Vastly Synergistic Fe_(2)CuNiS_(4)-Nanoarchitectures Anchored 2D-Nano-Sandwich Derived from Flower-Like-CuFeS_(2)/N-Graphene and Cube-Like-NiFeS_(2)/N-CNTs for Water Oxidation and Nitrophenol Reduction

Surface area,pore properties,synergistic behavior,homogenous dispersion,and interactions between carbon matrix and metal-nanostructures are the key factors for achieving the better performance of carbon-metal based(electro)catalysts.However,the traditional hydro-or solvothermal preparation of(electro)catalysts,particularly,bi-or tri-metallic nanostructures anchored graphene(G)or carbon nanotubes(CNTs),often pose to poor metal–support interaction,low synergism,and patchy dispersion.At first,bimetallic flower-like-CuFeS_(2)/NG and cube-like-NiFeS_(2)/NCNTs nanocomposites were prepared by solvothermal method.The resultant bimetallic nanocomposites were employed to derive the 2D-nano-sandwiched Fe_(2)CuNiS_(4)/NGCNTs-SW(electro)catalyst by a very simple and green urea-mediated“mix-heat”method.The desired physicochemical properties of Fe_(2)CuNiS_(4)/NGCNTs-SW such as multiple active sites,strong metal-support interaction,homogenous dispersion and enhanced surface area were confirmed by various microscopic and spectroscopic techniques.To the best of our knowledge,this is the first urea-mediated“mix-heat”method for preparing 2D-nano-sandwiched carbon-metal-based(electro)catalysts.The Fe_(2)CuNiS_(4)/NGCNTs-SW was found to be highly effective for alkaline-mediated oxygen evolution reaction at low onset potential of 284.24 mV,and the stable current density of 10 mA cm^(−2) in 1.0 m KOH for 10 h.Further,the Fe_(2)CuNiS_(4)/NGCNTs-SW demonstrated excellent catalytic activity in the reduction of 4-nitrophenol with good kapp value of 87.71×10^(−2)s^(-1)and excellent reusability over five cycles.Overall,the developed urea-mediated“mix-heat”method is highly efficient for the preparation of metal-nanoarchitectures anchored 2D-nano-sandwiched(electro)catalysts with high synergism,uniform dispersion and excellent metal-support interaction.

Nitrogen-and Oxygen-Containing Porous Ultrafine Carbon Nanofiber:A Highly Flexible Electrode Material for Supercapacitor

Herein, we report a simple and effective preparation of ultrafine CNFs （u-CNFs） with high surface area via electrospinning of two immiscible polymers [polyacrylonitrile （PAN） and poly（methyl methacry- late） （PMMA）] followed by calcination at high temperature in an inert atmosphere. Various electrospinning conditions were optimized in detail. Four different kinds of PAN/PMMA ratios （10/0, 7：3, 5：5 and 3：7） were chosen and found that the PAN/PMMA ratio of 3：7 （PAN/PMMA-3：7） is the optimum one. BET anal- ysis showed the specific surface area of the u-CNFs-3：7 was 46Z57 m2/g with an excellent pore volume （1.15 cms g-l） and an average pore size （9.48 nm）： it is about 25 times higher than the conventional CNFs （c-CNFs）. TEM and FE-SEM images confirmed the ultrafine structure of the CNFs with a thinner fiber di- ameter of-50 nm. The graphitic nature and atomic arrangement of the u-CNFs were investigated by Raman and XPS analyses. For the supercapacitor application, unlike the common electrode preparation methods, the u-CNFs-3：7 was used without any activation, chemical or mechanical modifications. The u-CNFs- 3：7 showed a better specific capacitance of 86 Fig in 1 mol/L 1-12S04 when compared to pure CNFs. The excellent physicochemical properties make the u-CNFs-3：7 an alternative choice to the existing CNFs for the supercapacitors.

A Simple Method for the Fabrication of Metallic Copper NanospheresDecorated Cellulose Nanofiber Composite

Herein, we report a new and simple method for the preparation of metallic copper nanospheres- decorated cellulose nanofiber composite （CuNSsJCNFs）. Initially, the cellulose acetate nanofibers （CANFs） were electrospun followed by deacetylation and anionization to produce functional anionic cellulose nanofibers ff-CNFs）. The CuCl2 precursor was deposited on thef-CNFs （CuC12/CNFs） by a simple dipping method. Then the CuCIdCNFs were reduced under vacuum by using aluminum foil to produce the CuNSs/ CNFs. The resultant CuNSs/CNFs composite was characterized by various microscopic and spectroscopic methods. Fourier transform infrared spectroscopy （FT-IR） confirmed the successful functionalization of anionic groups with the CNFs. The field emission scanning electron microscopy （FE-SEM） and transmission electron microscope （TEM） results confirmed the formation of CuNSs on the surface of CNFs. From the scanning electron microscopy-energy dispersive spectroscopy （SEM-EDS） analysis, the weight percentage of Cu was found to be 23.5 wt%. The successful reduction of CuO to metallic Cu was confirmed by X-ray photoemission spectroscopy （XPS） and X-ray diffraction （XRD） analyses. Mechanism has been proposed for the formation of metallic Cu sphere on CNFs.