ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Jian Fang,Zhi-Qiang Wang,Xinjia Wei,Yuan Ma,Honghui Gong,Xue-Qing Gong,Zhenshan Hou
The N-formylation reaction of various amines with CO2 is a promising method to utilize CO2 for the production of high value-added chemicals. Herein, an efficient Ru catalyst system consisting of Ru complex ([PPN][Ru(CO)3Cl3]) and the ionic liquid 1-butyl-3-methylimidazolium hydrogen phosphate ([Bmim]2[HPO4]), has been developed for the N-formylation reaction. Activity evaluation demonstrated that the catalyst system exhibited good to excellent yields of formamides under very mild conditions with the assistance of ionic liquids (ILs). Furthermore, the catalyst system could be reused at least five times with a slight loss of activity in N-formylmorpholine production. Further characterization by 1H nuclear magnetic resonance (NMR), 13C NMR, and density functional theory (DFT) calculations showed that the ILs ([Bmim]2[HPO4]) could facilitate the adsorption of CO2 by a concerted action of both cations and anions of the ILs to form phosphorus carbonate intermediate, thus effectively promoting the reaction. DFT calculations demonstrated that the formation of Ru–H was the first step, and then the CO2 absorbed by [Bmim]2[HPO4] inserted directly into Ru–H by cooperating with the Ru sites to form HCOO– species. After that, formate species dissociated from Ru catalysts and dehydrated to form formamides by the catalytic action of Ru complex and the basic IL.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Yibo Tang,Ying Lei,Kang Tong,Tong Yang,Tiantian Fu,Yang Xiang,Shulin Zhang,Yujun Si,Chaozhong Guo
Fe, N-doped graphene-like carbon layers-wrapped carbon black composite (L-Fe-AD+C) was developed by pyrolyzing the mixture of Fe-adenine precursors and conductive carbon black as an efficient catalyst to oxygen reduction reaction (ORR). Graphitic N sites with more ORR activity are preferentially formed due to the facilitation of metallic Fe. Furthermore, graphene-like ultra-thin networks wrapped around nanoparticles of carbon black greatly increase the exposure of active sites and construct continuous diffusion channels favorable for the transfer of substances. As a result, the as-prepared L-Fe-AD+C exhibits an excellent ORR activity in alkaline electrolyte with a high half wave potential (0.88 V), and superior selectivity together with admirable stability, which are comparable to those of the benchmark Pt/C catalyst. More encouragingly, the L-Fe-AD+C can serve as an efficient cathode catalyst in a zinc-air battery, which reaches a peak power density of 221 mW cm −2 approximating to that of Pt/C catalyst (236 mW cm −2 ). The battery also shows a steady discharge voltage plateau of 1.26 V and specific capacity of 799 mAh g −1 at a discharge current density of 10 mA cm −2 . The results suggest the considerable potential of the L-Fe-AD+C catalyst to replace precious metal catalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 15
·B1491
·
IF 3.12
Xiaoying Liu,Wenbin Li,Tianqin Zeng,Silu Zhang,Bijing Zhou,Muyi Li,Peng Zhao,Chang Peng
Heteroatom doped carbon materials have attracted intense attention in constructing electrochemical sensors because of their outstanding electrocatalytic performance. Up to now, most of the researches were focused on the electrochemical application of single heteroatom doped carbon microspheres. In this work, N, P-co-doped carbon microspheres (NP-CMs) modified electrode was developed as highly sensitive electrochemical sensor for acetaminophen. NP-CMs were acquired by the calcination of products from the one-pot reaction of dopamine and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Experimental results revealed that NP-CMs showed better electrocatalytic performance compared with N-doped carbon microspheres. Under the optimal conditions, the response of NP-CMs/GCE showed a linear relationship with acetaminophen concentration from 0.07 μM to 30 μM, the linear equation was Y = 0.01356X+0.7417 and the detection limit was 40 nM (S/N = 3). The recoveries of the NP-CMs modified GCE for the assay of acetaminophen in human serum samples were from 94.0% to 106.0%. It was believed that N, P-co-doped carbon microspheres have a great potential in the design of novel pharmaceutical analysis methods.
