JOURNAL OF ORGANIC CHEMISTRY
·
2024
·
IF 3.3
Wei-Wei Zhang,Qiang Sha
An efficient B(C6F5)3-catalyzed multicomponent reaction of 2,3-diketoesters, amines, allenes, and nucleophiles was reported, which afforded 2α-functionalized pyrroles in moderate to good yields. The reaction features low catalyst loading, usage of a small amount of solvent, high atom economy, tunable installation of diverse functional groups at 2α-position, and water being formed as the byproduct. This is the first multicomponent reaction that combines vicinal tricarbonyl compounds with allenes.
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高影响因子
Systems Microbiology and Biomanufacturing
·
2023
·
IF 0
Li Xuemei,Zhang Rui,Li Jianjiong,Feng Jinhui,Wu Qiaqing,Zhu Dunming,Ma Yanhe
Cholesterol and phytosterols can be served as the substrates for Actinobacteria to produce the precursors used in the synthesis of steroidal medicines. Cytochrome P450s from CYP125 and CYP142 families initiates the metabolism of cholesterol and/or phytosterols. In this study, we demonstrate the functional redundancy and substrate preference of five cytochrome CYP125s and CYP142s by the unmarked cyp genes deletion strains of Mycobacterium neoaurum NRRL B-3805. CYP125-3 was found to be responsible for the catalytic hydroxylation of both cholesterol and the C24-branched side-chains of phytosterols, while CYP142-2 can only oxidize cholesterol and/or cholest-4-en-3-one. The strain harboring the CYP125-3 produced 6.47 g l − 1 and 5.13 g l − 1 of 4-androstene-3,17-dione (AD) when 15 g l − 1 cholesterol or 17.5 g l − 1 phytosterols used, respectively. While, the strain harboring the CYP142-2 produced 7.10 g l − 1 AD when 15 g l − 1 cholesterol used. The other three cytochrome P450s have a smaller contribution for the degradation of cholesterol and phytosterols. CYP125-3 has the hydroxylation activity on more substrates than that of CYP142-2. This study provided possible guidance to improve the efficiency of AD and other metabolites production from different kinds of sterols by the genetic manipulation.
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NEW JOURNAL OF CHEMISTRY
·
2024
·Vol. 48
·期 46
·19700-19707
·
IF 2.7
Nan Zhou,Fanyi Kong,Ya Tang
The traditional impregnation method for preparing supported catalysts often faces challenges such as particle agglomeration and weak support–metal interactions. This study focuses on utilizing the exsolution method to prepare Fe, Co, and Ni supported catalysts from ABO3-type perovskites, aiming to overcome these challenges. Experimental results show that LaBO3 perovskites with different B site metals (B = Fe, Co, Ni) exhibit different metal exsolution kinetics in the ammonia synthesis reaction. LaNiO3 demonstrates an initial activity of 782.2 μmol g−1 h−1 within the first 2 hours of the reaction, maintaining stability beyond 80 hours. In contrast, LaFeO3 and LaCoO3 exhibit prolonged initiation periods for the metal exsolution process, reaching activities of 7873.8 μmol g−1 h−1 and 8046.7 μmol g−1 h−1, respectively, after approximately 80 hours. The degree of B-site metal exsolution was investigated using X-ray absorption fine structure (XAFS) and Rietveld refinement of XRD data, revealing exsolution rates of 72.03%, 69.3%, and 86.3% for Fe, Co, and Ni, respectively, after 80 hours of reaction. This study not only introduces the exsolution method for ammonia synthesis but also empirically validates several computational predictions, thereby supporting both theoretical and practical research.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2022
·Vol. 169
·期 8
·082503
·
IF 4.386
Xiaolin Ren,Rong Liu,Yuchen Tian,Kaiming Guo,Bin Jiang
