BIOCHEMICAL ENGINEERING JOURNAL
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2017
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IF 2.892
Juan Han,Li Wang,Yun Wang,Jian Dong,Xu Tang,Liang Ni,Lei Wang
A geometrically symmetric four – arm dendritic polymer 4-arm-PEG-NH 2 was employed to modify on the surface of Fe 3 O 4 as support for cellulase immobilization. Glutaraldehyde was used as a coupling agent of this magnetic support to covalently immobilize cellulase. The morphology and properties of the synthesized magnetic material were characterized by Fourier transform infrared (FT-IR) spectroscopy, vibrating-sample magnetometer (VSM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The properties of immobilized enzyme such as the optimum temperature and pH, Michaelis constant, thermal stability, reusability and storage stability were investigated. The loading capacity of cellulase was 132 mg/g. Compared with free cellulase, immobilized cellulase showed wider pH and temperature ranges, higher operational stability and good storage stability. Besides, the results of hydrolysis filter paper and microcrystalline cellulose showed that the catalytic effect of immobilized cellulase on the free cellulase was increased by about 76%.
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高影响因子
MOLECULES
·
2025
·Vol. 30
·期 6
·1396
·
IF 4.6
Xiangwen Lv,Anruo Luo,Xiong Tong,Jianhua Chen,Sheng Jian
Chalcopyrite and molybdenite are vital strategic metal resources. Due to their close association in ores, flotation methods are commonly used for separation. The flotation separation method primarily employs the “copper depression and molybdenum flotation” process, enhancing the wettability difference between chalcopyrite and molybdenite through a chalcopyrite depressant. Traditional depressants often face challenges, including low selectivity, high dosage requirements, poor stability, and significant environmental pollution, highlighting the need for new, highly selective green reagents. This study introduces the novel chalcopyrite depressant 2-mercapto-6-methylpyrimidin-4-ol (MMO) for flotation separation. The influence of MMO on chalcopyrite and molybdenite flotation recovery was examined through microflotation experiments. Additionally, the effects of MMO and ethyl xanthate on surface wettability were assessed via contact angle measurements. The adsorption microstructure and interaction mechanism of MMO on chalcopyrite were elucidated using FT-IR, TOF-SIMS, and XPS analyses and DFT simulations. Results indicate that MMO enhances chalcopyrite hydrophilicity and exhibits a strong depressing effect on its flotation, while minimally impacting molybdenite recovery. Thus, it serves as an effective depressant. During adsorption, N and S atoms in MMO donate electrons to Fe and Cu ions, leading to triple bond adsorption and a stable chelate structure. These findings are crucial for achieving a greener and more efficient flotation separation of copper and molybdenum.
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高影响因子
GREEN CHEMISTRY
·
2024
·
IF 9.3
Jie Li,Pengpeng Shao,Weijie Geng,Peng Lei,Jing Dong,Yingnan Chi,Changwen Hu
The oxidative depolymerization of β-O-4 linkages into value-added aromatic chemicals is of great importance for lignin valorization. However, achieving highly selective and rapid cleavage of β-O-4 linkages under mild conditions remains a challenge. Herein, cobalt–cobalt oxides (Co-CoOx) supported on N-doped carbon (CoMA/C900) combined with a green and recyclable base K7HNb6O19 (KNb6) have shown remarkable activity for the one-step oxidative cleavage of lignin β-O-4 linkages. Under relatively mild conditions (100 °C, 0.2 MPa O2), a lignin β-O-4 alcohol model compound was almost completely converted within 3 h, affording a narrow product distribution of phenol (yield: 99%) and methyl benzoate (yield: 98%). Based on the control experiments, kinetic study, and spectroscopic analysis, a synergistic oxidative cleavage mechanism was proposed: CoMA/C900 activates molecular oxygen to form a superoxide radical, while basic KNb6 promotes deprotonation of secondary alcohol, and they synergistically catalyze the oxidation of β-O-4 alcohol and the rapid cleavage of Cβ–O and Cα–Cβ bonds. During the reaction, the oxidation of β-O-4 alcohol to β-O-4 ketone is the rate-determining step, while the cleavage of PP-one to phenol and methyl benzoate can be completed within 15 min. Moreover, the CoMA/C900–KNb6 catalyst is recyclable at least three times and highly active for the oxidative cleavages of other lignin models and organosolv birch lignin.
