ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Wei Zhang,Wei Liu,Ping Li,Fang Huang,Hui Wang,Bo Tang
Hydrogen peroxide (H2O2) as a reactive oxygen species (ROS) plays a crucial role in oxidative stress and signal transduction of organisms. Currently, a fluorescence probe has proven to be a powerful tool for the H2O2 analysis. However, the common problem is the slow response, causing difficulty in tracking H2O2 in situ. Herein, we describe a novel aggregation-induced emission (AIE) fluorescence probe based on increased polarity of C–B bonds that is well suited for monitoring H2O2 rapidly and selectively. Importantly, the probe was successfully applied to visualize H2O2 levels in living cells, which provides a rapid-response and highly selective fluorescence tool for monitoring of the H2O2 levels in biological process.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2014
·
IF 4.086
Mingjia Han,Muwu Li,Xin Wu,Jianhuang Zeng,Shijun Liao
Motivated by addressing the support corrosion or stability issue for electro-catalysts, a carbon composite support has been prepared by wet-impregnation of nano-sized TiO 2 and cobalt (II) acetate tetrahydrate together with XC-72 carbon black, followed by thermal treatment at 900 °C in a reductive atmosphere. Decomposition of cobalt acetate under thermal treatment yields TiO 2 -Co 3 O 4 -C composite support (CS), as is confirmed by X-ray diffraction analysis. The composite support is found to be more corrosion resistant and stable in acidic solution than that of the conventionally used carbon black, as is witnessed by the chronoamperometric response. This composite support is then used to load 40.3 wt.% Pt nanoparticles (Pt/CS) as an electro-catalyst for proton exchange membrane fuel cells. It is found that 27.9% of the electrochemical surface area (ECSA) retained in an accelerated stability test (AST) in 0.5 M H 2 SO 4 for Pt/CS, compared with 8.4% for 39.5 wt.% Pt catalyst supported on XC-72 carbon black. The TEM image after AST for Pt/CS also confirms its improved resistance to agglomeration. The Pt/CS catalyst shows higher mass-normalized activity for methanol oxidation in 0.5 M CH 3 OH + 0.5 M H 2 SO 4 and a slower activity decay relative to that of the benchmarked Pt catalyst on carbon.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
·
2015
·Vol. 117
·期 24
·
IF 2.183
Yang Yimin,Du Deyang,Kong Fan,Fan Jiyang,Qiu Teng
Indium-tin-oxide (ITO) nanoparticles were annealed in vacuum or reducing atmosphere to obtain different surface structures and investigate their influence on the adsorptive character and conformation of cytochrome c (Cyt c ) molecule. Annealing-induced morphometric or structural changes of ITO nanoparticles were characterized by instruments of transmission electron microscopy, x-ray diffraction, and Raman scattering. Semiconductor ITO nanoparticle-enhanced Raman scattering of Cyt c was observed and the enhanced efficiency was found to closely depend on the surface structures which control the adsorbance of buffer anions needed for Cyt c loading. Direct electron transfer between Cyt c and ITO surface at the moment of molecular elastic collision was found and a reverse electron transfer process for O-terminated surface and metal-terminated surface was observed, according to absorption spectroscopic measurement on the residual solution.
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2014
·Vol. 4
·期 5
·1286-1292
·
IF 4.76
Bing Liu,Ting Huang,Zehui Zhang,Zheng Wang,Yuhua Zhang,Jinlin Li
The present study reported the results on the water–gas shift (WGS) reaction over a series of Ru/C catalysts. It was found that the reduction method showed a remarkable effect on the catalytic activity of Ru/C catalysts over WGS reaction, which increased in an order of the reduction by NaBH4, ethylene glycol, H2. It has been shown that alkali additives with K2CO3 significantly improved the activity of the Ru/C catalysts. XPS results indicated that Ru species were further oxidized by the addition of K2CO3, which indicated an electron transfer from the alkali metal to the substrate, resulting in stronger bonding of the adsorbed gas. FTIR results showed that the absorption peak intensity of H2O and hydroxyl group increased with the increase of K2CO3 content, due to the strong hygroscopic ability of K2CO3. Through the addition of K2CO3 to the Ru/C catalyst, much more water was adsorbed around the catalytic active sites, reducing the strong adsorption of CO on the active sites. Thus the addition of K2CO3 balanced the concentration of water and CO on the active sites, which was considered to be the key step for low temperature WGS reaction over Ru supported on irreducible activated carbon.
