ACS Omega
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2019
·
IF 2.584
Wei Sun,Qi Sun,Qiang Zhao,Luminita Marin,Xinjian Cheng
In this work, SiO2 microspheres were first prepared by a conventional Stöber method and then etched by NaOH solution to obtain porous ones. By tuning the degree of etching, specific surface area of SiO2 microspheres could be controlled. Then, small fluorescent molecules are synthesized and incorporated onto the surface and/or pores of the SiO2 via layer-by-layer reaction to obtain fluorescent microspheres, namely, SiO2–NH2–BODIPY (SiNBB), SiO2–NH2–BODIPY–indole–benzothiazole (SiNBIT), and SiO2–NH2–BODIPY–indole–benzoxazole (SiNBIO). The as-prepared microspheres SiNBB exhibit highly sensitive and selective recognition ability for Hg2+ and Pb2+. When SiNBB encounters Hg2+ and Pb2+, the fluorescence intensity of SiNBB is increased up to fivefold. SiNBIT and SiNBIO are solely sensitive to Hg2+, and both have a single high sensitivity to recognize Hg2+. The adsorption efficiency of Hg2+ by the three fluorescent microspheres SiNBB, SiNBIT, and SiNBIO reached 2.91, 0.99, and 0.98 g/g of microspheres, respectively. Experimental results of A549 cells and zebrafish indicate that the fluorescent microspheres are permeable to cell membranes and organisms. The distribution of Hg2+ in the brain of zebrafish was obtained by the fluorescence confocal imaging technique, and Hg2+ was successfully detected in A549 cells and zebrafish.
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PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2019
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IF 2.931
Shengmei Song,Fan Liang,Minglu Li,Fangfang Du,Wenjuan Dong,Xiaojuan Gong,Shaomin Shuang,Chuan Dong
A fluorescent sulfur and nitrogen dual-doped carbon dots (S,N-CDs) was prepared by a simple and one-step acid-base neutralization and exothermic carbonization method. Hexavalent chromium (Cr(VI)) could effectively quench the fluorescence of S,N-CDs based on inner filter effect (IFE) and dynamic quenching, whereas ascorbic acid (AA) could recover the fluorescence of S,N-CDs/Cr(VI) because of IFE weakening. So an “on-off-on” and label-free nano-probe consecutive determination of Cr(VI) and AA was constructed. This nano-probe system demonstrated excellent selectivity and sensitivity to Cr(VI) and AA with linear range of 0.065–198 μmol/L (3.38–10,296 μg/L) and 6.6–892 μmol/L (1.16–157 mg/L), respectively. Meanwhile, the as-prepared S,N-CDs possess low toxicity and could be used for multi-color cell imaging in SMMC 7721 cells. More importantly, this nano-probe was successfully employed for detection of Cr(VI) in tap water and AA in food samples. In view of its simple detection condition, rapid response, wide linear range, low detection limit and inexpensive instrument, the as-constructed nano-probe system could have a wide range of potential application, including water quality monitoring and evaluation, food inspection and testing and biomedical analysis.
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PubMed
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
Haibin Li,Li Ma,Liya Zhou,Jing Gao,Zhihong Huang,Ying He,Yanjun Jiang
The combination of metal nanoparticle-catalysts and biocatalysts to perform cascade catalytic strategy is a powerful platform for synthesis or degradation of complex molecules. In this work, an integrated nanoreactor (INR) was successfully prepared via immobilizing organophosphorus hydrolase (OPH) onto porous carbon materials containing Co nanoparticles (C/Co). The C/Co was synthesized conveniently by pyrolysis of a metal-organic framework (MOF) named ZIF-67. This INR can reduce the toxicity of organophosphate nerve agent up to 208-fold by cascade degradation route. In this INR, C/Co not only acts as chemocatalyst but also serves as support for OPH, which allows an easy separation and reuse due to its magnetic properties. Moreover, this INR shows outstanding universal applicability, reusability and stability. With this proof-of-concept, it is foreseeable that the future metal nanoparticles that formed by pyrolyzing MOF will combine more other biocatalysts for perspective applications in more fields.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 11
·8216-8225
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IF 3.442
Xu Wen,Cao Bo,Lin Hechun,Cheng Wenjuan,Luo Chunhua,Peng Hui,Duan Chungang
The catalytic activities of three topotactic phase strontium cobaltites (SCO, hexagonal, orthorhombic and tetragonal) for H 2 O 2 decomposition were studied. All they present excellent catalytic activity with good stability at cycled test, and the mesoporous tetragonal SCO exhibits the best activity. Detailed kinetic research indicates the zero-order process of H 2 O 2 decomposition. Increasing the temperature will accelerate the reactions greatly with the controlled temperature in the range of 20–45 °C. The calculated active energy ( E a ) for H-SCO, O-SCO and T-SCO is 93.2, 85.1 and 87.5 (kJ/mol), respectively. The efficient catalytic degradation of Rhodamine B illustrates that SCO is a kind of promising catalysis for the advanced oxidation process.
