeneous catalysts. This work provided more reference cases for chiral hydrogenation.
研究领域:
催化
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材料科学
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化学工程
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有机化学
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DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2024
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IF 15.7
Zhaoping Shi,Ziang Wang,Hongxiang Wu,Meiling Xiao,Changpeng Liu,Wei Xing
The development of high-performance oxygen evolution reaction catalysts with low iridium content is the key to the scale-up of proton exchange membrane water electrolyzer (PEMWE) for green hydrogen production. Single-site electrocatalysts with maximized atomic efficiency are held as promising candidates but still suffer from inadequate activity and stability in practical electrolyzer due to the low site density. Here, we proposed a NaNO 3 -assistant thermal decomposition strategy for the preparation of high-density Ir single sites on MnO 2 substrate (NaNO 3 -H-Ir-MnO 2 ). Direct spectroscopic evidence suggests the inclusion of NaNO 3 accelerates the transformation of Ir-Cl to Ir-O coordination, thus generating uniform dispersed high-density Ir single sites in the products. The optimized H-Ir-MnO 2 demonstrates not only high intrinsic activity in a three-electrode set-up but also boosted performance in scalable PEMWE, requiring a cell voltage of only 1.74 V to attain a high current density of 2 A cm ‒2 at a low Ir loading of 0.18 mg Ir cm ‒2 . This work offers a new insight for enhancing the industrial practicality of Ir-based single site catalysts.
研究领域:
材料科学
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电化学
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2024
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IF 20.2
Dongze Li,Wei Tu,Yuxiang Jin,Chao Wang,Song Jin,Wei Liu,Erhong Song,Zhangquan Peng,Junyuan Xu,Ligang Feng
Understanding the intricate mechanisms from material fabrication to catalytic reaction is crucial in energy chemistry. Herein, we elucidate the underlying mechanisms from catalyst to catalysis on Ir-segregated SrIrO 3 (Ir/SrIrO 3 ) as an efficient hydrogen evolution reaction (HER) catalyst in acidic conditions. During the phosphorization-assisted reduction process, in-situ spectroscopic analysis revealed that hydrogen radicals (H·) from the dissociation of P-H bonds attack the lattice oxygen at edge Ir-O sites, resulting in the segregation of Ir atoms and the formation of robust Ir-O interfacial structures between exsolved Ir clusters and the oxygen sites in SrIrO 3 . These interfacial structures are essential for the high performance of HER, while SrIrO 3 provides structural stability. The protons in the electrolyte are activated at the Ir nanocluster sites, incorporating oxygen in SrIrO 3 through the Ir-O interface, forming a reconstructed Ir-OH structure. This structure maintains both thermodynamic and electrochemical stability by adjusting hydrogen diffusion, embedding, and surface hydrogen coverage to sustain dynamic equilibrium during the catalytic process. Theoretical analysis confirms the necessity of the stable Ir-O interface via Ir- 5d and O- 2p orbital hybridization and hydrogen intercalation, optimizing charge redistribution, hydrogen bond length, and hydrogen adsorption free energy for enhanced HER kinetics. This study provides new insights into catalyst development by elucidating the relationship between catalyst structure and catalytic performance.
研究领域:
能源化学
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催化材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）