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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2025
·
IF 3.2
Yao Shuaikang,Zhao Jingkun,Shao Guolin,Gao Siyu,Zhai Shangru,Xiao Zuoyi,Zhang Feng
The development of a catalyst with high catalytic activity and selectivity remains a crucial challenge in the field of heterogeneous catalysis. In this work, we demonstrated a versatile procedure for the immobilization of ultrafine and monodispersed metal nanoparticles onto glutaraldehyde-crosslinked polyethyleneimine-modified calcium alginate (GLA-PEI/Ca-SA) beads. The resulting hydrogel beads underwent comprehensive characterization through scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The results revealed that well-dispersed Ag, Cu, and Ni nanoparticles, with a mean size of 3.5, 2.6, and 4.1 nm, respectively, were successfully loaded onto the surface of GLA-PEI/Ca-SA beads with porous fiber network structure. Notably, the Ag/GLA-PEI/Ca-SA exhibited outstanding catalytic activity and stability, achieving over 95% conversion within 7 successive cycles towards the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH 4 in aqueous solution. Particularly, the Cu/GLA-PEI/Ca-SA beads displayed the highest catalytic activity for the reduction of 4-NP with a kinetic reaction rate constant of 1.56 × 10 −2 s −1 . We expect that this work will provide a novel and effective strategy to design highly efficient catalysts across various catalytic reactions. Graphical Ultrafine and monodispersed Ag nanoparticles within 5 nm on GLA-PEI/Ca-SA beads with high catalytic activity for rapid 4-NP reduction.
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ENERGY
·
2024
·
IF 9
Bingshuo Li,Aorong Ding,Tianhua Yang,Zhuo Wang,Haijun Zhang,Xingping Kai,Rundong Li
Hydrodeoxygenation (HDO) of phenols has significant potential for the synthesis of cycloalkane. In this study, a Ni-based magnetic molecular sieve catalyst, Ni/HZSM-5@SiO 2 @Fe 3 O 4 , was carefully prepared and systematically characterized using various analytical methods. A screening of the HDO reaction conditions was carried out using a typical phenolic compound of 4-ethylphenol. Under the optimal reaction conditions (240 °C, 3 h) with n-dodecane as the solvent, the 6 % Ni/HZSM-5@SiO 2 @Fe 3 O 4 catalyst showed excellent performance, achieving a 4-ethylphenol conversion of 59.3 % and an ethylcyclohexane selectivity of 85.1 %. In comparison to conventional Ni/HZSM-5, the magnetic micromesoporous molecular sieve catalyst exhibited superior catalytic activity, alkane selectivity and recyclability, with a catalyst recovery ratio of 95 %. Furthermore, the effect of liquid-solid mass transfer efficiency on the ethylcyclohexane selectivity considering of the stirring speed was studied, and the selectivity was increased from 81.6 to 85.1 % when the speed was increased from 400 to 600 rpm. This finding was further substantiated by Fluent numerical simulation. To elucidate the HDO pathway of 4-ethylphenol on Ni/HZSM-5@SiO 2 @Fe 3 O 4 , a comprehensive reaction pathway was proposed, providing insights into the catalytic mechanism.
