查找使用阿拉丁产品的科研文献

Synthesis and upconversion luminescent properties of Bi2MoO6:20%Yb3+, 2%Er3+ hollow microsphere with different W6+ ions doping

Wen Ge,Kong Liu,Peizhi Yang,Shukang Deng,Lanxian Shen

In this work, W 6+ ions doped Bi 2 MoO 6 :20%Yb 3+ , 2%Er 3+ samples were successfully synthesized by a facile and modified hydrothermal method . The main morphology of Bi 2 MoO 6 samples were hollow microsphere structure assembled by nanosheets . The particle size was slightly increased as enhancing W 6+ ions doping concentration to 5%, then decreased as the doping concentration increased. Besides, doping W 6+ ions can increase the band gap of products from 2.65 ​eV to 2.71eV. The upconversion emission intensity of all samples was strongly influenced by the W 6+ ions doping concentration. The luminescent intensity enhanced with the doping concentration increasing up to 3%, then decreased when the W 6+ ions concentration further increased. Moreover, the intensity of red emission increased by a large margin than that of green-light region. Besides, the lifetime of 4 F 9/2 states of Er 3+ ions for Bi 2 MoO 6 :20%Yb 3+ , 2%Er 3+ , 3%W 6+ (τ 655  ​= ​583.64 ​μs) had significant longer lifetime relative to the Bi 2 MoO 6 :20%Yb 3+ , 2%Er 3+ (τ 655  ​= ​70.29 ​μs).

Thermo-associating polymers based on cross-linked 2-acrylamido-methylpropane sulfonic acid, part A: Synthesis and solution behavior

Alain Pierre Tchameni,Binqiang Xie,Hui Zhang,Lin Zhao,Mingwang Luo,Jiantai Wen

A novel thermo-thickening hydrophilic copolymer (CGBA) was prepared by free-radical copolymerization of sodium 2-acrylamido-2-methylpropane sulfonic acid (NaAMPS) with a newly-synthesized thermo-sensitive macromonomer (BA) and cross-linking N,N’-methylenebisacrylamide (MBA) in aqueous solution under optimal conditions. Its aqueous solution viscosity behavior with respect to temperature was preliminarily evaluated in comparison with its cross-linked sulfonated copolymer (CPAMPS) counterpart (without BA side-chains). Particular attention is dedicated to the thermo-thickening of the aqueous copolymer solutions as studied by the viscosity measurements . In pure water, and above 0.5 wt.%, CGBA manifested an abrupt macroscopic property above the critical association temperature ( T cass ), while CPAMPS exhibited shear-thinning behavior following an Arrhenius law under the same conditions. The composition and length of BA side-chains were identified as the key parameters to envision the self-assembling behavior of CGBA. The results obtained from complementary experiments, performed by proton nuclear magnetic resonance ( 1 H-NMR), Differential scanning calorimetry (DSC), and pyrene fluorescence showed the phase transition of BA side-chains above the T cass . In addition, well above the T cass (70 and 80 °C), the oscillatory shear experiments proved that the storage and loss modulus could be fitted with the single relation time Maxwell model at low frequencies. Furthermore, the magnitude of the thickening effect and the T cass could be modulated using external factors such as shear rates, salinity, and pH. This, in combination with the cost-effectiveness, and the need to further broaden the established theory of thermo-sensitive comonomer, make this copolymer especially interesting for application not only in polymer flooding, but also in drilling fluid.

pH-Dependent thermoresponsive poly[2-(diethylamino)ethyl acrylamide]-grafted PVDF membranes with switchable wettability for efficient emulsion separation