✓ 已验证
产品关联
DOI
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2014
·Vol. 12
·期 18
·2969-2978
·
IF 3.487
Jiajun Zhang,Pinhua Li,Lei Wang
A novel KOAc-promoted α-position C–H activation and alkynylation of ethers with alkynyl bromides to 2-alkynyl ethers has been developed under transition-metal-free and simple reaction conditions. In addition, this methodology can also be extended to the vinylation of ethers with vinyl bromides in excellent regio- and stereo-selectivity. A wide range of direct C(sp)–C(sp3) and C(sp2)–C(sp3) bonds has been formed through this protocol, which offers a new and alternative route.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2015
·
IF 4.321
Lei Yue,Guangqian Li,Guijin He,Yongsheng Guo,Li Xu,Wenjun Fang
The precise investigations on modeling properties and performance of practical fuels are usually complicated because of the multi-component nature. On the basis of hydrogen to carbon ratio (H/C), as a simple and overall characterization parameter for hydrocarbon fuels, this work provides a comprehensive insight into the study of kerosene-based hydrocarbon fuels (H/C = 1.6–2.3). The fundamental properties and supercritical cracking performance of hydrocarbon fuels are influenced intrinsically by their H/C values and molecular weights ( M ) due to the compositional and structural effects. Thus, a new combined parameter, (H/C)/ M a , is proposed to model the performance of hydrocarbon fuels. It is found that the hydrocarbon fuel with a higher H/C has a higher net heating value, and that with a higher (H/C)/ M 0.1 has a lower density. The viscosity decreases with the increase of (H/C)/ M 0.5 . The flash point shows a decreasing trend against the increase of (H/C)/ M 2 . The densities, viscosities and net heating values of 23 hydrocarbon fuels are calculated by means of the regression equations with the H/C and M data, and they are in agreement with the corresponding experimental values with the relative errors less than 2.5%, 10% and 1.5%, respectively. As investigated in an electrically heated tube reactor, the hydrocarbon fuel with a higher H/C performs thermal cracking more easily, absorb more heat and form fewer cokes. As a result, the cracking performance of hydrocarbon fuels can be predicted reasonably to a certain extent on the basis of H/C values.
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2013
·Vol. 5
·期 16
·7564-7571
·
IF 6.233
Jie Sun,Haimei Liu,Xu Chen,David G. Evans,Wensheng Yang
Superposed cobalt(II)–cobalt(III) layered double hydroxide (CoII–CoIII-LDH) nanoplates were synthesized by an oil droplet template method, in which the main steps are as follows: LDH nanosheets were first assembled on an oil droplet template to form a multishell sphere, and then the oil droplet was easily removed under centrifugal force due to its very different density from that of the assembled LDH shell. This resulted in the multishell spheres being split open to create superposed LDH nanoplates. The resulting material has a three-stage architecture, namely, the primary building blocks of nanosheets, the secondary architecture of shells derived from the nanosheets, and the long-range architecture of superposed nanoplates assembled from the vertically stacked shells. Most importantly, the as-fabricated LDH-based hierarchical structure can be readily converted to a Co3O4/C composite via calcination, without obvious structural alteration, where the residual surfactant is the source of the carbon. When used as an anode material for Li-ion batteries, the Co3O4/C electrode exhibits an excellent electrochemical performance, which is attributed to the unique hierarchically porous structure.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2013
·
IF 4.675
Yuan Wang,Haibo Rong,Benzhen Li,Lidan Xing,Xiaoping Li,Weishan Li
Ultrafine Li 4 Ti 5 O 12 /C composite is synthesized by microemulsion with oleic acid as carbon precursor and particle size controller. The as-prepared sample is characterized with X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM), thermogravimetry analysis (TGA) and nitrogen absorption–desorption isotherms, and its performance as anode of lithium ion battery is determined with charge–discharge test and electrochemical impedance spectroscopy (EIS). The characterizations show that the as-prepared sample is composed of ultrafine Li 4 Ti 5 O 12 particles with average size of 25 nm, which are uniformly dispersed in carbon matrix with a carbon content as low as 2.69 wt%. Charge–discharge test indicates that the as-prepared sample exhibits excellent rate performance and cycling stability. At 10C, the highest discharge capacity reaches 136.3 mAh g −1 and the capacity retention is 96.4% after 100 cycles. The improved performance of the Li 4 Ti 5 O 12 /C composite is attributed to the ultrafine particle size and the uniform composite of Li 4 Ti 5 O 12 with carbon.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2015
·
IF 3.313
Hansheng Wan,Qizhi Dong,Guiming Zhu,Gang Yu,Tianwu Yin,Meiling Huang
In this work, anatase-TiO 2 is investigated as a catalyst support in Pd/TiO 2 –C composite to improve the electrocatalytic properties of Pd for formic acid oxidation reaction (FAOR). Pd/TiO 2 has been synthesized by an impregnation-reduction method and then mixed with Vulcan XC-72R carbon black to obtain Pd/TiO 2 –C composite. Transmission electron microscopy (TEM) images show Pd nanoparticles (ca.3.5 nm in average diameter) in the Pd/TiO 2 –C (1:1) composite catalyst were dispersed on the surface of TiO 2 with a narrow particle size distribution . Electrochemical tests demonstrate Pd/TiO 2 –C (1:1) composite has significantly increased catalytic activity and stability compared with Pd/C for FAOR. The proposed reasons for these observations are the excellent acid corrosion and oxidation resistance of TiO 2 and the synergistic effect of Pd and TiO 2 nanoparticles . The effect of mass ratios of TiO 2 to C on the catalytic performance is also discussed. The best catalytic activity and stability for FAOR is found when the mass ratio of TiO 2 to C is 1:1. It can be interpreted as the synergistic effects and conductivity reach balance at this point.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Xing Xu,Yunlong Xu,Huang Zhang,Mandi Ji,Hui Dong
The NiO doped LiFePO 4 /C composite was synthesized by a simple solid state method. The structure and morphology of synthesized particles were characterized by XRD, Raman spectrum , SEM, TEM and EDS. Electrochemical performance of the pristine and nickel oxide modified samples was evaluated by galvanostatic charge-discharge test, CV , and EIS . The results indicate that NiO doped LiFePO 4 /Li type coin cell exhibits improved specific capacity and cycle stability, especially at high rates. Among all the modified samples, the 5.0%wt NiO doped sample shows the best electrochemical performance, which achieves a specific capacity of 129 mA h g −1 at 1 C current rate due to the modest graphitization of carbon layer on the surface of LiFePO 4 particles. The results indicate that nickel oxide modification is an effective way to improve the electrochemical performance of LiFePO 4 /C cathode materials for lithium ion batteries .