研究领域:
分析化学
·
材料科学
·
药学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2017
·Vol. 35
·期 10
·1268-1275
·
IF 1.692
Peng Xin,Liu Tian-qi,Shang Cong,Jiao Chen,Wang Hui-liang
Simple preparation of stimuli-responsive hydrogels with good mechanical properties and mild stimuliresponsiveness is essential for their applications as smart soft robots. Mechanically strong Janus poly( N -isopropylacrylamide)/graphene oxide (PNIPAM/GO) nanocomposite hydrogels with stimuli-responsive bending behaviors are prepared through a simple one-step method by using molds made of a Teflon plate and a glass plate. Residual oxygen in the air bubbles on the Teflon plate surface affects the polymerization and hence the cross-linking density, leading to the different swelling/deswelling rates of the two sides of the gels. Therefore, the hydrogels exhibit bending/unbending behaviors upon heating/cooling in water. The incorporation of GO nanosheets dramatically enhances the mechanical properties of Janus hydrogels. Meanwhile, the photo-responsive property of the GO nanosheets also imparts the hydrogels with remotecontrollable deformation under IR irradiation. The application of the Janus PNIPAM/GO hydrogels as thermo-responsive grippers is demonstrated.
研究领域:
材料科学
·
智能材料
·
生物医学工程
✓ 已验证
DOI
高影响因子
PHYSICS OF FLUIDS
·
2021
·Vol. 33
·期 2
·
IF 3.521
Zhao Wenjing,Ma Hongzhi,Ji Wenjie,Li Weibin,Wang Jin,Yuan Quanzi,Wang Yuren,Lan Ding
Flows of thin fluid layers spreading, which have a distinguished history, have been studied since the days of Reynolds, who was among the early researchers to examine flows. Different from surfactant-driven spreading, which is currently the most common subject of study, we observe the spreading process of n -hexadecane driven by volatile silicone oil at the surface of the aqueous substrates and explore the influence of Marangoni flow caused by surface tension gradient on liquid-driven spreading. We find that on different substrates, the initial state of n -hexadecane is different, and there are two instability patterns during the spreading, subsequently, which are analyzed theoretically. While the n -hexadecane drop stationed on the liquid surface is small, it is driven to form a rim and then breaks up into beads, which shows the Rayleigh–Plateau instability patterns. When we put the n -hexadecane drop on the surface of the saturated sodium chloride solution, which spreads out more, it is driven to form a circular belt first and fingering instability subsequently occurs at the inner edge of the circular belt.
研究领域:
流体力学
·
物理化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2018
·Vol. 31
·期 6
·789-798
·
IF 0.586
Wang Xiao-yan,Fan Hai-yan,Ye Xiao-dong,Liu Shi-lin,Zhang Guang-zhao
Two narrowly-distributed poly( N - isopropylacrylamide) (PNIPAM) samples were prepared via atom transfer radical polymerization (ATRP) with a novel dansyl functionalized initiator. The other end of the PNIPAM was functionalized by dabcyl group via click reaction. From the static fluorescence measurements, the fluorescence intensity of dansyl group and energy transfer efficiency between dansyl and dabcyl groups increased when the temperature increased from 36 °C to 45 °C, indicating that the microenvironment surrounding dansyl became hydrophobic and the distance between dansyl and dabcyl decreased. The kinetics of the conformational change of the dye-labeled PNIPAM was studied by a home-made laser-induced temperature jump device with fluorescent measurement. Our results revealed that the characteristic transition time was 3.8 and 5.8 ms for PNIPAM with degrees of polymerization of 85 and 142, respectively, indicating that the characteristic transition time was related to the chain length. Besides, characteristic transition time for the change of the energy transfer efficiency was 2.9 ms for PNIPAM with the degree of polymerization of 85, suggesting that the energy transfer efficiency change was faster than the fluorescence intensity change of dansyl group.
