COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2014
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IF 2.354
Tianqi Li,Haihui Zhou,Jiaqi Huang,Junli Yin,Zhongxue Chen,Dan Liu,Ningshuang Zhang,Yafei Kuang
Pd–Au bimetallic nanoparticles were facilely prepared on Ni foil substrate via in-situ self-assembly in reverse microemulsion of water/Triton X-100/n-hexanol/n-hexane. The Pd–Au nanomaterials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). A homogeneous alloy structure of Pd–Au in the bimetallic nanoparticles is indicated by XRD analysis and TEM. The SEM results show that the resultant bimetallic nanoparticles disperse uniformly on Ni foil with a narrow size distribution. The apparent size of bimetallic nanoparticles deposited on Ni depends on the reaction time of self-assembly. The TEM results reveal that the Pd–Au bimetallic nanoparticles consist of smaller homogeneous alloy nanoparticles with an average diameter of 5.1 nm, size of which depends on the size of micro water droplets. The growth mechanism of the Pd–Au nanoparticles in microemulsion was also explored. The electrocatalytic performance of the Pd–Au NPs/Ni electrode was studied by cyclic voltammetric and chronoamperometric measurements. Electrochemical experiments show that the Pd–Au nanoparticles have good catalytic activity and good stability for ethanol oxidation in alkaline media.
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Soft Matter
·
2013
·Vol. 9
·期 48
·11585-11597
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IF 3.909
Wenlong Li,Peiyi Wu
The dynamic thermally reversible phase transition behaviour of poly(ethylene oxide) (PEO) in 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) has been investigated by calorimetric measurements (DSC) and FT-IR, in combination with perturbation correlation moving window (PCMW) and two-dimensional correlation spectroscopy (2DCOS) for the first time. A relatively high lower critical solution temperature (LCST) was observed which is different from that of conventional thermo-sensitive polymers in aqueous solution. Four types of hydrogen bonds were found in this system, among which the type I (the hydrogen bonds between the unsaturated C–H on the imidazole ring and the oxygen atoms of PEO) and type II (the hydrogen bonds between the saturated C–H on the PEO backbone and the fluorine atoms of the IL anions) ones have a more predominant influence on the phase transition. Moreover, type I plays the predominant role in both the heating and cooling process. DSC revealed that the phase transition temperature of PEO–[EMIM][BF4] solutions decreases with the increasing concentration of PEO, as well as with a decreasing scanning rate. Through PCMW, the LCST was determined to be ca. 137 °C during heating and ca. 131 °C during cooling. Finally, 2DCOS was employed to elucidate the dynamic mechanism of PEO in [EMIM][BF4], which revealed hydrogen bond disruption, chain aggregation and exclusion of IL molecules. Solutions with a low PEO concentration tend to form loosely aggregated globules, compared to the more densely aggregated globules in samples with a high PEO concentration. Additionally, it is worth mentioning that several unusual and peculiar phenomena were also observed, such as opposite frequency shifts in C–H groups, a “tail-raising” phenomenon, critical PEO concentration for the phase transition temperature, and intersection of the frequency shift curves for samples with high concentrations of PEO during cooling.
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Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 14
·7568-7574
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IF 7.443
Fang Liao,Xun Song,Siwei Yang,Chenyao Hu,Lin He,Shuai Yan,Guqiao Ding
We demonstrate a new semiconducting polymer dot: the poly(o-phenylenediamine)–Rhodamine B copolymer dot (Pp–RhB dot), which emits in the red wavelength range. The Pp–RhB dots can be used as an ultrasensitive fluorescence probe for NO2−in vivo and show high selectivity and ultrasensitivity (detection limit: 2.0 × 10−11 M) for NO2−. The fluorescence of Pp–RhB dots is decreased (φ = 0.014) as a result of fast photoinduced electron transfer (PET) between the modulator (poly(o-phenylenediamine)) and the transducer (RhB), but the N–NO2 bonding mode prevents PET, causing the fluorescence emission to be enhanced (φ = 0.92). This probe effectively avoids the influence of auto-fluorescence in biological systems and gave positive results when tested in both aqueous solution and living cells.
