Environmental Science-Nano
·
2024
·Vol. 11
·期 7
·3092-3103
·
IF 5.8
Manoj Kumar Panjwani,Feiyu Gao,Ting He,Pan Gao,Feng Xiao,Shaoxia Yang
M–Nx single-atom catalysts (SACs) with a high coordination number (x > 4) are effective catalysts for eliminating organic pollutants, while the origin of SACs with high activity still remains elusive. In this work, we successfully synthesized an Fe–N5 SAC with axial N coordination, which exhibited exceptional catalytic performance by peroxymonosulfate (PMS) activation for degrading 4-chlorophenol (4-CP) in a wide pH range (4.0–10.0). The rate constant of Fe–N5 (2.99 min−1) was 6.36 times higher than that of Fe–N4, and the turnover frequency (TOF) of Fe–N5 was found to be 4–149 times higher than those of state-of-the-art SACs and nanocatalysts reported in the literature for 4-CP degradation by PMS activation. Moreover, Fe–N5 was not significantly affected by coexisting substances (HA, HCO3−, SO42−, H2PO4−, NO3−, and Cl−) and had satisfactory degradation efficiency for various chlorophenols. Electron paramagnetic resonance (EPR), quenching experiments, and radical probe experiments demonstrated that 1O2 played a key role in the Fe–N5/PMS system for 4-CP degradation. Density functional theory calculations confirmed that a narrower gap between the Fe-3d band center and Fermi level enhanced the electron transfer in Fe–N5, which resulted in promoted PMS activation. In addition, the Fe–N5/PMS system showed good potential for application in real wastewater. The above findings offer important implications for the future of coordination chemistry in designing M–Nx–C SACs (x > 4), highlighting their practical applications in environmental remediation.
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Analytical Methods
·
2018
·Vol. 10
·期 45
·5372-5379
·
IF 2.073
Odoom Jibrael Kingsford,Junjuan Qian,Depeng Zhang,Yinhui Yi,Gangbing Zhu
The occurrence of 1-chloro-4-nitrobenzene (CNB) in the environment due to increased agricultural and economic activities worldwide has been a serious concern for various environmental agencies; hence the qualitative and quantitative determination of CNB is of great significance. In this study, we took into consideration the features of carbon nanohorns (CNHs), such as high surface area and electron transfer ability, and β-cyclodextrin (β-CD), such as high host–guest recognition ability with a hydrophilic outer layer, to design a highly sensitive electrochemical sensor for detecting CNB by preparing CNHs and β-CD nanohybrids through a simple ultrasonication process. The outcome of our study revealed that the CNHs/β-CD nanohybrid modified electrode is an excellent electrochemical sensor for CNB. Under the optimized conditions, the experimental results show a considerable linear response range, unsubstantial interference from familiar organic and inorganic compounds and a detection limit of 9.0 nM.
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JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2015
·
IF 2.495
Yaping Wang,Song Zhang,Simei Sun,Kai Liu,Bing Zhang
The ultrafast dynamics of S 2 -excited trans -4-diethylaminoazobenzene ( trans -4-DEAAB) is investigated in solution by femtosecond transient absorption spectroscopy combined with quantum chemical calculations. Following excitation, the internal conversion from the S 2 state to the S 1 state occurs directly with time constant of ∼0.10 ps. The cis isomer is observed by the partial recovery of ground-state bleach in 450–480 nm and the permanent positive absorption in 480–550 nm. The time constant of <1 ps is assigned to the lifetime of the S 1 state which decays by isomerization to the cis -isomer hot S 0 state and internal conversion to the trans -isomer hot S 0 state. The photoisomerization is deduced by inversion mechanism because of the independence between the viscosity and the S 1 -state lifetime. The vibrational cooling of the hot S 0 state of cis -4-DEAAB occurs with ∼15 ps in acetone but is shortened to ∼6 ps in alcohols solvents. This shortening is due to the H-bond which forms easily in protic solvent and accelerates the flow of vibrational energy between solute and solvent.
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Energy Storage Materials
·
2019
·
IF 0
Jianwei Zhang,Shuanjin Wang,Dongmei Han,Min Xiao,Luyi Sun,Yuezhong Meng
A novel single ion conducting polymer electrolyte is synthesized via a facile and efficient one-step ultraviolet initiated thiol-ene click reaction. The monomers of lithium (4-styrenesulfonyl) (trifluoromethanesulfonyl) imide, pentaerythritol tetrakis (2-mercaptoacetate) and pentaerythritol tetraacrylate are polymerized to be a crosslinked network structured polymer within a polypropylene nonwoven fabric supporting membrane by a photo-initiated thiol-ene click reaction. Upon solvent soaking, the obtained single ion conducting polymer electrolyte exhibits high ionic conductivity (0.84 mS cm −1 at room temperature), very high lithium ion transference number of 0.93, wide electrochemical window up to 5.2 V (vs. Li + /Li) and well compatibility with lithium metal anode . The corresponding LiFePO 4 /Li cell assembled with the prepared polymer electrolyte shows excellent rate capability and prominent cycling performance with the capacity retention rate of 83% after 400 cycles at 1 C. Therefore, the synthesized single ion conducting polymer electrolyte owns great potential for practical application in lithium ion batteries .