Research on cost-effective and high-efficient catalysts for overall water splitting is urgent, and iron group metal borides (IMBs) are a promising candidate. Here, FeCoNiB nanoparticles anchoring on vertically aligned B-doped graphene array (FeCoNiB/BVG) by electroless plating are synthesized for overall water splitting, and FeCoNiB nanoparticles anchoring on other heteroatom-doped graphene substrates (FeCoNiB/XVG, X = N, P, S, O) are prepared for comparison. FeCoNiB/BVG exhibits the best performance with HER and OER overpotential of only 88 mV and 149 mV in 1.0 M KOH, respectively. And FeCoNiB/BVG has a very strong stability for 15 h and the Faraday efficiency of about 94%. The XPS results prove that the best performance of FeCoNiB/BVG is due to the synergistic effect between B in BVG and B in FeCoNiB. This work provides a reference for the rational design of non-noble metal-based electrocatalysts and promotes the application of non-noble metal-based electrocatalysts in the water electrolysis industry.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Yuling Ma,Xiaojing Li,Yun Zhang,Li Chen,Jiangtao Wu,Daojiang Gao,Jian Bi,Guangyin Fan
The release of hydrogen from chemical hydrides is of significant importance for practical applications. In this study, Ru nanoparticles supported on TiO 2 (B) nanotubes , designated as Ru/TiO 2 (B), were synthesized and applied as catalysts for hydrogen evolution from the catalytic hydrolysis of ammonia borane (AB) at 25 °C. Results indicate that Ru/TiO 2 (B) shows high catalytic activity in hydrogen evolution from the hydrolysis of AB with an activation energy of 45.6 kJ mol −1 and a turnover frequency number of 303 mol H 2 ·(mol Ru·min) −1 . The Ru/TiO 2 (B) exhibits a total turnover number of 15,377 in catalytic lifetime measurement in hydrogen generation from the hydrolysis of AB before deactivation. The kinetic studies show that the hydrolysis of AB catalyzed by Ru/TiO 2 (B) is a first-order reaction with respect to Ru concentration, whereas it is a zero-order reaction regarding the AB concentration. The high catalytic activity of Ru/TiO 2 (B) demonstrates that TiO 2 (B) nanotubes are suitable media for nanoparticle immobilization.
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高影响因子
CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Guoqi Ji,Zewen Xiao
Halide double perovskites A2B(I)B(III)X6, where the monovalent B(I) and trivalent B(III) cations adopt a rock-salt-ordered arrangement primarily due to their large charge difference and ionic radius difference, have attracted substantial interest in the field of optoelectronics. On the other hand, the combinations of two divalent B-site cations usually result in AB(II)′0.5B(II)″0.5X3 perovskite solid solutions due to the zero charge difference, rather than the rock-salt-ordered A2B(II)′B(II)″X6 double perovskites. In this work, we report the theoretical design and experimental verification of A2B(II)′B(II)″X6 halide double perovskites with unusually rock-salt-ordered divalent B-site cations. Through theoretical calculations, we demonstrate that introducing divalent transition metal cations with partially filled d orbitals into the double perovskite structure can produce significant Jahn–Teller distortions and thus stabilize the rock-salt-ordered double perovskite structure. Among the considered compounds, Cs2HgCuCl6, Cs2HgPdCl6, and Cs2HgPtCl6 were predicted to be thermodynamically stable. Experimentally, Cs2HgCuCl6 and Cs2HgPdCl6 were successfully synthesized as representative examples of the A2B(II)′B(II)″X6 halide double perovskites. The synthesized pure-phase Cs2HgCuCl6 exhibits a small bandgap of 1.08 eV that is suitable for visible light absorption. Our work provides an approach for designing novel double perovskites with two kinds of divalent cations, which expands the large family of halide double perovskites for optoelectronic applications.