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ACS Nano
·
2015
·
IF 12.881
Shuang Jiao,Qing Shen,Iván Mora-Seró,Jin Wang,Zhenxiao Pan,Ke Zhao,Yuki Kuga,Xinhua Zhong,Juan Bisquert
Even though previously reported CdTe/CdSe type-II core/shell QD sensitizers possess intrinsic superior optoelectronic properties (such as wide absorption range, fast charge separation, and slow charge recombination) in serving as light absorbers, the efficiency of the resultant solar cell is still limited by the relatively low photovoltage. To further enhance photovoltage and cell efficiency accordingly, ZnTe/CdSe type-II core/shell QDs with much larger conduction band (CB) offset in comparison with that of CdTe/CdSe (1.22 eV vs 0.27 eV) are adopted as sensitizers in the construction of quantum dot sensitized solar cells (QDSCs). The augment of band offset produces an increase of the charge accumulation across the QD/TiO2 interface under illumination and induces stronger dipole effects, therefore bringing forward an upward shift of the TiO2 CB edge after sensitization and resulting in enhancement of the photovoltage of the resultant cell devices. The variation of relative chemical capacitance, Cμ, between ZnTe/CdSe and reference CdTe/CdSe cells extracted from impedance spectroscopy (IS) characterization under dark and illumination conditions clearly demonstrates that, under light irradiation conditions, the sensitization of ZnTe/CdSe QDs upshifts the CB edge of TiO2 by the level of ∼50 mV related to that in the reference cell and results in the enhancement of Voc of the corresponding cell devices. In addition, charge extraction measurements have also confirmed the photovoltage enhancement in the ZnTe/CdSe cell related to reference CdTe/CdSe cell. Furthermore, transient grating (TG) measurements have revealed a faster electron injection rate for the ZnTe/CdSe-based QDSCs in comparison with the CdSe cells. The resultant ZnTe/CdSe QD-based QDSCs exhibit a champion power conversion efficiency of 7.17% and a certified efficiency of 6.82% under AM 1.5G full one sun illumination, which is, as far as we know, one of the highest efficiencies for liquid-junction QDSCs.
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高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Qian Zhang,Ting Yin,Guo Gao,Joseph G. Shapter,Weien Lai,Peng Huang,Wen Qi,Jie Song,Daxiang Cui
Core@shell magnetic nanoparticles (core@shell MNPs) are attracting widespread attention due to their enhancement properties for potential applications in hyperthermia treatment, magnetic resonance imaging (MRI), diagnostics, and so forth. Herein, we developed a facile thermal decomposition method for controllable synthesis of a superparamagnetic, monodispersed core@shell structure (Co@Mn = CoFe2O4@MnFe2O4) with uniform size distribution (σ < 5%, dc ≈ 15 nm). The CoFe2O4 core could enhance magnetic anisotropy, and the MnFe2O4 shell could improve the magnetization value. The Co@Mn MNPs were transferred into aqueous solution with an amphiphilic polymer (labeled 2% TAMRA) and functionalized with PEG2k and target molecules (folic acid, FA) to fabricate multifunctional PMATAMRA-Co@Mn-PEG2k-FA nanoprobes. The obtained PMATAMRA-Co@Mn-PEG2k-FA nanoprobes exhibit good biocompatibility, high T2 relaxation values, and long-term fluorescence stability (at least 6 months). Our results demonstrate that the synthesized PMATAMRA-Co@Mn-PEG2k-FA nanoprobes can effectively enhance the targeted MRI and fluorescent labeling in vitro and in vivo. The research outcomes will contribute to the rational design of new nanoprobes and provide a promising pathway to promote core@shell nanoprobes for further clinical contrast MRI and photodynamic therapy in the near future.
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RSC Advances
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2015
·Vol. 5
·期 114
·94008-94015
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IF 3.84
Fen Guo,Ke Ye,Xiaomei Huang,Yinyi Gao,Kui Cheng,Guiling Wang,Dianxue Cao
A novel Pd/polyaniline/CFC electrode is prepared by electroless deposition of palladium (Pd) onto three-dimensional polyaniline networks. The polyaniline matrix on the carbon fiber cloth (CFC) in the reduction state is electro-synthesized by cyclic voltammetry and has a lower vertex potential of −0.4 V vs. Ag/AgCl. The particle size of the Pd coated on the polyaniline chains is gradiently distributed. The as-prepared Pd/polyaniline/CFC electrode is characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FITR) and X-ray diffraction (XRD). The hydrogen peroxide (H2O2) electro-reduction reaction in H2SO4 solutions on the Pd/polyaniline/CFC electrode is investigated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The results reveal that the electrode exhibited high catalytic activity and excellent stability in the strong oxidizing solution of H2O2 and H2SO4. Polyaniline itself shows electro-catalytic activity towards H2O2 to some extent involving the chemical–electrochemical (C–E) coupling mechanism.