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Nanomaterials
·
2020
·Vol. 10
·期 3
·426
·
IF 4.324
Chen Hou,Dongyan Zhao,Wenqiang Chen,Hao Li,Sufeng Zhang,Chen Liang
In this work, magnetic CuFe2O4/Ag nanoparticles activated by porous covalent organic frameworks (COF) was fabricated to evaluate the heterogenous reduction of 4-nitrophenol (4-NP). The core-shell CuFe2O4/Ag@COF was successfully prepared by polydopamine reduction of silver ions on CuFe2O4nanoparticles, followed by COF layer condensation. By integrating the intrinsic characteristics of the magnetic CuFe2O4/Ag core and COF layer, the obtained nanocomposite exhibited features of high specific surface area (464.21 m2g−1), ordered mesoporous structure, strong environment stability, as well as fast magnetic response. Accordingly, the CuFe2O4/Ag@COF catalyst showed good affinity towards 4-NP via π-π stacking interactions and possessed enhanced catalytic activity compared with CuFe2O4/Ag and CuFe2O4@COF. The pseudo-first-order rate constant of CuFe2O4/Ag@COF (0.77 min−1) is 3 and 5 times higher than CuFe2O4/Ag and CuFe2O4@COF, respectively. The characteristics of bi-catalytic CuFe2O4/Ag and the porous COF shell of CuFe2O4/Ag@COF made a contribution to improve the activity of 4-NP reduction. The present work demonstrated a facile strategy to fabricate COF-activated nano-catalysts with enhanced performance in the fields of nitrophenolic wastewater treatment.Keywords:magnetic covalent organic frameworks;nanocomposite;core-shell;p-nitrophenol;reduction
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DOI
PubMed
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Yao Tong,Tianhua Yang,Jian Wang,Bingshuo Li,Haijun Zhang,Rundong Li
Hydrodeoxygenation (HDO) of lignin-derived phenolic compounds plays a crucial role in the production of renewable biofuels. In this regard, a series of different Co@NC catalysts were prepared with ZIF-67 as a sacrificial template by modulating the catalyst pyrolysis temperature and used for the catalytic hydrodeoxygenation of lignin-derived phenolic model compound 4-ethylphenol for the preparation of cyclohexanols/ cyclohexanes. The results showed that the low-temperature pyrolysis will retain a large number of CoO x compounds, which led to a high dispersion of Co. For Co@NC catalysts, the uniformly dispersed Co component facilitated the adsorption and transfer of hydrogen, and the exposed surface of the carrier promoted the adsorption of reactants. The pyrolysis temperature also played a crucial role in the differences in catalyst crystal surface, specific surface area, acid strength distribution and oxygen vacancies. Co@NC catalyst prepared at 600 °C has a stronger hydrogen absorption capacity, the largest specific surface area and a higher number of oxygen vacancies. Therefore, the Co@NC-600 catalyst showed the best HDO activity. Under the mild conditions (220 °C, 2.5 h and 3 MPa H 2 ), the conversion of 4-ethylphenol was close to 100 %, and the selectivities of 4-ethylcyclohexanol and ethylcyclohexane were 62.7 % and 10.8 %, respectively.
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高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Shiyu Wei,Guochao Xu,Jieyu Zhou,Ye Ni
Baeyer-Villiger monooxygenases are recognized as valuable tools for biooxidative synthesis of chiral sulfoxides. In this work, a novel HAPMO ortholog from Pseudomonas fluorescens (HAPMO Pf ) was identified by genome mining. Evolutionary relationship and sequence analysis revealed that HAPMO Pf belongs to the family of typical type I BVMOs. HAPMO Pf has a low K M value (0.025 mM) toward 4-hydroxyacetophenone, and a half-life of 24 h at 30 °C and pH 9.0. HAPMO Pf exhibited distinct activity toward aromatic ketones as well as various thioethers, such as methyl phenyl sulfide and bromo‑methyl phenyl sulfide. The highest activities of HAPMO Pf was 1.47 U·mg −1 toward 4-hydroxyacetophenone among tested ketone and thioether substrates. Furthermore, over 95% enantioselectivity was determined toward methyl phenyl sulfides with ortho, meta, and para -substituents (Cl, Br, CHO, NH 2 ). Therefore, HAPMO Pf is a promising biocatalyst for the synthesis of aromatic esters and chiral sulfoxides.