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ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Tianhang Liu,Kaisheng Yao,Hang Li,Qi Wang,Tianhang Han,Aozhou Wang,Haili Zhao,Weiwei Lu
Developing a simple, environmentally friendly, and mild method to one-step prepare bimetallic nanoframes is pretty important but still technically challenging. In this paper, a simple and easy-to-operate ionic liquid (IL)-regulated protocol is proposed to fabricate Au–Pd superbranched trigonal nanoframes (STNFs) in water at room temperature. In the aqueous solution containing precursors (Na2PdCl4 and HAuCl4) and a reducing agent (ascorbic acid), a common IL 1-octyl-3-methylimidazolium chloride ([C8mim]Cl) was used to guide the anisotropic growth and construction of Au–Pd STNFs, brightly showing green and energy-saving characteristics. Au–Pd STNFs take shape as unique two-dimensional (2D) trigonal frameworks containing multilevel orderly branches. It is found that [C8mim]Cl is crucial to the formation of Au–Pd STNFs. Owing to the unique structures, high specific surface areas, large freestanding sizes, and probably electronic effects between Au and Pd, Au–Pd STNFs-1 exhibit dramatically enhanced catalytic activity, selectivity, durability, and convenience for recycling in the 4-nitrostyrene hydrogenation reaction. Specifically, 4-nitrostyrene can be converted completely only within 5.0 min at 25 °C under atmospheric pressure, and the selectivity toward 4-nitroethylbenzene is as high as 100% and maintains good performance after five cycles. It is expected that well-constructed Au–Pd STNFs also display advanced potential in other applications.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
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IF 5.8
Qingshan Dai,Jiarui Huang,Xia Qiu,Nannan Wang,Dongmei Wang,Yongxin Li
Investigating the kinetics and mechanisms of catalytic hydrogenation reaction is important for fundamental research and chemical engineering, especially at single nanowire/nanoparticle level. In this work, we constructed a dual-functional single Pt@Au nanowire (Pt@Au NW) reaction platform, which was used for in-situ monitoring the p-nitrothiophenol (4-NTP) catalytic reduction process by using surface-enhanced Raman scattering (SERS) and UV–vis spectroscopy. The conversion of reactants and intermediates as well as the product generation during the reaction process were analyzed carefully, and the influencing factors of temperature and light were also discussed. Moreover, the density functional theory (DFT) was used to further investigate the effect of the single Pt@Au NW on catalytic hydrogenation reaction of 4-NTP. The results show that the single Pt@Au NW can be a good platform for in-situ monitoring catalytic hydrogenation reaction of 4-NTP with excellent catalytic activity, high stability, and good reproducibility, and clarified that trans -dimercaptoazobenzene ( trans -DMAB) intermediates were produced that are further converted to the p-aminothiophenol (4-ATP). The work will not only give researchers new insights into the combination of the single nanowire/nanoparticle with spectroscopic techniques, but may also inspire further in-depth studies of multifunctional catalysts for catalytic hydrogenation reaction at single entity level.
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ACS Applied Polymer Materials
·
2024
·
IF 4.4
Mengyao He,Rui Liu,Xiaoli Li,Gan Zhang,Guanxing Lao,Song Guo,Yuanli Liu
Compared with traditional luminescent materials, nonconventional luminogens have been extensively studied due to their unique properties and wide range of applications. However, the study of nonconventional luminescent polymers is rare because most luminescent polymeric materials can only emit light at high concentrations and require noble metal catalysts for synthesis. Particularly, their application in the field of metal ion detection and biological imaging is still restricted. To expand its application scope, this work designed a series of luminescent polymeric materials only containing carboxyl and amide groups, which were synthesized from poly(methyl vinyl ether maleic anhydride) and 4-(2-aminoethyl)morpholine at different molar ratios (PMVEMA/AML are 1:1, 1:2, and 1:3). The synthesized luminogens exhibited controllable luminescence colors and excellent solubility in various commonly used solvents. Additionally, the polymers can achieve luminescence in dilute solutions, and the maximal luminescence efficiencies can be up to 5.55%. At last, polymer M3 with good biocompatibility and low cytotoxicity can be used to sensitively detect Mg2+ ions in vivo and in vitro. Notably, polymer M3 possesses the ability to target the organelle lysosome in cell imaging.
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高影响因子
MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 2
·1-8
·
IF 5.705
Chen Ying-Chu,Hsu Jui-Hung,Hsu Yu-Kuei
This study introduces a two-step method for the deposition of branched silver nanowires (AgNWs) on fluorine-doped tin oxide (FTO) glass. This material serves as both an active surface-enhanced Raman-scattering (SERS) substrate and as an enzyme-free electrochemical sensor for H 2 O 2 . This dual functionality is systematically studied. The AgNWs as the main trunk were first deposited on FTO by spray-coating. Silver branches were then electrochemically produced on the preformed NWs. Scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectrometry were employed to characterize morphology, composition and microstructure. SERS experiments show that the branched AgNW/FTO substrate exhibits excellent performance in detecting 4-aminothiophenol at an ultra-low concentration of 0.1 fM. Simultaneously, this material displays an excellent electrocatalytic response to H 2 O 2 reduction at a concentration as low as 1 μM. The sensor has a rapid response and two linear analytical ranges that extend from 0.25 to 300 μM, and from 0.3 to 2.6 mM of H 2 O 2 , respectively. The ultrahigh sensitivity and satisfactory reproducibility highlights the merit of this hierarchical AgNW dendritic structure for sensing applications.