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高影响因子
TALANTA
·
2019
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IF 4.916
Shuyan Ge,Jingbo He,Chenxing Ma,Jiyang Liu,Fengna Xi,Xiaoping Dong
Heteroatom doping can endow graphene quantum dots (GQDs) with various new or improved structural, optical and physicochemical properties. In contrast to the widely reported oxygen, nitrogen or sulfur doping in GQDs, simple and scalable synthesis of boron-doped GQDs (B-GQDs) with high yield and quantum yields remains challenge. In this work, B-GQDs are one-step synthesized and serve as the fluorescence probes for the fabrication of sensors towards Fe 3+ ion or phosphate (Pi) as well as biosensor towards cytochrome C (Cyt C). The B-GQDs are facile synthesized using one-step bottom-up molecular fusion between 1,3,6-trinitropyrene and borax in sodium hydroxide under hydrothermal process. The synthesis can be performed using large volume autoclave (500 ml) with a high yield of 71%, indicating possibility for gram-scale production of B-GQDs. The as-prepared B-GQDs exhibit single or bilayer graphene structure, high crystallinity , uniform size, bright (absolute photoluminescence quantum yield of 16.8%) and excitation-independent green fluorescence (maximum excitation wavelength and emission wavelength of 480 nm and 520 nm, respectively). Successful doping of B atoms in the lattice of GQDs enables high selectivity towards Fe 3+ . Based on quenching of fluorescence of B-GQDs by Fe 3+ (turn-off model), detection of Fe 3+ (with limit of detection-LOD of 31.2 nM) and Fe 3+ -rich Cyt C (with LOD of 5.9 μg/ml) are demonstrated. As Pi can recover Fe 3+ -quenched fluorescence of B-GQDs (turn-off-on model), indirect fluorescent detection of Pi is also achieved with LOD of 340 nM. In addition, detection of Fe 3+ , Cyt C and Pi in real samples is achieved.
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PubMed
高影响因子
SOLID STATE SCIENCES
·
2019
·
IF 2.155
Jianxun Zhao,Xiangjun Zhou,Yalan Guo,Zhongmin Su,Heng Liu,Wanqiang Liu,Shang Gao
Co 0.9 Cu 0.1 Si alloy was fabricated via mechanical alloying technique. Different amount of palladium was doped into the Co 0.9 Cu 0.1 Si alloy by ball milling. The composite alloy combined the excellent electrocatalysis activity of Pd, exhibiting preferable electrochemical performance than the original alloy. The Co 0.9 Cu 0.1 Si + 5 wt% Pd composite showed a C max of 559.2 mAh/g, significantly higher than that for Co 0.9 Cu 0.1 Si (502.1 mAh/g). The cycle stability was also enhanced after Pd loading. Moreover, the effect of ball milling time on electrochemical performance for the composite alloy was also investigated. 5 wt% Pd was mixed with the Co 0.9 Cu 0.1 Si alloy at different ball milling time (0.5 h, 1 h, 2 h, 3 h and 5 h). The optimal discharge capacity, capacity retention and high-rate dischargeability were obtained under the ball milling time of 2 h. The studies on electrochemical reaction kinetics demonstrated that the addition of Pd could accelerate the charge-transfer, thus enhancing the electrochemical activity and reaction kinetics of the alloy. The results indicated that Pd loading was an effective way in enhancing the electrochemical performance of Co 0.9 Cu 0.1 Si alloy.
