Journal of Energy Chemistry
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2013
·Vol. 22
·期 3
·363-367
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IF 0
Zhenfeng Diao,Bin Li,Bing Yu,Anhua Liu,Liangnian He
The selective aerobic oxidation of alkynes to corresponding α,β-acetylenic ketones was achieved in polyethylene glycol/dense CO 2 /O 2 biphasic system without any catalyst or additive. The effects of reaction parameters, e.g. temperature, CO 2 pressure, PEG molecular weight and loading on the reaction were carefully examined. Moreover, various substrates worked well in the presence of PEG1000 under 5 MPa of CO 2 and 2 MPa of O 2 at 100 °C for 12 to 24 h and acceptable yield and selectivity could be obtained in most cases. Preliminary mechanistic investigations were also discussed.
研究领域:
有机化学
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绿色化学
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氧化催化
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可持续溶剂
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Journal of Optics
·
2015
·Vol. 17
·期 7
·075003
·
IF 2.059
Yongan Yang,Yuyang Wang,Xiaoyong Zhang,Guohua Qi,Shuping Xu,Weiqing Xu
Ag nanoparticles and nanostructured surfaces have been widely used as surface-enhanced Raman scattering (SERS) substrates, which can enhance the Raman signals when molecules are adsorbed on the surface of Ag by the effect of Ag-thiol bonds. In this paper, we propose an efficient method to remove the molecules adsorbed on Ag with sodium borohydride solution, providing a protocol to realize a reproducible and practicable Ag SERS substrate. A theoretical density function theory approach has been used to explain the mechanism of desorption.
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NEW CARBON MATERIALS
·
2021
·Vol. 35
·期 6
·722-730
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IF 1.905
Yuan-shuo Peng,Jian-xiao Yang,Kui Shi,Jian-guang Guo,Hui Zhu,Xuan-ke Li
The stabilization of isotropic pitch (IP)-derived pitch fibers (PFs) and mesophase pitch (MP)-derived PFsin air was performed at different heating rates and with different final stabilization temperatures. The stabilized fibers (SFs) and carbon fibers (CFs) were characterized by elemental analysis, FT-IR, TG-MS and SEM to investigate the influence of the degree of oxidation of the SFs on the microstructures and mechanical properties of the CFs. Results showed that a slow heating rate during stabilization was beneficial to the oxidative cross-linking of PFs, and the corresponding CFs had a higher carbonization yield and tensile strength at the lower heating rate. When both IPF and MPF were stabilized at 270 o C, the two resulting CFs all reached their optimal performance. In addition, the FTIR peak intensity ratio of the C=O band at about 1700 cm –1 to the C=C band at 1600 cm –1 of the SFs had a good relationship to the carbonization yield and tensile strength of the CFs, and thiscan beusedto optimize the degree of oxidation of the SFs. Moreover, insufficiently stabilized fibers released a great deal of H 2 and CH 4 , causing some porosity in the resulting CFs with a low tensile strength, especially forthe insufficiently stabilized IPCF. While over-stabilized fibers released a large amount of CO and CO 2 , causing cracked textures in the corresponding CFs, especially inthe over-stabilizedMPCF. Therefore, this research into the stabilization and carbonization behaviors of pitch fibers has great significance for improving the mechanical properties of pitch-based CFs.
研究领域:
材料科学
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碳材料
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高分子加工
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热处理
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高影响因子
International Journal of Electrochemical Science
·
2023
·Vol. 8
·期 12
·12735-12740
·
IF 1.5
Binbin Zhang,Yuan Zhou,Xiang Li,Xiufeng Ren,Hongen Nian,Yue Shen,Qiang Yun
FTIR (Fourier transformed infrared) spectra have been collected and analyzed for solutions of lithium tetrafluoroborate in propylene carbonate (PC). It has been shown that the carbonyl stretch, symmetric ring deformation stretch and ring deformation stretch bands for PC is very sensitive to the interaction between Li + and the solvent molecule. Their half-peak breadth increases and bands split with the addition of LiBF 4 , indicating that a strong interaction exists between Li + and PC molecule mainly through the oxygen group of C=O and ring position of PC.