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高影响因子
PEST MANAGEMENT SCIENCE
·
2024
·
IF 3.8
Yuguo Zheng,Mei Chen,Renfeng Zhang,Wei Xue
BACKGROUND Plant pathogens cause substantial crop losses annually, posing a grave threat to global food security. Fungicides have usually been used for their control, but the rapid development of pesticide resistance renders many ineffective, therefore the search for novel and efficient green pesticides to prevent and control plant diseases has become the top priority in crop planting. RESULTS The results of bioassay studies indicated that most of the target compounds showed certain antimicrobial activity in vitro . In particular, compound X7 showed high inhibitory activity against Xanthomonas oryzae pv. oryzae ( Xoo ), with an EC 50 value of 27.47 μg mL −1 , surpassing conventional control agents such as thiazole zinc (41.55 μg mL −1 ) and thiodiazole copper (53.39 μg mL −1 ). Further studies on molecular docking showed that X7 had a strong binding affinity with 2FBW. The morphological change observed by scanning electron microscopy indicated that the surface of Xoo appears wrinkled and cracked under X7 treatment and a total of 2662 proteins were identified by label-free proteomic analysis. Three experiments have elucidated the mechanism whereby X7 induced considerable changes in the physiological and biochemical properties of Xoo , which in turn affected the reproduction and growth of bacteria. CONCLUSION This work represents a pivotal advancement, offering important reference for the research and development therapeutics in combating plant pathogens. © 2024 Society of Chemical Industry.
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PubMed
高影响因子
FOOD CONTROL
·
2022
·
IF 6.652
Xuanyu Sha,Siqingaowa Han,Guoqiang Fang,Nan Li,Dianyang Lin,Wuliji Hasi
In this work, a facile and effective method for assembly and transfer nanoparticles on thin layer chromatography (TLC) plate was proposed and used to combined with layer chromatography-surface-enhanced Raman spectroscopy (TLC-SERS) strategy for detection of Rhodamine B and Sudan I. First, Monodispersed Ag NCs with broadly tunable diameters (from 41 to 67 nm) and 7.25 × 10 5 maximum actual enhancement factor (AEF) were successfully prepared and systematically investigated for its optic performance use in TLC-SERS. Au@Ag NCs were monitored by TEM, SEM and UV–Vis spectrometer. The optical properties of Ag NCs were simulated and the experimental results showed good consistency with simulation results of absorption spectra. Through three phases interfacial technique and a simple transfer method, nanostructures were assembled on the TLC plate. Moreover, the semi-quantitative analysis of Rhodamine B and Sudan I in the range of 1–200 ppm was performed based on the assembled TLC plate with the limit of detection as low as 1 ppm. In addition, the practical feasibility of this strategy was verified by the detection of Sudan I and Rhodamine B in chili oil. In general, this assembled TLC-SERS strategy builds a connection for the application of nanomaterials with rich morphology in TLC-SERS, which has a great application prospect and practical application value.
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高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2022
·Vol. 48
·期 7
·2887-2901
·
IF 3.134
Huang Yan,Xing Wenxin,Zhou Liang,Tian Baozhu,Zhang Jinlong,Zhou Yi
Molybdenum oxide (MoO 3 ), as a transition metal oxide, has excellent catalytic activity, chemical stability, and high application value in the catalytic field. As a typical cocatalyst, noble metals, such as silver and gold, can be decorated with MoO 3 and improve their visible light absorption performance and photogenerated charge separation efficiency to achieve a higher light energy utilization rate. However, the high price of noble metals makes it challenging to realize large-scale industrial applications. Herein, a highly dispersed MoP quantum dot (QDs) decorated MoO 3 nanorods (PMO) was prepared by the co-calcination method to achieve efficient photocatalytic oxidation of target organic contaminants. Rhodamine B (RhB) and norfloxacin (NOR) were used as the model organic contaminants to evaluate the photocatalytic activity of the as-prepared composite photocatalysts. Based on the photoelectric performance and band structure analysis results, the enhancement mechanism of modification with MoP QDs in PMO was proposed. The introduction of MoP QDs in PMO can accelerate electron transfer and achieve a low recombination rate of photogenerated charges. Therefore, the photocatalytic degradation efficiency of RhB and NOR by PMO was higher than that of pristine MoO 3 nanorods and MoP QDs. The degradation efficiency of RhB and NOR could reach more than 97% and 100% within 40 min by PMO-5. Furthermore, photogenerated holes and hydroxyl free radical (·OH) as the primary active oxidants involved in the oxidation process of organic contaminants by PMO-5. PMO-5 still maintained vigorous catalytic activity after five cycles, indicating that it had good chemical stability. This work could provide a new strategy to construct a highly efficient photocatalyst for the efficient degradation of organic contaminants.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 44
·期 2
·537-542
·
IF 3.069
Zhenyu Li,Fa Cao,Lei Wang,Zhiwu Chen,Xiaohong Ji
In this article, novel ternary MoS2/MoO3/TiO2 composite catalysts were developed. The photocatalytic performance of the ternary MoS2/MoO3/TiO2 composites was evaluated by photo-degradation of rhodamine B (RhB). It was found that the photocatalytic ability of the composites was strongly dependent on the mass ratio of MoS2–MoO3 to MoS2–MoO3–TiO2. The ternary composite catalyst with optimum composition showed a fast degradation rate (maximum ∼0.138 min−1), which could degrade over 95% of RhB solution (10 mg L−1) within 20 min under visible light (λ > 420 nm) irradiation. The possible photocatalytic mechanism was proposed based on the trapping photocatalytic experiment and band alignment of the composite. The synergistic effect of the strong absorption of the catalyst and the efficient separation of photogenerated electron–hole pairs by the novel ternary composite contributed to the enhanced photocatalytic activity.