Yupei Xian,Yonggang Shui,Meimei Li,Cunbao Pei,Qiyi Zhang,Yongyi Yao

Plenty of oily wastewater discharged from industrial and domestic sewage has deteriorated the environment severely, so stimuli-responsive membranes with switchable wettability have been of considerable attraction for its potential application in oil/water separation. In this work, a novel pH-dependent thermoresponsive membrane fabricated by grafting the poly[2-(diethylamino)ethyl acrylamide] (PDEAEAM) from the poly(vinylidene fluoride) (PVDF) membrane via surface-initiated atom transfer radical polymerization is explored to achieve the oil/water separation. The PDEAEAM- g -PVDF membrane shows hydrophilicity at room temperature under neutral condition while hydrophobicity at 50°C under alkaline condition. Wettability of the membrane at different temperatures is dominated by the lower critical solution temperature (LCST) of PDEAEAM, and the LCST of PDEAEAM is pH dependent. Due to the LCST of PDEAEAM, the membrane shows a variation of separation efficiency for separating hexadecane/water emulsion with temperature and pH. Typical separation efficiencies are 97.10% at 25°C under neutral condition and 30.26% at 50°C under alkaline condition.

Interfacial electronic interaction of atomically dispersed IrClx on ultrathin Co(OH)2/CNTs for efficient electrocatalytic water oxidation

Yiwen Huang,Guijuan Wei,Jia He,Cuihua An,Min Hu,Miao Shu,Junfa Zhu,Shuang Yao,Wei Xi,Rui Si,Zhi-Ming Zhang,Changhua An

The exploration of highly-efficient oxygen evolution reaction (OER) electrocatalyst with well-defined structure to understand specific structure-performance relationship is crucial to meet the requirement of water-splitting. Herein, we firstly used atomically dispersed IrCl x to uniformly decorate ultrathin Co(OH) 2 nanosheets to dramatically improve electrocatalytic activity. The synthesized IrCl x -Co(OH) 2 nanosheets/carbon nanotubes (CNTs) exhibits an overpotential of 230 mV to reach 10 mA/cm 2 , which was much enhanced compared to that of pristine Co(OH) 2 /CNTs (308 mV) and commercial benchmark IrO 2 (309 mV). X-ray absorption fine structure and density functional theory simulations demonstrate strong interfacial interaction between IrCl x and Co(OH) 2 nanosheets via the Cl-Ir-O and Ir-Cl-Co bond can efficiently boost its electronic conductivity. The accelerated charge transfer promotes the formation of more positively charged O atoms around cobalt centers, which is beneficial for the deprotonation on IrCl x -Co(OH) 2 and makes the catalyst facilitate OER.

Dielectric strength of glass fibre fabric reinforced epoxy by nano-Al2O3

Shuang Wang,Yu Chen,Jiale Mao,Cong Liu,Lei Zhang,Yonghong Cheng,Chaoyun Du,Toshikatsu Tanaka

The effect of Fe(III) cations in electrolyte on oxygen evolution catalytic activity of Ni(OH)2 electrode

Jiuli Chang,Liming Chen,Shiqi Zang,Yifan Wang,Dapeng Wu,Fang Xu,Kai Jiang,Zhiyong Gao

A facile and efficient oxygen evolution reaction (OER) catalytic system was constructed based on interconnected Ni(OH) 2 nanosheets arrays electrode and Fe(III) containing alkali electrolyte. The partial deposition of Fe(III) onto Ni(OH) 2 with heterostructure obviously enhanced the OER current density and reduced the overpotential, and the Fe(III) cations in electrolyte also furnished positive contribution to the catalytic reaction, the synergy between Ni(OH) 2 electrode and Fe(III) cations in electrolyte therefore substantially improved the OER catalytic efficiency with low overpotential (285 mV at current density of 50 mA cm −2 ) and obviously enhanced current density (391 mA cm −2 at 1.8 V). The current work expands our understanding on the effect of Fe(III) cations in electrolyte to OER efficiency of Ni based catalyst, and opens up a cost-effective and practical avenue to enhance the OER catalytic efficiency by introducing metal cations in alkali electrolyte.