研究领域:
物理化学
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光谱学
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电解质溶液
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电池材料
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高影响因子
NEW CARBON MATERIALS
·
2026
·Vol. 41
·期 3
·583-595
·
IF 7.2
Yunping Hu,Daixuan Gong,Meijie Qu,Ping Tang,Yuezhen Bin
A balance between electrical and magnetic properties is critical for electromagnetic shielding materials to achieve excellent electromagnetic interference (EMI) shielding and attenuation effectiveness across a broad frequency range. We have prepared free-standing buckypaper films (BPFP) decorated with Fe 3 O 4 particles and polyaniline (PANI) by a simple two-step method to meet this requirement. First, buckypaper films decorated with Fe 3 O 4 (BPF) were synthesized by the coprecipitation of Fe 2+ /Fe 3+ ions on buckypaper (BP) which was then coated with a polyaniline layer by the in situ polymerization of aniline monomers. Magnetic characterization revealed that the BPF and BPFP films had saturation magnetization ( M s ) values of 14.3 emu g −1 and 13.0 emu g −1 , respectively, confirming retention of the magnetic phase. The addition of Fe 3 O 4 nanoparticles and polyaniline to BP (30 μm) increased both the magnetic and dielectric losses due to the increased interfacial polarizations and anisotropy energy. 41 μm-thick BPF and BPFP films had an absorption-dominated shielding effectiveness of 35.1 dB and 36.4 dB, respectively, across the 5.85-18 GHz frequency band. These values are respectively 12.9% and 17.0% greater than that of pristine BP, highlighting the positive effect of Fe 3 O 4 -PANI heterostructures on electromagnetic wave dissipation. These films also had the tensile strength, flexibility, and lightness of BP, demonstrating exceptional promise for next-generation electromagnetic shielding materials.
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CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Hongfang Wang,Leitao Xu,Jingcheng Wu,Peng Zhou,Shasha Tao,Yuxuan Lu,Xianwen Wu,Shuangyin Wang,Yuqin Zou
5-Hydroxymethylfurfural (HMF) electrooxidation in neutral conditions is a promising strategy to suppress the formation of humins and corrosive effects on electrochemical devices. However, scarce studies have been reported in neutral media due to the deficiency in electrophilic oxygen (eg OH – ) required for the activation of HMF. Herein, 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO)/Co 3 O 4 was utilized to co-catalyze HMF in neutral media, successfully achieving 2,5-furandicarboxylic acid (FDCA) with yield > 99%. It was found that TEMPO could promote HMF dehydrogenation to 2,5-diformylfuran (DFF) and simultaneously activated water via hydrogen-bonding interactions. As a result, the formation of OH* in neutral electrolytes was favored, which was absorbed by electrogenerated active Co species to facilitate subsequent conversion of formyl-group-involved intermediates to FDCA. This work provides a current understanding of the catalytic mechanism for HMFOR in neutral media and guides the design of highly efficient electrocatalysts for biomass upgrading.
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高影响因子
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
·
2023
·
IF 4.5
Jun-lian WANG,Lu LIU,Guo-dong XU,Pei-long WANG,Guo-yong HUANG,Feng-shan YU
To seek more efficient extractant for Pd recovery from leaching solution of spent automotive catalysts, a new compound N-methyl-N-isopropyl octanthioamide (TA-813) was synthesized and characterized through FT-IR, 1 H NMR, ESI-MS and elemental analysis. Its extraction and stripping behaviors for Pd were studied. To evaluate its reusability performance, extraction−stripping cycles were carried out. Finally, TA-813 was applied to separating Pd from simulated leaching solution of spent automotive catalysts. TA-813 shows fast extraction kinetics, high extraction efficiency and specific selectivity for Pd. During extraction two TA-813 molecules coordinate with one Pd. The loaded Pd in the organic phase is efficiently stripped by neutral and acidic thiourea solutions. TA-813 shows no loss in activity after eight extraction−stripping cycles. Even from simulated leaching solution of spent automotive catalysts, in which the concentrations of some purities (La, Ce, Mg, Al) are much higher than that of Pd, Pd is still selectively extracted.
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高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Jingyi Chen,Chao Zhou,Hongyu Liu,Ping Li,Yonghai Song,Fugang Xu
A self-powered electrochemical sensor (SPS) has been designed for sensitive detection of glucose based on the glucose oxidase (GOD)/polyvinyl ferrocene (PVF)/ poly(diallyldimethylammonium chloride) (PDDA -reduced graphene oxide (RGO)/glassy carbon electrode (GCE) as a bioanode and bilirubin oxidase (BOD)/PDDA-RGO/GCE as a biocathode. The signal amplification of electron mediator in the electrochemical anode has been investigated in details. The results exhibited that the electron mediator did amply the signal of SPS and the mediator existed on the surface of electrode was better than that existed in a solution. The electrodes constructed under the optimal conditions have 2 been used to develop a glucose SPS which showed a wide linear range from 0.1 mM to10 mM (R 2 =0.997) and a low detection limit of 23.7 μM (S/N=3). Therefore, the newly developed SPS was sensitive and facile for glucose detection, which could promise the possibility of its application in real samples.