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ANALYST
·
2017
·Vol. 142
·期 9
·1452-1458
·
IF 3.885
Li Liu,Limin Zhang,Zhihui Dai,Yang Tian
Nitric oxide (NO) is key free-radical messenger and neuronal signal which is closely related to many brain diseases. It is a challenge to develop a sensitive and reliable biosensor for in vivo monitoring of NO in the brain. In this research, a simple ratiometric electrochemical biosensor for NO monitoring in rat brain following cerebral ischemia was developed using a carbon nanotube fiber (CNF) modified with hemin, in which the CNF not only served as a platform to assemble the hemin molecule, but greatly facilitated the electron transfer of hemin on to the electrode surface. Additionally, the hemin molecule was found to play dual roles: as a stable catalyst for the reduction of NO for selective detection of NO at −0.67 V versus silver/silver chloride, as well as an inner reference element to provide a built-in correction, to avoid the interference from the complicated brain environment. The developed ratiometric biosensor can detect NO with a linear range from 25 to 1000 nM, with a low limit of detection down to 10 nM, which fulfills the requirements for in vivo measurement of NO. The remarkable analytical performance of the present biosensor, as well as the long-term stability and good reproducibility established this as a reliable approach for in vivo monitoring of NO in the hippocampus of rat brains following cerebral ischemia. This is the first report that the average level of NO increased from 61 ± 23 nM to 141 ± 18 nM after cerebral ischemia for 15 min.
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POSTHARVEST BIOLOGY AND TECHNOLOGY
·
2024
·
IF 6.4
Hua Huang,Xuemei He,Qingming Sun,Guoming Liu,Yayuan Tang,Jian Sun
Pitaya ( Hylocereus undatus ) fruit is susceptible to pathogens that induce fruit decay after harvest. Cuticular waxes covering the outermost plant surfaces are the first site of plant-environment interactions; however, their changes in response to fruit decay are under-researched. Herein, the surface microstructures and chemical composition of wax on pitayas, as well as their changes in response to fruit decay, were comparatively studied. The varieties ‘Baishuijing’ (BSJ) and ‘Hongshuijing’ (HSJ) were examined after harvest. The fruit appearance, morphology, and wax composition differed between cultivars. The surface of both pitaya cultivars was smooth, although traces of granules and a thicker lipid layer were observed using histochemical staining in HSJ than in BSJ, as well as a higher cuticular wax content. Fruit decay rate increased rapidly in both cultivars under room storage conditions, and greater sensitivity to pathogens was found in BSJ than HSJ. As well as the occurrence of fruit decay, the total wax coverage, very-long-chain primary alcohols, aldehydes, fatty acids, and triterpenoids decreased in BSJ, while remaining relatively stable in HSJ. Correspondingly, the relative gene expression levels of HuKCS11 (−1, 2, and 3) , HuKCS17 , and HuKCS19 (for the elongation of very-long-chain fatty acids), HuCER1 (for aldehydes or n -alkanes), HuFAR (−1 and 2) (for primary alcohols), HuBAS1 (−1, 3, and 4) (for β-amyrin), and HuLUS1 (for lupeol) were considerably modified following fruit senescence during storage. The difference in surface topography and wax accumulation between cultivars might have affected pathogen susceptibility after harvest. These results may help when choosing varieties of pitaya based on surface characteristics and cuticular chemicals. They may also help to optimize strategies for postharvest preservation and storage.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2025
·
IF 8
Bangyu Chen,Hui Shen,Yifan Jin,Qiang Wu,Jiangmin Liu,Xueyu Wang,Xinru Zhang,Haiying Yu
Chlorinated benzoquinones (CBQs) are a class of disinfection byproducts (DBPs) that are widely present in aquatic environments. Due to their strong cytotoxicity and genotoxicity to aquatic organisms and humans, the identification of novel CBQs and the exploration of their formation mechanisms became the focus of recent research. In this study, a new group of chlorinated DBPs formed during chlorination of two aromatic amino acids, tyrosine (Tyr) and tryptophan (Trp), were identified for the first time. Four predominant formation pathways of the main chlorinated product from Tyr and Trp, dichloro-benzoquinone (DCBQ), were deduced based on the MASS spectrum data, which consist of reactions including electrophilic addition, chlorination, hydrolysis, decarboxylation, oxidation, dehydrochlorination, and cleavage of the pyrrole ring. The potential chlorination substituted sites of Tyr to form 2,6-DCBQ were further explored by quantum chemical calculations. Chlorination tended to occur at the ortho C-position of the –OH (hydroxyl) group in Tyr. The C1 site of Tyr was most prone to undergo monochlorination, and dichlorination was more likely to take place at C5 site of the monochlorinated product. In addition, the nitrogen atom (N18) of Tyr could also undergo chlorine substitution, but it was difficult to happen when the C1 and C5 sites were already substituted. By combining experimental and theoretical results, this study summarized the predominant pathway for the formation of 2,6-DCBQ during the chlorination process of amino acids. The outcome contributed to a deeper understanding of the implications for water safety and the potential health risks associated with chlorination byproducts.
