Science China-Chemistry
·
2013
·Vol. 56
·期 5
·567-575
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IF 1.327
Xiang Ting,Zhang ZuLei,Liu HaiQing,Yin ZhengZhi,Li Lei,Liu XiaoMing
Nanofiber membranes from the composite of cellulose acetate/polyvinylpyrrolidone were prepared using electrospinning technique. After treated with water and alcoholic KOH to remove partially polyvinylpyrrolidone and deacetylate the cellulose acetate, the membranes were further functionalized with thiol groups using thioglycolic acid. Related materials were characterized using infrared and thermogravimetric analysis. And the results showed that the membranes were success of functionalisation. Then the nanofiber membranes were used in the sorption-desorption process. The effects of pH, contacting time and adsorption capacity of nanofiber membranes were studied against Cu(II), Cd(II) and Pb(II) ions. And the maximum adsorption capacities of Pb (II), Cu (II), and Cd (II) ions were estimated at 30.96, 19.63, 34.70 mg g −1 . Our results suggested that the adsorption behaviour of metal ions could be described using Langmuir model. Their adsorption kinetics was in agreement with the model of pseudo-second order, suggesting chemical adsorption as the rate-limiting step of the adsorption mechanism. The durability of the thiol-functionalized cellulose nanofiber membranes was also evaluated by repetitive adsorption-desorption.
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CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Jiancheng Wang,Zhaoliang Peng,Ying Chen,Weiren Bao,Liping Chang,Gang Feng
Cu-SSZ-13/cordierite monolithic catalyst was prepared by in situ hydrothermal synthesis method. The physicochemical properties of the as-prepared Cu-SSZ-13/cordierite were investigated by X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, N 2 -adsorption, inductively coupled plasma, X-ray photoelectron spectroscopy, and solid-state NMR techniques. The removal of nitrogen oxides (NO x ) from simulated diesel vehicle exhaust gas was performed using fixed-bed reactor. The effects of crystallization time and addition of HF during hydrothermal synthesis, reaction space velocity, and aging treatment of catalyst on the catalytic performances of NO x reduction reactions were investigated. The results indicate that the optimum crystallization time was 72 h. Highly crystalline structure of zeolite Cu-SSZ-13 was formed, in a close combination with a carrier, via one step hydrothermal process. Cu-SSZ-13/cordierite showed excellent DeNO x performance for selective catalytic reduction (SCR) and anti-aging properties in a simulated diesel exhaust gas under a high space velocity. At a high space velocity of 72,000 h −1 , the highest conversion and N 2 selectivity of 94% and 90%, respectively, were achieved. After the aging for 50 h at 720 °C, NO x reduction rate was still >80% in the temperature range of 350–550 °C. The larger height to diameter ratio of the same catalysts enhanced the NH 3 -SCR catalytic activity and broadened the active temperature window. The addition of HF increased the catalytic activity and anti-aging performance of the sample.
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THIN SOLID FILMS
·
2014
·
IF 1.867
Zhongshi Xu,Qi Kang,Tingting Cai,Tingting Huang,Ping Zhang,Dazhong Shen
In this work, the adsorption kinetics of 1,2-dichloroethane (DCE) on [Cu(C 24 H 22 N 4 O 3 )]·CH 2 Cl 2 metal-organic framework (Cu-MOF) film were monitored in real time by a quartz crystal microbalance technique. It is shown that the adsorption process follows closely the pseudo-second-order kinetic model. With increasing amount of DCE added, the adsorption rate constant decreases while the initial adsorption rate increases. More than half of DCE adsorbed on Cu-MOF film is reversible with respect to the concentration dilution in gas phase. The adsorption isotherms are fitted well by the Langmuir model. The pre-adsorbed N 2 at atmospheric pressure on Cu-MOF film reduces slightly the adsorption rate constant, equilibrium constant and capacity of DCE. The adsorption rates at vapor pressure of DCE are 1.2–1.8 times of those in the presence of N 2 at atmospheric pressure. With increasing film thickness, the adsorption rate constant and mass adsorbed per unit film mass decreased. For DCE adsorbed at its vapor pressure (25 °C) on Cu-MOF film with thickness of 0.251, 0.589 and 1.19 μm, the adsorption equilibrium constants are 716.5, 695.5 and 649.2 L/mol, and the saturation adsorption capacities are 6.537, 5.742 and 5.193 mmol/g, respectively. With increasing temperature, the adsorption rate constant increases, but the mass of DCE adsorbed on the adsorption equilibrium constant and capacity decreases.