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高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Baoyang Lu,Yao Lu,Yangping Wen,Xuemin Duan,Jingkun Xu,Shuai Chen,Long Zhang
A novel chiral L-alanine-modified 3,4-ethylenedioxythiophene (EDOT) precursor, (2S)-(2,3-dihydrothieno[3,4- b ][1,4]dioxin-2-yl)methyl 2-( tert -butoxy carbonylamino)propanoate (EDOT-Boc-Ala), was synthesized and electropolymerized in CH 2 Cl 2 –Bu 4 NBF. The corresponding polymer, poly((2S)-(2,3-dihydrothieno[3,4- b ][1,4]dioxin-2-yl)methyl 2-( tert -butoxy carbonylamino)propanoate) (PEDOT-Boc-Ala) film showed good redox activity and stability. The electrochemical behavior, structural characterization, chirality, solubility, spectroscopic properties, thermal stability, and morphology of PEDOT-Boc-Ala film were investigated. Both doped and dedoped PEDOT-Boc-Ala film could well dissolve in strong polar solvents such as dimethyl sulfoxide, tetrahydrofuran, and acetone, etc. The determination of specific rotation showed that the electropolymerization of EDOT-Boc-Ala did not influence its conformation and the polymer exhibited an enhanced specific rotation ([α] 20.0 = -191.08°) in comparison with that of the monomer ([α] 20.0 = -30.77°). Moreover, the amperometric biosensor based on PEDOT-Boc-Ala film (as immobilization matrix of biologically-active species) was successfully fabricated and employed to determine the concentration of vitamin C.
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高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Qing ZHOU,Ning Long,Lan LIU,Haiyun ZHAI,Mingfang ZHU
A highly selective molecularly imprinted polymer modified carbon paste electrode was developed. The Moxifloxacin Hydrochloride molecularly imprinted polymer was synthesized by thermal initiation precipitation polymerization, and the modified electrode was prepared by mixing graphite and polymer (90:10). Studied the electrochemical behavior and established the determination method of Moxifloxacin Hydrochloride at the electrode. The results showed that the sensor has high selectivity and sensitivity. and exhibited a linear voltammetric response for Moxifloxacin Hydrochloride in the concentration range of 3.13×10 -6 ~2.0×10 -4 mol•L -1 , with the limit of detection (LOD) of 5.9×10 -8 mol•L -1 (S/N=3). The sensor was applied to determine Moxifloxacin Hydrochloride in Avelox tablets and and human serum samples. The recoveries of Moxifloxacin Hydrochloride ranged from 97.2% to 104.5%.
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高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Dufen Hu,Baoyang Lu,Kaixin Zhang,Xiaoxia Sun,Jingkun Xu,Xuemin Duan,Liqi Dong,Hui Sun,Xiaofei Zhu,Shijie Zhen
Two amino-functionalized chiral poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives, poly( N -( tert -butoxycarbonyl)-L-phenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide) (PEDOT-Boc-Phe) and poly(L-phenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide) (PEDOT-Phe), were synthesized electrochemically via potentiostatic polymerization of corresponding monomers N -( tert -butoxycarbonyl)-L-phenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide (EDOT-Boc-Phe) and L-phenylalayl (3,4-ethylenedioxythiophene-2'-yl)methylamide (EDOT-Phe). The electrochemical behavior, structural characterization, spectroscopic properties, and surface morphology of two chiral conducting polymer films were systematically explored. They displayed excellent reversible redox activities, and rough and compact surface. Importantly, PEDOT-Boc-Phe and PEDOT-Phe modified electrodes were used to identify 3,4-dihydroxyphenylalanine (DOPA) enantiomers by square wave voltammetry (SWV) in sulphuric acid solution. It is interesting that the SWV peak currents of enantiomers were found to be quite different and hence the enantiomers could be successfully recognized but the enantioselectivity was not observed using the common method of cyclic voltammetry (CV). Satisfactory results implied that the obtained polymer films could play crucial roles in the development of practical value and analytical application prospects.
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高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2023
·
IF 16.5
Na Zhou,Jiazhi Wang,Ning Zhang,Zhi Wang,Hengguo Wang,Gang Huang,Di Bao,Haixia Zhong,Xinbo Zhang
Electrochemical conversion of nitrate (NO 3 − ) pollutants into chemical feedstock and fuel ammonia (NH 3 ) can contribute to sustainable mitigation of the current severe energy and environmental crises. However, the electrocatalytic NO 3 − reduction to NH 3 (NRA) involves a sluggish multielectron and proton transfer process that competes with the hydrogen evolution reaction (HER) in aqueous media, imposing great challenges in developing highly selective catalysts for NRA. In this study, we developed a copper and copper-tetracyanoquinodimethane composite catalyst (Cu@CuTCNQ), which possesses a high density of copper vacancy defects. This catalyst has been proven to be efficient for NRA through an in situ electrochemical reconstruction method. The structural evolution of CuTCNQ during NRA was investigated by in situ Raman spectroscopy, which indicated an accelerated charge transfer from the CuTCNQ substrate to the derived Cu, which facilitated the adsorption activation of NO 3 − . The obtained Cu@CuTCNQ exhibited an excellent catalytic performance for NRA, with a Faradaic efficiency of 96.4% and productivity of 144.8 μmol h −1 cm −2 at −0.6 V vs . a reversible hydrogen electrode, superior to Cu nanoparticle counterparts and most Cu-based catalysts. Cu vacancy defects and sufficient interfacial charge transfer synergistically optimize the charge distribution of Cu active sites, reduce the energy barrier for NO 3 − adsorption, and promote deoxidation and hydrogenation processes, thus enhancing NRA and selectivity.
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