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POLYMER COMPOSITES
·
2024
·
IF 4.8
Peixing Li,Haoze Yuan,Xinyu Wang,Cheng Yu,Xin Wang,Jutao Sun
The crystalline cellulose has captured much attention as reinforcement material in rubber composites, but no successful cases have been found till now. Here, a facile approach of cellulose utilization was proposed by in-situ regenerating cellulose in dry rubber matrix. Cellulose was dissolved in ionic liquid (IL), and then directly mixed with dry rubber, silica, and other ingredients. Taking advantages of the strong interaction between IL and silica, the dissolution equilibrium of cellulose/IL was destroyed and resulted in the regeneration of cellulose crystals in rubber matrix. The regenerated cellulose appeared at dry blending stage, and showed an ideal rod-like shape (10–100 nm in diameter and 200–500 nm in length). While it grew in size at curing stage, and finally reached 100–200 nm in diameter and 1–2 μm in length. The regenerated cellulose exhibited pronounced reinforcement efficiency. This methodology has no any waste liquid discharged, and has a promising use in the preparation of cellulose/rubber composites. Highlights Nanosized rod-like cellulose was regenerated in dry rubber, instead of latex. Regeneration of cellulose was due to interaction between ionic liquid and silica. The in situ regenerated cellulose dispersed well in cured rubber compounds. The regenerated cellulose exhibited a good reinforcement efficiency in rubber. The whole machining process had no any waste liquid discharged.
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ELECTROCHIMICA ACTA
·
2025
·
IF 5.6
Hongdi Zheng,Liuyan Zhang,Yingying Li,Binkai Yuan,Shixuan Wang,Zeyi Guan,Gengzhe Shen,Guibin Tan,Yanmei Zhang
A honeycomb-like porous self-supporting Ni-Al(G) electrode was successfully prepared by low-pressure cold spraying combined with heat treatment. The main components of the electrode were Ni and NiAl. Graphene was uniformly dispersed throughout the electrode, exhibiting a 3-D distribution, which increased the active site of electrode and improved the electron exchange rate. The electrochemical properties of the Ni-Al(G) electrode were characterized using 6 M KOH. As a result, the Ni-Al(G) electrode requires only an overpotential of 130 mV to achieve a current density of 100 mA cm −2 , and a Tafel slope of 35.5 mV dec −1 . In addition, the electrode exhibited excellent stability. The addition of graphene and the honeycomb-like porous structure of the Ni-Al(G) electrode resulted in an excellent hydrogen evolution activity. This study provides a simple and rapid technique for building high-performance, low-cost, and industrially available electrodes for the efficient alkaline HER.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Qian-Qian Tang,Bang-Xiang Wu,Xiao-Wen Huang,Yi Hu,Dongmei Hou,Wei Ren,Ling-Ling Liu,Ying Chen,Lei Tian,Long-Shuai Zhang,Qing Sun,Jian-Ping Zou
Highly selective generation of singlet oxygen ( 1 O 2 ) in the electro-Fenton system remains challenging due to susceptibility of the O-O bond to break in O 2 reduction reaction and activation process of H 2 O 2 . Herein, the nitrogen-coordinated Fe single-atom catalyst with a high coordination number (FeN 6 /CN) was synthesized, allowing the Fe sites to remain trivalent while presenting a high spin state. The quenching experiments and EPR tests proved that the electro-Fenton system of FeN 6 /CN achieved high selectivity generation of 1 O 2 , showing excellent degradation performance of different organic pollutants. Combined with theoretical calculations, the FeN 6 sites displayed a lower energy barrier for the transfer from *H 2 O 2 to 1 O 2 . In the FeN 6 /CN’s electro-Fenton system, the high spin state of FeN 6 site ensured generation of H 2 O 2 via 2e - reduction. Simultaneously, the high oxidation state of FeN 6 site further achieved a highly selective generation of 1 O 2 by in situ activation of H 2 O 2 in the electro-Fenton system. Particularly, the FeN 6 /CN’s electro-Fenton system showed a high energy-efficient for pollutant removal (23.79 kWh·kg toc −1 ) compared to other electro-Fenton systems (50–300 kWh·kg toc −1 ). The electronic structure regulation of single atom sites provides a new avenue for highly selective generation of 1 O 2 in the electro-Fenton system.
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