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JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2015
·Vol. 91
·期 5
·1378-1386
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IF 2.349
Qiujin Jia,Dongping Li,Xuechuan Gao,Jilong Yan,Qinglin Ma,Fanjun Meng
BACKGROUND Although methyl acrylate has been graft polymerized from cellulose and functionalized with hydrazine and hydroxylamine for removal of copper and nickel ions, the adsorption capacity was less than 80 mg g −1 . The present work reported hydrazinolysis of cellulose-graft-polymethyl acrylate and remarkably improved adsorption capacity for Cu(II) and Ni(II) in aqueous solution. RESULTS Hydrazinolyzed cellulose-graft-polymethyl acrylate (Cell-g-PMA-HZ) has been prepared by ceric salt-initiated graft polymerization of methyl acrylate from microcrystalline cellulose surface and subsequent hydrazinolysis with hydrazine hydrate. The successful synthesis was confirmed by Fourier-transform infrared spectroscopy, 13 C-NMR, elemental analysis, scanning electron microscopy and thermogravimetric analysis. Adsorption behavior of Cell-g-PMA-HZ for Cu(II) and Ni(II) were studied through batch static adsorption processes and column chromatography methods. The influences of graft yield, initial pH, contact time and temperature on adsorption capacity of Cell-g-PMA-HZ as well as adsorption equilibrium, kinetic and thermodynamic properties were studied in detail. Kinetic adsorption can be explained by pseudo-second-order and adsorption isotherms fitted with Langmuir isotherm model, from which maximum equilibrium adsorption capacity can be derived as 229.36 mg g −1 for Cu(II) and 173.91mg g −1 for Ni(II) at 28°C. Further thermodynamic investigation indicated that adsorption of Cu(II) and Ni(II) by adsorbent Cell-g-PMA-HZ was exothermic and spontaneous under the studied conditions. CONCLUSIONS Hydrazinolysis of cellulose-graft-polymethyl acrylate has been accomplished. As an adsorbent, the prepared Cell-g-PMA-HZ was reusable and fairly efficient for removal of Cu(II) and Ni(II) from aqueous solution. © 2015 Society of Chemical Industry
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MATERIALS CHEMISTRY AND PHYSICS
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2014
·
IF 2.129
Mingyi Tang,Sai Zhang,Xianxian Li,Xiaobo Pang,Haixia Qiu
A facile and efficient approach to synthesize Fe 3 O 4 @Cu nanocomposites using l -Lysine as a linker was developed. The morphology, composition and crystallinity of the Fe 3 O 4 @Cu nanocomposites were characterized by Fourier Transform infrared spectroscopy , transmission electron microscopy , energy-dispersive X-ray spectroscopy, and powder X-ray diffraction. In addition, the magnetic properties were determined with vibrating sample magnetometer . The surface of the Fe 3 O 4 contained many small Cu nanoparticles with sizes of about 3 nm. It was found that the Fe 3 O 4 @Cu nanocomposites could catalyze the degradation of organic dyes. The catalytic activities of the Fe 3 O 4 @Cu nanocomposites for the reduction of nitrophenol were also studied. The Fe 3 O 4 @Cu nanocomposites are more efficient catalysts compared with Cu nanoparticles and can easily be recovered from the reaction mixture with magnet. The cost effective and recyclable Fe 3 O 4 @Cu nanocomposites provide an exciting new material for environmental protection applications.
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FOOD CHEMISTRY
·
2015
·
IF 3.391
Juying Hou,Guangjuan Dong,Zhengbin Tian,Jiutian Lu,Qianqian Wang,Shiyun Ai,Minglin Wang
In this paper, a simple and sensitive fluorescent sensor for dichlorvos was first constructed based on carbon dots-Cu(II) system. These carbon dots were obtained by simple hydrothermal reaction of feather. The fluorescence of these carbon dots can be selectively quenched by Cu 2+ ion. When acetylcholinesterase and acetylthiocholine were introduced into the system, thiocholine came into being, which can react with Cu 2+ ion and restore the fluorescence of the system. The reaction mechanism between Cu 2+ ion and thiocholine was confirmed by X-ray photoelectron spectroscopy. As one kind of acetylcholinesterase inhibitor, organophosphorus pesticides can be detected based on this sensing system. As an example of organophosphorus pesticides, dichlorvos was detected with a linear range of 6.0 × 10 −9 –6.0 × 10 −8 M. This sensing system has been successfully used for the analysis of cabbage and fruit juice samples.