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2016
·Vol. 92
·期 7
·1601-1612
·
IF 2.738
Jiahua Lu,Qing Liu,Zhongduo Xiong,Zhijun Xu,Yingjie Cai,Qiang Wang
BACKGROUND Synthetic dyes are present in the wastewater from many industrial processes and they cause serious problems to human and aquatic life. The development of a novel and effective peroxymonosulfate (PMS) activator is proposed to eliminate dyes pollution. A new magnetic nanocomposite, Fe 3 O 4 @C/MnCo 2 O 4 , was prepared and characterized. The activity of Fe 3 O 4 @C/MnCo 2 O 4 as heterogeneous catalyst for PMS activation was evaluated by the decolorization of Acid Orange II (AO II). RESULTS With a ‘Fe 3 O 4 @C/MnCo 2 O 4 + PMS’ system, the dye solution could be nearly completely decolorized in about 25 min over a wide pH range (pH 4.1−8.1), and 98% removal could be achieved in 15 min without pH adjustment (pH = 6.38). The influence of solution pH, dosage of catalyst and PMS, reaction temperature, and PMS activation mechanism were studied. It was found that sulfate radicals were the primary species responsible for the oxidation of AO II. The catalyst was magnetically separable and displayed good stability and reusability, giving six cycles of use without deterioration in its performance. CONCLUSION This study demonstrated the simple recycling and high activity of Fe 3 O 4 @C/MnCo 2 O 4 composite in PMS activation for the decolorization of AO II solution. It provides a promising way for the decontamination of organic pollutants. © 2016 Society of Chemical Industry
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 18
·12954-12965
·
IF 3.9
Thi Viet Ha Luu,Hong Yen Xuan Nguyen,Quoc Thang Nguyen,Quang Bac Nguyen,Thi Ha Chi Nguyen,Ngoc Chuc Pham,Xuan Dung Nguyen,Trung Kien Nguyen,Ngoc Nhiem Dao
This study attempted to improve the photocatalytic activity of zinc oxide (ZnO) semiconductors in the visible light region by introducing the co-doping of carbon (C) and tantalum (Ta) to ZnO (ZTC) using a simple hydrothermal method with the respective precursors. The obtained uniform ZTC nanoparticles with an average crystal size of 29.30 nm (according to Scherrer's equation) revealed a redshift with a decrease in bandgap (Eg) from 3.04 eV to 2.88 eV, allowing the obtained photocatalyst to absorb the energy of the visible light for photocatalysis. Furthermore, the Zn 2p and Ta 4f core level spectra confirmed the presence of Zn2+ and Ta5+ in the ZTC sample. In addition, the infrared spectra identified hydrogen-related defects (HRDs), while the O 1s spectra indicated the existence of oxygen vacancies (VO). Electrochemical tests revealed improvement in the electron conductivity and charge separation of the obtained materials. To follow, the photocatalytic performance assessment was conducted by varying the C/Zn2+ ratios (5, 10, and 15 mol%) in ZTC samples, the initial RhB concentration (7, 15, and 30 ppm), and the pH of the RhB solution (3.0–10.0). The photodegradation on ZTC samples showed the most effectiveness for a 7 ppm RhB solution with a C/Zn2+ ratio of 10 mol% in the slightly alkaline medium (pH 9.0). Additionally, ZTC also exhibited commendable durability after being reused several times. The nature of RhB photodegradation was proposed and discussed via a mechanism at the end of this work.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）