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CHEMICAL PAPERS
·
2019
·Vol. 74
·期 2
·485-497
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IF 1.246
Quan Cong,Liu Jiayu,Sun Wei,Cheng Xinjian
It is extremely necessary to detect heavy metals sensitively and selectively, especially the ions that will cause great harm to humans and the environment. This work deals with two fluorescent chemosensors and their outstanding role when detecting Zn 2+ and Cd 2+ ions. First, a small molecular chemosensor (TPB) has been designed and synthesized via Suzuki reaction using one part of benzene-1,3,5-triyltriboronic acid and three parts of 2-bromo-1, 10-phenanthroline as starting materials. And then, its corresponding macromolecular fluorescent chemosensor (PTPB) was synthesized. The infrared spectra, mass spectrometry (MS), and 1 H-NMR were used to study the structures of TPB and PTPB. From what has been studied, the TPB and PTPB were stable in a relative wide pH range. As soon as the Cd 2+ and Zn 2+ ions added, fluorescence of the two sensors TPB and PTPB was changed obviously. In addition, PTPB was found have better performance to both Cd 2+ and Zn 2+ than TPB through the ‘‘molecular wire’’ mechanism. Job’s plots were also be tested, showing that the combination ratio of TPB and PTPB to Cd 2+ and Zn 2+ were both 3:1 (ion/sensor). In addition, the minimum detection limits of the macromolecular chemosensor PTPB for Cd 2+ and Zn 2+ reached 0.424 μM and 1.27 μM, respectively.
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高影响因子
ACS Applied Nano Materials
·
2019
·
IF 0
Sefiu Abolaji Rasaki,Hangjia Shen,Tiju Thomas,Minghui Yang
Transition metal carbides have received significant attention for oxygen reduction reaction (ORR) applications primarily owing to their good conductivity. However, cobalt carbide based catalysts (CoCx) are difficult to prepare, owing to the preferential formation of metallic cobalt and cobalt oxide instead. Also, cobalt carbide nanoparticles rapidly coarsen and undergo grain growth. This is a problem as it results in low current density and poor active site exposures. In this study, carbon-supported CoCx (C@CoCx) is successfully synthesized using the solid–solid separation synthesis method. The limitations identified to be associated with cobalt carbide nanoparticle based electrocatalysts are overcome. Here, the synthetic approach ensures good distribution and protection of CoCx on in situ generated carbon nanotubes. This results in robust activities with an appreciable onset potential of ∼0.92 V, a half-wave potential of ∼0.8 V, and a durability of ∼100% (tested on ∼22 h continuous operation runs). In alkaline medium, C@CoCx compares favorably with commercial platinum dispersed on carbon (20 wt % Pt/C) and shows a higher current density of ∼300 μA/cm2 at an electrode potential of 0.6 V. All of these indicate that there is a synergistic charge transfer between CoCx and an in situ generated carbon nanotube. This is due to intimate contact that exists between the two phases; it is in fact responsible for superior methanol tolerance observed, making it a good candidate for direct methanol fuel cells.
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SOLID STATE COMMUNICATIONS
·
2019
·
IF 1.433
Junpu Wang,Duanwei He,Xin Li,Jiawei Zhang,Qiang Li,Zhiwei Wang,Yuzhu Su,Yi Tian,Jing Yang,Bo Peng
The new melting curve of cobalt (Co) was determined to be 12 GPa using the in situ high-pressure temperature measurement method (HPTM) in a high-volume cubic press using two melting criteria: first, plateaus in the temperature vs power functions in situ experiments, and second, the texture changes in the samples before and after high-pressure high-temperature (HP-HT) treatments with a scanning electron microscope (SEM). The slope of the melting point with increasing pressure was approximately 33 K/GPa in our experimental pressure range and progressively decreased under further compression. Our new melting curve of Co under high pressure is reasonably consistent with the simulation results using one-phase and two-phase calculations and has a similar trend with the reported melting curves of Fe and Ni.