Fluoxetine exposure for more than 2 days decreases the neuronal plasticity mediated by CRMP2 in differentiated PC12 cells

Zuotian Wu,Gaohua Wang,Huiling Wang,Ling Xiao,Yanyan Wei,Can Yang

Background Recent studies indicate that antidepressants treatment restores neuronal plasticity. In contrast, some researchers claim that serotonergic antidepressants, including fluoxetine (FLU), may exacerbate neuronal plasticity, which is contradictory and rarely studied. Since almost those studies exposed cells with drugs for 1–2 days as treatment models of antidepressants, it is possible that FLU exposure for longer periods would have opposite effects on neuronal plasticity. Results In the present study, we examined the effects of FLU exposure (up to 3 days) on the neuronal plasticity in differentiated PC12 cells. The cell viability shown a slight decrease at day 2 (93.5 ± 3.5 %), followed by a highly significant decrease at day 3(71.4 ± 4.4 %). As previously reported, neuronal plasticity was significantly upregulated by FLU exposure at day 1. However, the neurite length, activity-regulated cytoskeleton-associated protein (Arc) and c-Fos mRNA were inhibited with FLU exposure at day 3. Similarly, the expression of tubulin, which play important roles in the neuronal plasticity, was the same result. Furthermore, we found α-tubulin interacted with collapsing response mediator protein 2(CRMP2), which is related to neuronal plasticity, and the regulation of CRMP2 activity influenced the neurite length, Arc, c-Fos and tubulin expression. Conclusions The results demonstrated that neuronal plasticity was increased by FLU exposure at day 1, but exposure with FLU for more than 2 days had opposite effect on it. The reduction in neuronal plasticity with FLU exposure for more than 2 days might be involved in some aspects of the therapeutic effect of antidepressant on depression.

Removal of meloxicam, piroxicam and Cd+2 by Fe3O4/SiO2/glycidyl methacrylate-S-SH nanocomposite loaded with laccase

Saifeldin M. Siddeeg,Abdelfattah Amari,Mohamed A. Tahoon,Norah Salem Alsaiari,Faouzi Ben Rebah

For the simultaneous removal of water contaminants, a novel nanocomposite has been produced. The iron oxide core with silica shell was used to prepare functional magnetic polymer Fe 3 O 4 /SiO 2 /glycidyl methacrylate (GMA)-S-SH nanocomposite. The sulfur functional nanocomposite is suitable for the immobilization of laccase enzyme. The synthesized nanocomposite was characterized using FT-IR spectroscopy, SEM, TEM, XRD, and magnetometer. The effect of pH, temperature, and storage time over free and immobilized enzyme was studied that indicating the higher stability of immobilized enzyme than that free one. The prepared novel nanocomposite showed high adsorption capacity toward Cd +2 ions in addition to the degradation of meloxicam and piroxicam anti-inflammatory drugs. The removal efficiency reached up to 94% ± 2%, 92% ± 2%, and 95% ± 2% for Cd +2 ions, meloxicam, and piroxicam, respectively at optimum pH and temperature. Also, the results show that this nanocomposite is recyclable. The efficient removal of Cd +2 ions and pharmaceuticals can be reached up to four cycles. We conclude that the prepared nanocomposite is promising for water treatment.

Design and fabrication of Ni(OH)2/BiVO4 heterostructured nano-photocatalyst for high-efficient removal of organic dyes

Nihad Ibrahim Mohammed Abdallah,Yan Li,Xiao-Tian Wang,Xue Li,Cheng-Wei Wang

Configuring new nanostructured photocatalyst with high efficient photocatalystic capabilities is meaningfully for environmental pollution control. Herein, a p-n heterojunction nanostructured photocatalyst of Ni(OH) 2 /BiVO 4 was well designed and successfully fabricated via a facile solvothermal method, in which Ni(OH) 2 is a wide band-gap semiconductor. Being applied for photo-degradation of anion organic dye, it is found such Ni(OH) 2 /BiVO 4 heterostructures can not only increase the specific surface area and enhance the light response, but also effectively facilitate the photo-generated charge separation and transfer. As a result, 0.5-Ni(OH) 2 /BiVO 4 can possess a photocatalytic capability of 96% and a reaction rate constant 1.9572 h −1 within 90 min irradiation, being 6 and 18 times higher than that of pure BiVO 4 (16%, 0.1098 h −1 ). This study presents a new means to design a kind of high efficient wide band-gap semiconductor constructed BiVO 4 -based photocatalysts.

