Intriguing anti-superbug Cu2O@ZrP hybrid nanosheet with enhanced antibacterial performance and weak cytotoxicity

In view of it’s strong antibacterial function and minor toxicity, cuprous oxide (Cu₂O) is frequently used in various broad-spectrum antibacterial reagents. Nonetheless the undesirable effects of superbugs still remain challenging. In this research, a chemical deposition approach is used to prepare a Cu₂O@ZrP composite with nanosheet configuration demonstrating excellent dispersibility and antibacterial traits. From systematic analysis, it was inffered that the content of copper in the nanosheet was about 57–188 mg/g while the average thickness of the nanosheets Cu₂O formed on ZrP is approximately 0.8 nm. The results of the minimal inhibitory concentration (MIC) revealed that an extremely low loading of Cu₂O in Cu₂O@ZrP nanosheet can lead to exceptional antibacterial activity. Examined on two various superbugs; i.e. methicillin-resistant staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE), the composite nanosheet reagent performed over 99% microbial reduction. More intesetingly, the cell growth rate of the Cu₂O@ZrP nanosheet was determined to be 20% lower than that of the neat Cu₂O, manifesting a weaker cytotoxicity. This unique hybrid nanosheet with intriguing anti-superbug performance promises highly efficient protection for the fabrics, battledress, and medical textiles.

     

Preparation and electrochemical performance of alpha-nickel hydroxide nanowire

Alpha-nickel hydroxide nanowire with diameter of 60 nm was successfully synthesized by conversely migrates technique. Structural and morphological characterizations were performed using power X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The capacitive properties were evaluated by cyclic voltammetry (CV), galvanostatic charge–discharge and electrochemical impedance spectroscopy technique in 6 M KOH aqueous electrolyte. A maximum specific capacitance of 833 F g⁻¹ was obtained at constant current of 5 mA, indicating that the α-nickel hydroxide nanowire is a promising electrode material for electrochemical capacitors.     

Preparation and electrochemical performance of nano-scale nickel hydroxide with different shapes

Platelet-like, flake-like, and needle-like nano-scale β-Ni(OH)₂ particles were prepared by coordination homogeneous precipitation method in this paper. X-ray diffraction (XRD), transmission electron microscopy (TEM) and infrared absorption spectra (IR) were used to characterize the microstructure and morphology of the products. The nano-scale Ni(OH)₂ composite electrodes were prepared by mixing 10 wt.% samples with spherical Ni(OH)₂ to carry out charge-discharge test. The results show that the nano-scale Ni(OH)₂ composite electrodes have higher discharge specific capacity, and the nickel hydroxide nanoneedles show a better adulteration performance than the others.     

Al取代α-Ni(OH)2 的有机溶剂法合成及其电化学性能

采用化学共沉淀法,在醇水溶剂体系中合成了Al取代的α-Ni(OH)2.应用AAS、ICP-AES技术测定了样品中元素Ni和Al的含量,并运用XRD、FTIR和TG-DSC等现代分析手段,对其结构进行了表征.所得产品的密度为1.68g*cm-3,放电中点电位为370mV,电化学比容量达303mA*h*g-1.经372个大电流充放电循环,样品的电化学容量循环衰减率仅为9.6%.     

Structure and electrochemical performance of nickel hydroxide synthesized by rapid quench method

Nickel hydroxide with amorphous structure has been synthesized successfully by chemical precipitation method combined with rapid quench technique. The microstructure and morphology of the prepared samples were analyzed by XRD, Raman spectra, IR spectra, and SEM. The electrochemical performance of the sample was characterized by cyclic voltammetry, electrochemical impedance spectroscopy, and charge/discharge tests. The discharge capacity of the amorphous nickel hydroxide is 330.0 mAh g⁻¹ at 0.2C, much higher than that of the theoretical capacity of β-nickel hydroxide (289.0 mAh g⁻¹). Moreover, the amorphous nickel hydroxide exhibits higher electrochemical reaction reversibility, lower electrochemical impedance, and better cyclic stability compared with β-nickel hydroxide.     

Fabrication of porous low crystalline calcite block by carbonation of calcium hydroxide compact

Calcium carbonate (CaCO₃) has been widely used as a bone substitute material because of its excellent tissue response and good resorbability. In this experimental study, we propose a new method obtaining porous CaCO₃ monolith for an artificial bone substitute. In the method, calcium hydroxide compacts were exposed to carbon dioxide saturated with water vapor at room temperature. Carbonation completed within 3 days and calcite was the only product. The mechanical strength of CaCO₃ monolith increased with carbonation period and molding pressure. Development of mechanical strength proceeded through two steps; the first rapid increase by bonding with calcite layer formed at the surface of calcium hydroxide particles and the latter increase by the full conversion of calcium hydroxide to calcite. The latter process was thought to be controlled by the diffusion of CO₂ through micropores in the surface calcite layer. Porosity of calcite blocks thus prepared had 36.8–48.1% depending on molding pressure between 1 MPa and 5 MPa. We concluded that the present method may be useful for the preparation of bone substitutes or the preparation of source material for bone substitutes since this method succeeded in fabricating a low-crystalline, and thus a highly reactive, porous calcite block.     