研究领域:
高分子化学
·
生物物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2013
·
IF 5.787
Lin Guo,Yu Fan,Xiaojun Bao,Gang Shi,Haiyan Liu
Silicoaluminophosphate (SAPO-11) samples with enhanced acidity were synthesized by two-stage crystallization in the presence of dodecyltrimethylammonium bromide (DoTAB), in which the Si source was added after the aluminophosphate framework was formed. The structure, elemental composition, acidity, Si environment, and n-octane di-branched isomerization of the as-synthesized SAPO-11 with small crystallites were investigated. The results showed that compared with the conventional one-stage crystallization, the two-stage crystallization produced more Si borders in the resulting SAPO-11. Among the SAPO-11 samples synthesized by two-stage crystallization, the SAPO-11 with the optimal DoTAB content (mol(DoTAB)/mol(SiO 2 ) = 0.015) had the most Si( n Al) (0 < n < 4) species with moderate and strong Brønsted acidity. The catalyst based on the small crystallite SAPO-11 containing a greater number of moderate and strong Brønsted acid sites exhibited superior performance for n-octane di-branched isomerization. This two-stage DoTAB-assisted crystallization opens a new route to enhancing the SAPO-11 acidity and can be extended to the other SAPO molecular sieves.
研究领域:
化学工程
·
催化科学
·
材料科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Mengshuai Liu,Bo Liu,Shifa Zhong,Lei Shi,Lin Liang,Jianmin Sun
In this contribution, a series of N-heterocyclic compounds cooperated with ZnBr2 catalyst for chemical fixation of CO2 to cyclic carbonates was developed without utilization of additional organic solvents. It was found that the catalytic activity of N-heterocyclic compounds could be obviously enhanced in the presence of ZnBr2, and the N-methylimidazole (Mim)/ZnBr2 catalytic system was the most efficient among the catalysts employed. Under the optimum reaction conditions, 99% yield of propylene carbonate was achieved with TOF of 474 h–1, and the catalysts were also versatile for CO2 cycloaddition with less active epoxides such as styrene oxide and cyclohexene oxide. Furthermore, a possible synergistic catalytic mechanism was proposed. Moreover, the rate constants were determined as a function of reaction temperature in the range of 130–160 °C, the activation energy was determined to be 41.1 kJ·mol–1, and the kinetic equation on the synthesis of propylene carbonate catalyzed by Mim/ZnBr2 was also obtained.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 73
·59286-59291
·
IF 3.84
Shifeng Li,Min Xing,Haiyan Wang,Li Zhang,Yiman Zhong,Lei Chen
In this work, water-soluble ZnS quantum dots (QDs) modified with 3-mercaptopropionic acid (MPA), L-cysteine (L-Cys) and thioglycolic acid (TGA) were synthesized. The nanostructure and optical properties were characterized by X-ray powder diffraction (XRD), Transmission electron microscopy (TEM), UV-Vis absorption spectrum and fluorescence spectrum. Through the study of the ZnS QDs effects on the chemiluminescence (CL) system of luminol, we found that ZnS QDs could obviously enhance the CL of the luminol–N-bromosuccinimide (NBS) system in an alkaline medium. At the optimal experimental conditions, we researched the impact of 17 kinds of amino acids on this system. It was found that L-tryptophan (Trp) and L-tyrosine (Tyr) had significantly inhibitory effects on luminol–NBS–ZnS QDs CL. Based on the inhibitory effects, a novel CL method with a wider linear range and lower detection limit for determination of Trp and Tyr was developed. The detection limits were 1.5 × 10−11 g mL−1 and 2.0 × 10−10 g mL−1, respectively. The possible CL reaction mechanism was also discussed briefly.