Confined synthesis of carbon dots with tunable long-wavelength emission in a 2-dimensional layered double hydroxide matrix

Wendi Liu,Ruizheng Liang,Yanjun Lin

Fluorescent carbon dots (CDs) have drawn significant attention due to their variable species and intriguing optical properties; however, spectrally tuning the fluorescence color of CDs, especially in a long-wavelength region, is still a challenge. In this study, CDs were synthesized through the hydrothermal reaction of 2,5-diaminobenzenesulfonate (DBS) and dodecyl sulfate (DS) in the confined interlayer space of layered double hydroxides (LDHs). Particularly, the emission color of the obtained CD/LDH phosphors could be spectrally tuned from greenish-yellow (λem = 537 nm) to red (λem = 597 nm) by simply changing the molar ratio of the intercalated DBS and DS. Through the detailed characterization of different interlayer CDs by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, elemental analysis, and X-ray photoelectron spectroscopy (XPS), a new route of modulating the absorption and emission wavelengths of CDs by regulating the content of graphitic nitrogen during heteroatom doping is presented. In addition, the stabilities of the solid-state luminescence against UV bleaching and temperature variation were improved by the rigid 2-dimensional (2D) LDH matrix, and prospective applications of the proposed CD/LDH phosphors were demonstrated in multicolour displays and in the fabrication of white light-emitting diodes (WLEDs).

Electrocatalytic hydrogen evolution properties of anionic NiS2-Ni(OH)2 nanosheets produced on the surface of nickel foam

Mojie Sun,Zhao Wang,Bixue Gao,Shijie Wang,Chi Wang,Xiaochen Song,Dongyao Lin

Summary To circumvent the expensive cost of precious metal electrocatalysts, a hydrothermal method and a plasma-enhanced chemical vapor deposition (PECVD) method have been used to prepareNiS 2 -Ni(OH) 2 /NF-PECVD (N-PECVD) with excellent properties. After XRD, SEM, XPS, and other characterization methods, it can be seen that after the hydrothermal reaction of Ni foam (NF), 50-60 nm Ni(OH) 2 nanosheets have grown on the NF frame. The subsequent PECVD reaction produces 90 nm NiS 2 -Ni(OH) 2 nanosheets on the NF frame. The hydrogen release overpotentials in the acidic solution and alkaline solution are 90 and 95 mV ( j = 10 mA/cm 2 ), respectively. And the Tafel slopes reach 80 and 83.6 mV/dec, respectively. The chronopotential (CP) test shows that the material has good HER stability over 12 h. The results from the subsequent electric double layer capacitance and alternating current impedance (EIS) tests show that N-PECVD synthesized by PECVD has a relatively large active electrochemical surface area (ECSA) and a low electrochemical impedance. This study not only finds good inspiration for the synthesis of cheap HER catalysts but also provides a valuable reference for the synthesis of materials in other fields.

Emulsion-Tailored Pore Properties and Electrochemical Performance of Ni(OH)2 Spheres Using High Shear as Driving Force

Jingxue Zhang,Hongtao Cui

The pore-structural ordering in nanosheets-interlinked clusters is a significant issue for the electrochemical performance of Ni(OH) 2 as an electrode material for application in Faraday supercapacitors. Herein, the W/O emulsion stabilized by high shear mixer (HSM) is used as a medium to organize the pore structure in Ni(OH) 2 nanosheets-interlinked spheres. It is found that the water content in emulsion strongly affects the pore structure and surface area of Ni(OH) 2 nanosheets-interlinked spheres formed through the granulation effect of HSM. It is considered that the oil phase as continuous phase in emulsion can reduce the aggregation/agglomeration of Ni(OH) 2 nanosheets, resulting from the strong intermolecular force between nanosheets. As a result, the oil phase in emulsion is beneficial to the formation of ordered pore structure and the increase of surface area in the produced spheres. The characterization results indicate that the sample prepared at a water content of 20 vol% has the largest specific surface area and the well-defined pore structure enclosed with interlinked nanosheets. As a result, this sample presents excellent electrochemical performance and promoted cycling stability.