Fabrication of an atomic resolution low cost STM-SNOM hybrid probe

We derived a simple method to fabricate STM-SNOM hybrid probes obtained from commercial cheap communication optical fibers. The tips are fabricated by a methodology that combines two well-known techniques: the selective attack by a buffered solution and the protected layer chemical etching, in a single new one-step technique. The tailored probes are then sputtered by metal and mounted on a STM setup. The usual difficulties of integrating the optical fiber in the STM head are solved originally with a particular home made mount described in details. We will show that the resulting probes reach atomic resolution on both vertical and horizontal scale, and that the optical imaging is free of artifacts and satisfactory with a lateral resolution in the order of lamda/20, as far as we know the finest resolution obtained with a system based on a hybrid fiber probe. We believe that our methodology is very interesting for its simplicity of realization and for the good resolving power in both SNOM and STM modes.     

Fabrication of a nanocrystalline Ni-Co/CoO functionally graded layer with excellent electrochemical corrosion and tribological performance

Nanocrystalline (NC) Ni-Co/CoO functionally graded materials with excellent lubricating, high anti-corrosion and anti-wear performance were fabricated by electrodeposition and subsequent cyclic thermal oxidation and quenching. Transmission electron microscopy and energy dispersive x-ray spectroscopy investigations show that bulk Ni-Co gradient deposits with an average grain size in the range of 13-40?nm demonstrated a graded structure transition from face-centred cubic to hexagonal close packed and graded composition changes from Ni-rich to Co-rich regions with the increase in deposit thickness. X-ray diffraction and x-ray photoelectron spectroscopy analysis indicated the surface layer of NC Ni-Co graded materials to be mainly composed of dense and ultrafine CoO with a (111) preferred orientation. The NC Ni-Co/CoO functionally graded materials exhibited significantly enhanced corrosion resistance in both NaOH and NaCl solutions and remarkably improved wear resistance and dry self-lubricating performance when compared with the NC Ni and Ni-Co graded deposits under dry sliding wear conditions. The higher corrosion and tribological performance of NC Ni-Co/CoO graded materials can be attributed to the graded microstructure within the deposits, the anti-corrosion barrier of a dense oxide layer and the solid lubrication effect of CoO-rich tribo-surface films.     

The effect of stacking faults on the electrochemical performance of nickel hydroxide electrodes

The crystal structure of nickel hydroxide comprises of a repetitive stacking of charge neutral layers AbC AbC AbC. A and C denotes the hydroxyl ions which are hexagonally close packed, while b denotes the divalent nickel ions occupying octahedral interstitial sites. The random incorporation of other layers, such as AcB, BaC, CbA, etc., within AbC AbC AbC … stacking sequence can lead to the formation of stacking faults. DIFFaX simulations show that each kind of stacking fault produces a characteristic pattern of non-uniform broadening of the peaks corresponding to the (h 0 ?) reflections in the powder X-ray diffraction (PXRD) pattern of nickel hydroxide. The electrochemical property of each two types of stacking faulted nickel hydroxide is investigated. 2H₂ type of stacking faulted nickel hydroxide delivers better electrochemical activity compared to 3R₂ type stacking faulted nickel hydroxide.     

Fabrication of high performance surface enhanced Raman scattering substrates by a solid-state ionics method

Silver nanostructures were prepared by a solid-state ionics method using fast ionic conductor RbAg(4)I(5) films under a direct current electric field (DCEF). The surface morphology of the silver nanostructures grown under different constant current fields was characterized by scanning electron microscopy (SEM). Rhodamine 6G (R6G) aqueous solutions were used as probe molecules to detect the Raman enhancement performance of the silver nanostructure substrates. The effect of external electric field current intensity on the surface morphology of the silver nanostructures during the preparation was studied in detail. The enhancement effect of the silver nanostructure surface enhanced Raman scattering (SERS) substrates with different surface morphologies toward R6G was determined. We found that disordered silver nanowires (DSNW), ordered silver nanowires (OSNW), densely arranged silver nanobamboo arrays (SNBA) and compactly arranged silver nanobud clusters (SNBC) were respectively obtained when the constant current intensity was 3?μA, 5?μA, 8?μA and 12?μA under the same vacuum evaporation plating conditions. The limiting concentrations of R6G for these SERS substrates were found to be 10(-7)?mol?l(-1), 10(-13)?mol?l(-1), 10(-13)?mol?l(-1) and 10(-16)?mol?l(-1), respectively.     