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DESALINATION
·
2020
·
IF 7.098
Shushan Yuan,Gang Zhang,Junyong Zhu,Jie Yang,Suilin Liu,Bart Van der Bruggen
Nanoporous materials with intrinsic pores have attracted considerable attention to synthesize thin film composite (TFC) membrane. However, incorporating them in the matrix of a membrane did not achieve the full potential of their well-defined intrinsic pores in separation. In this work, entirely resorcin[4]arene (RA) macrocycle based membranes were synthesized by using four types of resorcin[4]arene macrocycles with different lengths of fatty chains. The effect of RA concentration and RA chemical composition on nanofiltration (NF) performance of the prepared membranes was investigated. It was found that the membrane synthesized from RA-3R with a concentration of 0.73 wt% has the optimal NF performance. This membrane had an ultrathin polyarylate selective layer (4.3 nm), supported on a Kevlar hydrogel membrane. Due to the well-defined homogeneous pores, it showed an excellent NF performance, having a water permeability of 26.2 L m −2 h −1 bar −1 while maintaining 95.6% rejection of Na 2 SO 4 . It also demonstrates high rejections of various dyes. These properties are higher than the majority of other nanoporous materials-based membranes. Our study highlights the potential application of resorcinarene macrocycles in the synthesis of TFC membranes for nanofiltration.
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RUSSIAN JOURNAL OF ELECTROCHEMISTRY
·
2021
·Vol. 56
·期 12
·984-988
·
IF 1.078
Zhixing Xiong,Ouyang Dilan,Zhang Wenbin
Abstract The use of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and 4-acetamido-TEMPO (ACT) for electrochemical oxidation of L-sodium lactate (SL) was comparatively investigated by cyclic voltammetry, and it was proved that ACT is more effective as a mediator in these electrocatalytic reactions. A comprehensive investigation of electrooxidation performance of ACT toward SL through investigating the effect of pH, concentration of SL, the sensitivity of SL using this electroanalytical method was calculated to be 2.78 μA cm –2 /mM, the catalytic rate constant was determined to be 51.7 L/(mol s) by using chronoamperometry.
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CHEMICAL PAPERS
·
2016
·Vol. 70
·期 11
·1521-1528
·
IF 1.326
Mei-Hang Chen,Xiao-Bing Wang,Bang-Cheng Tang,Xun Zhang
A series of novel Schiff base derivatives containing 4(3 H )-quinazolinone moiety were synthesised and their antibacterial activities against tobacco and tomato bacterial wilts evaluated in vitro. Out of the synthesised compounds, 5g , 5j , 5n , 5m and 5p exhibited excellent antibacterial activities against tobacco bacterial wilt, with half maximal effective concentrations (EC 50 ): 160.34, 158.03, 125.94, 148.09 and 133.67 (all in μg mL −1 ), respectively, which were better than the EC 50 of thiodiazole–copper (216.70 μg mL −1 ). Compounds 5j , 5n and 5o also showed good antibacterial activities against tomato bacterial wilt, with EC 50 of 95.20, 90.03 and 83.21 (all in μg mL −1 ) respectively, which were better than the EC 50 of thiodiazole–copper (99.80 μg mL −1 ). These compounds may prove to be useful as potential antibacterial agents.
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International Journal of Applied Ceramic Technology
·
2021
·Vol. 18
·期 5
·1570-1581
·
IF 1.968
Yangyi Xu,Xiaohui Wang,Yunge Wei,Yuanxi Liu,Guifang Li
CaGd 2 (WO 4 ) 4 :Eu 3+ phosphors with controllable morphology were synthesized via the hydrothermal method. The influences of pH value, reaction time and Eu 3+ concentration on the crystal structure, morphology, and photoluminescence properties of CaGd 2 (WO 4 ) 4 :Eu 3+ were studied. The pure tetragonal structure CaGd 2 (WO 4 ) 4 is obtained when the pH value is 8 and 9. Furthermore, by altering the pH value of the reaction solution, the morphologies of the CaGd 2 (WO 4 ) 4 :Eu 3+ phosphors evolve from spindle-shaped grains to tetragonal plate-like grains and finally to aggregated bulk particles. Under the 394 nm excitation, the phosphors display a bright red emission corresponding to the characteristic 4 f -4 f transitions of Eu 3+ , and the intensity of emission peaks depends mainly on the pH value, the reaction time, and the Eu 3+ concentration. The optimum photoluminescence performance is achieved for CaGd 2- x (WO 4 ) 4 : x Eu 3+ ( x = 1) phosphor synthesized at pH = 8 under the reaction time of 16 h. Finally, the thermal stability of the phosphors is analyzed at different ambient temperatures.
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Journal of Flow Chemistry
·
2018
·Vol. 8
·期 1
·29-34
·
IF 1.658
Yu Jiangang,Xu Jianguo,Li Jie,Jin Yi,Xu Wanghui,Yu Zhiqun,Lv Yanwen
A two-step flow reactor has been set up for an expeditious synthesis of 4-benzylidene-pyrazol-5-one derivatives. This procedure involved cyclization of aromatic hydrazine/ β -keto ester and subsequent Knoevenagel condensation reaction with aromatic aldehydes in tandem without isolation of intermediates. Residence time was reduced to less than 2 min in total through conducting this reaction at a relatively high temperature. Accordingly, 15 samples were achieved and isolated in moderate to excellent yields.
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