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RSC Advances
·
2015
·Vol. 5
·期 117
·96372-96376
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IF 3.84
Zheng-Jun Wang,Peng-Hui Wang,Jing-Jing Lv,Jiu-Ju Feng,Xinhua Xu,Ai-Jun Wang,Chak-Tong Au,Renhua Qiu
Commercial copolymer Luviset clear (L1), an environmentally benign and efficient ligand, was used to facilitate the catalytic performance of Cu(NO3)2 for homo-coupling of terminal alkynes. A series of substituted aromatic and aliphatic terminal alkynes were investigated. It was found that Cu(NO3)2@L1 can catalyze the C–C coupling reactions without any other base, and the corresponding diynes are generated in good to excellent yield. X-ray photoelectron spectroscopy was used to study the reaction mechanism, and the results evidence a Cu(II)/Cu(I) catalytic system. Additionally, the catalyst can be easily separated and reused without showing significant loss of catalytic activity.
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RSC Advances
·
2015
·Vol. 5
·期 72
·58804-58812
·
IF 3.84
Ang Cao,Guilong Liu,Yizhi Yue,Lihong Zhang,Yuan Liu
A series of layered double hydroxides (LDHs) with different Cu/Co ratios were prepared according to the co-precipitation method and used as catalyst precursors for higher alcohol synthesis. The prepared samples were characterized by XRD, TPR, SEM, TEM and BET techniques. After calcination, the LDHs were transformed into a mixture of CuO, Co3O4, CuCo2O4 and alumina, and these oxides were mixed uniformly with sizes of several nanometers. For the sample with a ratio of Cu/Co = 1/2, the copper and cobalt species are mainly in the CuCo2O4 phase. In the reduction process, the superior mixed copper and cobalt species in nanoscale were reduced to Cu–Co alloy, which was confirmed by the XRD and TEM results. The prepared bimetallic catalysts showed high activity, good stability and very high selectivity to C2+ alcohols. With the best catalyst, CO conversion of 51.8%, selectivity to alcohols of 45.8% and 94.3 wt% of C2+OH in the total alcohols were obtained at 250 °C, 3 MPa and GHSV of 3900 mL (gcat h)−1.
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Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 45
·22708-22715
·
IF 7.443
Chunxiao Lv,Xianfeng Yang,Ahmad Umar,Yanzhi Xia,Yi(Alec) Jia,Lu Shang,Tierui Zhang,Dongjiang Yang
The increasing demand for high performance lithium ion batteries (LIBs) has aroused great interest in developing high specific capacity, cycle performance and rate capability anode materials. Transition metal oxides (TMOs) have attracted much attention as promising anode materials for rechargeable LIBs owing to their high theoretical capacity. Here, a general strategy has been developed to fabricate high-performance fibrous TMO anodes such as elemental Ni doped NiO fibre (NiO/Ni/C-F), yolk–shell structured carbon@Fe2O3 fibre (C@Fe2O3-F), and hollow CuO fibre (CuO-HF) with controllable nanostructures by using alginate microfibres as templates. The key to the formation of various TMO micro-/nano-structures is the templating ability of the natural structure of long alginate molecular chains, where the metal cations can be confined in an “egg-box” via coordination with negatively charged α-L-guluronate blocks. When tested as anode materials for LIB half cells, these fibrous electrodes deliver excellent cycling performance with no capacity decrease after 200 cycles (793 mA h g−1, NiO/Ni/C-F, 0.072 A g−1; 1035 mA h g−1, C@Fe2O3-F, 0.1 A g−1; 670 mA h g−1, CuO-HF, 0.067 A g−1), and demonstrate great rate performance at different current densities. This finding highlights a general, green and eco-friendly strategy for the scale-up production of potential high-performance TMO anodes for LIBs.