Fabrication of thermoplastic polyester elastomer/layered zinc hydroxide nitrate nanocomposites with enhanced thermal,mechanical and combustion properties

The objective of this study is to explore the potential of layered zinc hydroxide nitrate modified with sodium benzoate as nanoparticle in thermoplastic polyester elastomer (TPEE). The organically modified zinc hydroxide nitrate was compounded with TPEE using solution blending method. The nanocomposite structure was characterized by means of X-ray diffraction and transmission electron microscopy. The results showed that the nanoparticle was homogenously dispersed in TPEE matrix, and partially exfoliated structure was formed. The thermal behavior, mechanical and thermal combustion properties of the novel nanocomposite were studied respectively through differential scanning calorimeter (DSC), dynamic mechanical analysis (DMA) and microscale combustion calorimeter (MCC). For the nanocomposite containing 7 wt% nanoparticle, the crystallization temperature evaluated by DSC was increased by 10 °C. The storage modulus at −95 °C measured by DMA was improved by around 26%. The heat release capacity (an indicator of a material fire hazard) from MCC testing was reduced by about 56% (compared to the results of neat TPEE).     

Fabrication and performance of a multistrip silicon detector for low energy nuclear experiments

A multistrip silicon detector was fabricated by using planar techniques. It consisted of five parallel pn-junction strips on a wafer of 200 μm thick. The dimension of each strip was 2 mm × 20 mm and the strip pitch was 2.6 mm. The detector was tested by using heavy ions produced in the reaction of ¹⁸¹Ta + ¹⁴N at 210 MeV. We found that it enables clear particle identification for heavy ions and that it shows good property for a position sensitive detector. We studied phenomena of multiple output events induced by a single particle entering the detector; events giving double outputs occurred only in a arrow gap between adjacent strips. Events with more than triple outputs did not exist and insensitive areas were not observed.     

聚乙烯/碱式硫酸镁晶须复合材料的研究

系统研究了碱式硫酸镁晶须(MHSH)对低密度聚乙烯(LDPE)性能的影响.实验结果表明,复合材料的拉伸强度、热氧化稳定性、阻燃性能和热变形温度随着MHSH含量的增加而显著提高.作为增强阻燃无机纤维,MHSH具有广阔的应用前景.     

Amorphous cobalt-iron decorated carbon paper with nanosheet structure for enhanced oxygen evolution reaction

Tremendous attention has been paid on high efficiency, readily available and stability of electrocatalysts. Herein, we ingenious report a one-step reaction strategy synthesis of CoFe/CP grown on three-dimensional (3D) nanoarray carbon paper (CP) containing non-precious metals for oxygen evolution reaction (OER) with low-cost and unique hierarchical porous structure. This amorphous CoFe/CP hybrid exhibits commendable electrocatalytic performance in the OER process, requiring only overpotential of 278 mV to achieve 10 mAcm⁻² in 1.0 M KOH solution and a lower Tafel slope of 49.12 mVdec^-1. In addition, this sample shows a long-term durability even at 200 mAcm⁻² without obvious decay, which attributes to peculiar multistage graded nano structure and the change of composition at the interface of CP. Therefore, the remarkable OER activity can provide a new strategy to construct potential candidates, which will replace the state-of-the-art precious metals for OER in the future.     

沉积钴镀层的球形Ni(OH)2的电性能研究

采用化学度的方法在球形Ni(OH)2表面包覆了金属钴,通过比较恒电流充放电实验和循环伏安实验结果,发现球形Ni(OH)2表面镀钴,可以明显提高电极的放电容量,活性物质利用率,增加电极反应的可逆性,用XRD法比较研究了包覆钴和掺钴球形Ni(OH)2正极在充放电过程中相的生成和变化,发现掺钴的球形Ni(OH)2可抑制γ－ＮiOOH的生成,这有利于提高Ni(OH)2电极的循环寿命。此外,本文还对镀钴层改进Ｎi(OH)2电极性能的机理进行了讨论。     

Chestnut shell-like N-doped carbon coated NiCoP hollow microspheres for hybrid supercapacitors with excellent electrochemical performance

In this work, transition metal phosphides (TMPs) were reinforced by a solvothermal synthesis method and in situ polymerization in dopamine with one-step phosphating and carbonizing process to form chestnut shell-like N-doped carbon coated NiCoP (NiCoP@N-C) hollow microspheres. Excellent morphologic structure is still reflected in NiCoP@N-C, which is suitable for rapid electron and electrolyte transfer. Benefiting from the excellent structure, the coating of N-doped carbon, and the synergistic effect of Ni and Co, NiCoP@N-C reveals excellent electrochemical properties (high specific capacitance of 1660 F·g⁻¹ (830 C·g⁻¹) at 1 A·g⁻¹). In addition, a NiCoP@N-C//carbonization HKUST-1 (HC) achieves high specific energy of 51.8 Wh·kg⁻¹, ultrahigh specific power of 21.63 kW·kg⁻¹, and excellent cycling stability up to 10000 cycles (a capacitance retention of 96.7%). The results show that the NiCoP@N-C electrode material has a wide application in supercapacitors and other energy storage devices.