Branched silver nanowires can serve as both an active surface-enhanced Raman scattering substrate and as an electrochemical sensor for H 2 O 2 . This dual functionality is systematically investigated.
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高影响因子
Journal of CO2 Utilization
·
2018
·
IF 5.503
Yu Cao,Ran Ma,Ning Wang,Mei-Yan Wang,Xue-Dong Li,Liang-Nian He
Selective hydrogenolysis is a crucial challenge for lignin valorization. A PdCl 2 -catalyzed hydrogenolysis of C OH bond of various lignin β-O-4 alcohol model compounds was developed for preparation of corresponding phenethoxybenzene in 78–98% isolated yield. Notably, the introduction of low-pressure CO 2 (1 MPa) remarkably improves the reaction efficiency and selectivity of phenethoxybenzene. Neither over-reduction of aromatic ring nor further debenzylation was detected. This is understandable that the in situ methylcarbonic acid generated from CO 2 and methanol acts as an acidic catalyst and enhances the leaving ability of hydroxyl group of β-O-4 alcohols. Besides, the present PdCl 2 /CO 2 /MeOH catalyst system proved to be effective for reductive cleavage of C O bonds of β-O-4 ketones, producing ethylbenzenes accompanied with phenols in high yields. Furthermore, this protocol could also be extended to selective hydrodeoxygenation of the carbonyl group to methylene in aromatic ketones. As a sound reaction medium, such in situ CO 2 /MeOH acidic system could be inherently neutralized by depressurizing CO 2 , providing feature advantages for simple post-processing and none waste disposal.
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2018
·
IF 3.974
Lu Wang,Yuan Kang,Siyun Liang,Danying Chen,Qiuyun Zhang,Lixuan Zeng,Jiwen Luo,Feng Jiang
Toxicological effect of freshwater algae co-exposure to Cd and 4-n-nonylphenol (4-n-NP) was seldom reported. In the present study, Chlorella sorokiniana was selected for testing the single and combined effect of Cd and 4-n-NP by detecting the growth inhibition and oxidative stress after exposure for 48 h, 72 h, and 96 h. The combined effects were evaluated by using toxic units (TU) method and concentration addition（CA）model. The synergistic effect of mixture on algal growth inhibition was both observed at 48 h and 72 h, and the additive effect was observed at 96 h. In addition, the significant alterations of superoxide, thiobarbituric acid reactive substances and antioxidant defenses (superoxide dismutase, catalase , glutathione) have been detected. It could be observed that the mixture predominantly lead to synergistic effects in superoxide induction, and the antagonistic effects in the GSH induction. A similar trend between the superoxide induction and growth inhibition were observed, which may indicate that the oxidative effects of Chlorella sorokiniana contributed to the growth inhibition after exposure to Cd and 4-n-NP. These findings may have important implications in the risk assessments of heavy metals and endocrine disruptors in the aquatic environment.
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高影响因子
MICROCHEMICAL JOURNAL
·
2025
·
IF 5.1
Xiang-Cheng Lin,Miaomiao Hu,Minzhe Li,Jian Liu,Qinjie Kou,Rong Huang,Lixian Sun,Changchun Wen
The molecular diagnosis of diseases through the highly sensitive and specific detection of very small amounts of biomarkers in biological samples remains a great challenge, and powerful detection strategies are urgently needed for basic research and clinical applications. Herein, a novel synergistic signal amplification strategy based on Au/Fe 3 O 4 /POPs to integrate magnetic porous composite Fe 3 O 4 /POPs with strong adsorption capabilities for target molecules and gold nanoparticles (AuNPs) with plasmonic properties, is proposed for ultra-high sensitivity and specific Surface-enhanced Raman spectroscopy (SERS) detection of the gastric cancer marker 4-hydroxybenzoic acid (4-HBA). The Au/Fe 3 O 4 /POPs-based SERS assay for gastric cancer-related biomarkers achieved significantly enhanced SERS signals arising from multiple signal amplifications, had good linear calibration from 10 −11 to 10 −5 mol/L, and could detect 4-HBA with a limit of detection (LOD) as low as 1.52 × 10 −12 mol/L. The detection of 4-HBA doped serum exhibited good specificity, homogeneity, and reliability. This material is easy to synthesize and simplifies the sample pretreatment process. This innovative SERS substrate is promising for the rapid detection of disease markers, particularly for early diagnosis and monitoring the effectiveness of gastric cancer treatments.
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