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高影响因子
ChemCatChem
·
2013
·Vol. 5
·期 6
·1517-1523
·
IF 5.181
Yan Liu,Xiaozhao Zhou,Xinmei Pang,Yinying Jin,Xiangju Meng,Xiaoming Zheng,Xionghou Gao,Feng-Shou Xiao
Graphical Join the chain gang: Chain-like ZSM-5 crystals that are synthesized in the presence of starch show higher p -xylene selectivity in m -xylene isomerization than normal, mesoporous, and sheet-like ZSM-5 crystals. ZSM-5 zeolite crystals with controllable b- axis length (sheet-like, S-ZSM-5; chain-like, C-ZSM-5) have been synthesized by using urea and starch as additives in the starting aluminosilicate gels. X-ray diffraction (XRD) patterns and scanning electron microscopy (SEM) images show that these zeolite samples have good crystallinity. Transmission electron microscopy (TEM) images show that there is a strong chemical interaction between the stacked crystals in C-ZSM-5 samples. N 2 sorption isotherms indicate that C-ZSM-5 crystals are mesoporous. Catalytic tests for the formation of p -xylene from m- xylene isomerization show that, compared with other zeolite catalysts, C-ZSM-5 catalysts give both high conversion and improved p -xylene selectivity, which are attributed to the combination of relatively long b -axis length and the present mesoporosity in the crystals. The improvement of p -xylene selectivity in catalytic m- xylene isomerisation is of great importance for selective industrial production of p -xylene in the future.
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高影响因子
Solar RRL
·
2023
·Vol. 7
·期 24
·2300838
·
IF 7.9
Ding Ma,Mengge Li,Bin Yao,Yongfeng Li,Zhanhui Ding,Jiayong Zhang,Chunkai Wang,Yuting Sun,Yue Liu,Xiaofei Sun,Yan Zhu
It is known that high carrier recombination at the p–n junction interface and low carrier separation ability (CSA) are two main problems resulting in low power conversion efficiency (PCE) of the Cu 2 ZnSn(S,Se) 4 (CZTSSe) solar cell. To resolve these problems, one CZTSSe solar cell is prepared through substituting B-doped CdS for CdS in a solar cell with the conventional structure of Ag/ITO/ZnO/CdS/CZTSSe/Mo/SLG and annealing B-doped CdS/CZTSSe/Mo/SLG prior to deposition of ZnO, ITO, and Ag electrode. By optimizing the B doping content in the CdS and annealing temperature and time of the B-doped CdS/CZTSSe, lattice mismatch between CdS and CZTSSe is decreased and width of depletion region is increased, leading to reduction in interfacial recombination, enhancement in CSA and intensity of incident light passing through the B-doped CdS, and so increase in PCE from 7.89% of CZTSSe solar cell using CdS as buffer layer to 10.62%. A mechanism of the increment of the PCE induced by B doping and annealing is suggested. This work proposes a method of increasing PCE of CZTSSe solar cell and advances a deeper understanding of the mechanisms behind various parameters in CZTSSe solar cells through theoretical analysis and calculations.
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高影响因子
危险品化学品经营许可证（带存储）