研究领域:
分析化学
·
生物化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
He-Qiang Chang,Guo-Hua Zhang,Kuo-Chih Chou
Electrochemical water splitting is considered a sustainable route for the hydrogen industry. In this work, Mo 2 C/MoC heterostructure supported on N -doped carbon (Mo 2 C/MoC@NC) was prepared via a carbonization strategy. For the product (Mo 2 C/MoC@NC-1-2) fabricated with a g-C 3 N 4 / ammonium molybdate tetrahydrate molar ratio of 1:2 at 700 °C under 10%CH 4 /H 2 atmosphere, a high stability and good HER activity with a η 10 of 113 mV in 1M KOH were achieved. To further enhance the catalytic performance of the synthesized Mo 2 C/MoC@NC, the phosphating strategy was proposed for the preparation of Mo 2 C/MoC/MoP heterostructure supported on N-doped carbon (Mo 2 C/MoC/MoP@NC). When the precursor Mo 2 C/MoC@NC-1-2 was phosphated at 650 °C with a heating rate of 5 °C min −1 and kept for 0 min, the as-synthesized Mo 2 C/MoC/MoP@NC-650-0 exhibits good HER catalytic activity with a pretty low η 10 of 78 mV, a j 0 of 0.398 mA cm −2 , and a Tafel slope of 52 mV dec −1 in 1M KOH. This good activity of HER can be ascribed to the N-doped carbon as substrate and the construction of transition metal-based heterostructures.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Di Pang,Yue Liu,Haiou Song,Duozhe Chen,Weiqing Zhu,Rumeng Liu,Hu Yang,Aimin Li,Shupeng Zhang
A trace Ti 3+ - and N-codoped TiO 2 nanotube array (TiON) anode is fabricated by electrochemical reduction after introducing nitrogen into the TiON. The TiON anode material is characterized by scanning electron microscopy, X-ray diffraction, Raman spectra and X-ray photoelectron spectroscopy. Electrochemical analyses of TiON, including cyclic voltammetry, electrochemical impedance spectroscopy and linear scan voltammetry, are conducted to confirm that the electrochemical performance could be significantly improved by electrochemical reduction and N doping. The achieved TiON anode is applied to the electrocatalytic oxidation of tetracycline (TC) and metronidazole (MNZ). The effect of applied current density, initial solution pH and initial TC/MNZ concentration on the reaction kinetics is systematically evaluated to obtain the optimal conditions. The degradation processes follow an apparent first-order kinetic model in all conditions. After 240 min of reaction time, the TC removal efficiency, chemical oxygen demand (COD) removal rate and total organic carbon (TOC) removal rate are >99%, 92.86% and 74.98%, respectively. The MNZ removal efficiency, COD and TOC removal rate achieved are >99%, 93.03% and 79.30%, respectively, after 240 min of degradation. The excellent removal efficiency of TC and MNZ indicates that this TiON anode is a promising material in the practical application of removing antibiotics from water.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2020
·
IF 6.551
Changwei Li,Zhefeng Gu,Songming Zhu,Dezhao Liu
This study evaluated the contribution of biotic and abiotic routes to the 17 β -estradiol (E2) removal in moving bed biofilm reactors (MBBRs), and uncovered the interrelation between the E2 removal routes and biofilm characteristics, which was not researched in previous literature. Three MBBRs with different C/N ratios (0 for C/N 0 ; 2 for C/N 2 ; and 5 for C/N 5 ) were operated in continuous mode. A 65-day degradation demonstrated that the MBBRs had high potential to remove E2 regardless of the C/N (E2 removal greater than 99% for all MBBRs; P > 0.05). Further batch tests showed that the E2 removal mainly resulted from heterotrophic activities for all MBBRs, accounting for approximately 85% for all MBBRs (P > 0.05), followed by nitrification (10–11%) and adsorption (4–5%). Importantly, lower adhesive force likely led to higher E2 adsorption onto biofilms. Besides, enhanced ammonia oxidizing rate (AOR) was consistent with the high contribution of nitrification to the E2 attenuation. Importantly, heterotrophic activity was positively correlated with its contribution to E2 removal (r = 0.99, P < 0.05). To sum, the results obtained in this study helped to understand the E2 removal routes in nitrifying biofilm systems.
研究领域:
环境科学
·
微生物学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）