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ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Gang Wen,Hui Liu,Tao Liang,Yunpeng Ouyang,Liang Tan,Renzong Hu,Jun Liu,Yao Zhang,Min Zhu
Despite there being many reports on SnO 2 -based anode materials, most of the electrode materials are tested in half cells using lithium metal with unlimited lithium-ion sources as the counter electrode, which may conceal the real properties of these composites to a certain extent. In this study, a ternary SnO 2 –Co–C composite was fabricated by a scalable ball milling strategy. The composite exhibited high initial Coulombic efficiency (ICE, >80%), a large capacity (∼900 mA h g −1 ) and superior cycling stability (capacity retention more than 99% after 100 cycles) in half cells. Furthermore, coin-type full cells in which the ternary SnO 2 –Co–C anodes were paired with different cathodes were demonstrated. A LiFePO 4 ||SnO 2 –Co–C full cell tested at 0.5–3.4 V exhibited an ICE of 75.1% and an initial discharge capacity of 906 mA h g −1 , which were close to those of the SnO 2 –Co–C||Li half cells. By analyzing the cycling performance and characteristics of the charge/discharge process for the full cells with different capacity ratios of cathode/anode, it was confirmed that the capacity decay of the full cells was due to the continuous consumption of Li + ions during cycling. Hence, the testing voltage windows were adjusted according to the lithiation/de-lithiation behavior of the SnO 2 . On this basis, the LiFePO 4 ||SnO 2 –Co–C full cells tested at 2.3–3.4 V and the LiCoO 2 ||SnO 2 –Co–C full cells tested at 2.60–3.75 V exhibited excellent cycling stability, demonstrating 80.3% and almost 100% capacity retention after 100 cycles, respectively, thereby laying a foundation for the practical application of advanced SnO 2 -based anodes in lithium-ion batteries.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Jianxun Zhao,Xiaojie Zhai,Xing Tao,Heng Liu,Wanqiang Liu,Dayong Jiang,Shang Gao
Mechanical alloying technique was used to prepare the Co 0.9 Cu 0.1 Si alloy. Composite materials of Co 0.9 Cu 0.1 Si doping with different amounts of multi-walled carbon nanotubes (MWCNTs) or lithium modified MWCNTs (Li-MWCNTs) were obtained via ball-milling to improve the hydrogen storage performance of Co 0.9 Cu 0.1 Si. XRD , SEM and TEM were used to analysis the structural properties of the samples. A three-electrode battery system was carried out to test the electrochemical properties . After the addition of MWCNTs, the composites showed higher discharge capacity, stronger HRD, better cyclic stability and lower charge-transfer resistance than the original Co 0.9 Cu 0.1 Si alloy. The electro-catalytic function of MWCNTs, the reduction of particle size and the raise of specific surface area for Co 0.9 Cu 0.1 Si alloy may provide larger electrochemically accessible area and rapid channel for hydrogen transportation , which are important to enhance the electrochemical performance of the alloy. Moreover, a further improvement was achieved after the addition of Li-MWCNTs, illustrating that the MWCNTs and lithium species had synergistic effects in improving the discharge capacity and reaction kinetics of the Co 0.9 Cu 0.1 Si alloy electrode. As the weight ratio of the alloy and Li-MWCNTs was 15:1, the optimal discharge capacity of 624.4 mAh/g and the highest capacity retention of 67.5% were achieved.
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高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2018
·
IF 3.046
Xiaoshan Yang,Xiufang Cui,Guo Jin,Jinna Liu,Yanbo Chen,Zhe Liu
Laser additive manufacturing (LAM) is a novel method for processing compositionally graded alloys and becomes increasingly important in the context of next-generation manufacturing technology. In this work, (Fe 60 Co 35 Ni 5 ) 78 Si 6 B 12 Cu 1 Mo 3 soft magnetic alloys with different laser power were designed and processed by the LAM. The magnitudes of magnetic properties were analyzed, and the relationships among composition-microstructure-magnetic properties assessed. Results show that the (Fe 60 Co 35 Ni 5 ) 78 Si 6 B 12 Cu 1 Mo 3 alloys by LAM exhibits relative uniform microstructure and comparable magnetic property compared with those conventional processed alloys. The bcc dominated microstructures exhibit a substantially higher saturation magnetization (Ms). With the increase in power, the average grain size of the alloy increased slightly and the increasing volume fraction of the Fe Si phase leaded to the enhancement of magnetization. The (Fe 60 Co 35 Ni 5 ) 78 Si 6 B 12 Cu 1 Mo 3 alloys with laser power of 3000 W exhibits the highest Ms (199 emu/g). The appearance of Fe 3 B results in coarse dendrites and high coercivity (Hc) in the multiple re-heating cycles.
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高影响因子
危险品化学品经营许可证（带存储）