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JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2013
·
IF 2.145
Wei-guo Pan,Jie-nan Hong,Rui-tang Guo,Wen-long Zhen,Hong-lei Ding,Qiang Jin,Cheng-gang Ding,Shi-yi Guo
MnO x –CuO x /TiO 2 and MnO x –CuO x /Al 2 O 3 catalysts were prepared by sol–gel method and used for low temperature selective catalytic reduction of NO with NH 3 . The results showed that MnO x –CuO x /TiO 2 had better catalytic activity and SO 2 resistance than MnO x –CuO x /Al 2 O 3 in the temperature range of 100–250 °C. The properties of the catalysts were characterized by using XRD, N 2 adsorption, temperature programmed reduction (H 2 -TPR) and temperature programmed desorption (NH 3 -TPD). It was found that the support has a great impact on the acidity of catalyst; TiO 2 and Al 2 O 3 can promote the formation of Lewis acid sites and Brönsted acid sites respectively.
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Journal of Materials Chemistry C
·
2015
·Vol. 3
·期 39
·10114-10120
·
IF 4.696
Zhenyang Liu,Aiwei Tang,Miao Wang,Chunhe Yang,Feng Teng
A simple heating-up colloidal approach has been developed to synthesize quaternary Cu–In–Zn–S (CIZS) nanocystals with different emission colors, which can be tuned by varying the Cu : In : Zn precursor ratios. The as-obtained products have a quasi-triangular shape with a small size distribution, and their crystal phase can be varied from cubic zinc-blende to hexagonal wurtzite structure with an increase of Cu stoichiometry. The inductively coupled plasma optical emission spectrometry (ICP-OES) results reveal that the as-obtained CIZS nanocrystals are Cu-deficient, and the Cu-vacancies have a significant effect on their optical properties. Moreover, the photoluminescence (PL) spectra of the CIZS nanocrystals recorded at different growth periods indicate that the partial cation exchange of Cu+ and In3+ with Zn2+ takes charge of the growth process. After coating a ZnS shell over the CIZS nanocrystals, the PL quantum yield (PLQY) is improved greatly and a blue-shift of the PL peak is observed as compared to that of plain CIZS nanocrystals. More interestingly, the highly luminescent CIZS/ZnS core/shell nanocrystals with different colors have been incorporated into poly(dimethylsiloxane) (PDMS) to be fabricated on an engraved “BJTU” glass substrate, and the as-obtained PDMS membranes exhibit a bright emission under UV light, which also show good stability when they are bent arbitrarily or immersed in water. This heating-up method has also been extended to the preparation of five-component Cu–Ag–In–Zn–S and Cu–Mn–In–Zn–S nanocrystals, which possess a cubic zinc-blende crystal structure and have bright luminescence. Our work may shed light on the synthesis of multi-component semiconductor nanocrystals.
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ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Yunsu Ma,Yao Cen,Muhammad Sohail,Guanhong Xu,Fangdi Wei,Menglan Shi,Xiaoman Xu,Yueyue Song,Yujie Ma,Qin Hu
In this work, a new kind of N, Cu codoped carbon dots (N/Cu-CDs) was prepared via a facile one-pot hydrothermal method by using citric acid monohydrate, copper acetate monohydrate and diethylenetriamine. The prepared N/Cu-CDs with a high quantum yield (50.1%) showed excitation-independent emission at 460 nm. The structure and fluorescence properties of N/Cu-CDs were characterized by high-resolution transmission electron microscopy, fluorescence spectrofluorometer, FT-IR spectrometer, UV–visible spectrophotometer and X-ray photoelectron spectroscopy. N/Cu-CDs were applied to establishing a ratiometric fluorescence probe toward H2O2 based on the inner filter effect (IFE) between N/Cu-CDs and DAP (2,3-diaminophenazine, the oxidative product of o-phenylenediamine (OPD)), and provided a ratiometric fluorescence universal platform for detection of the metabolites participating in H2O2-generation reactions (cholesterol and xanthine). The proposed method was demonstrated to be ultrasensitive and highly selective for cholesterol and xanthine assay with detection limits of 0.03 and 0.10 μM, respectively. The fluorescence probe built was applied to the determination of cholesterol and xanthine in human serum with satisfactory results.
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