Synergistic Tuning of Nickel Cobalt Selenide@Nickel Telluride Core-Shell Heteroarchitectures for Boosting Overall Urea Electrooxidation and Electrochemical Supercapattery

Herein,we demonstrate the synthesis of bifunctional nickel cobalt selenide@nickel telluride(Ni_(x)Co_(12-x)Se@NiTe)core-shell heterostructures via an electrodeposition approach for overall urea electrolysis and supercapacitors.The 3D vertically orientated NiTe dendritic frameworks induce the homogeneous nucleation of 2D Ni_(x)Co_(12-x)Se nanosheet arrays along similar crystal directions and bring a strong interfacial binding between the integrated active components.In particular,the optimized Ni_(6)Co_(6)Se@NiTe with an interface coupling effect works in concert to tune the intrinsic activity.It only needs a low overpotential of 1.33 V to yield a current density of 10 mA cm^(-2)for alkaline urea electrolysis.Meanwhile,the full urea catalysis driven only by Ni_(6)Co_(6)Se@NiTe achieves 10 mA cm^(-2)at a potential of 1.38 V and can approach a constant level of the current response for 40 h.Besides,the integrated Ni_(6)Co_(6)Se@NiTe electrode delivers an enhanced specific capacity(223 mA h g^(-1)at 1 A g^(-1))with a high cycling stability.Consequently,a hybrid asymmetric supercapacitor(HASC)device based on Ni_(6)Co_(6)Se@NiTe exhibits a favorable rate capability and reaches a high energy density of 67.7 Wh kg^(-1)and a power density of 724.8 W kg^(-1)with an exceptional capacity retention of 92.4%after sequential 12000 cycles at 5 A g^(-1).

Carbon Nanofibers Containing Ag/TiO₂Composites as a Preliminary Stage for CDI Technology

Silver/titanium dioxide composite nanoparticles imbedded in polyacrylonitrile (PAN) nanofibers and converted into carbon nanofibers by stabilization and calcination was obtained and tested for capacitive deionization technology. First, the silver ions were converted to metallic silver nanoparticles, through reduction of silver nitrate with dilute solution of PAN. Second, the TiO2 precursor (Titanium Isopropoxide) was added to the solution to form Ag/TiO2 composites imbedded in the PAN polymer solution. Last step involves electrospinning of viscous PAN solution containing silver/TiO2 nanoparticles, thus obtaining PAN nanofibers containing silver/TiO2 nanoparticles. Scanning electron microscopy (SEM) revealed that the diameter of the nanofibers ranged between 50 and 300 nm. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) showed silver/TiO2 nanoparticles dispersed on the surface of the carbon nanofibers. The obtained fiber was fully characterized by measuring and comparing the FTIR spectra and thermogravimetric analysis (TGA) diagrams of PAN nanofiber with and without imbedded nanoparticles, in order to show the effect of silver/TiO2 nanoparticles on the electrospun fiber properties.

Fabrication of PMMA nanocomposite biomaterials reinforced by cellulose nanocrystals extracted from rice husk for dental applications

The primary objective of global studies is to develop the properties and durability of polymers for various applications.When it comes to dental disability,denture base materials must have sufficient mechanical and tribological performance in order to withstand the forces experienced in the mouth.This work aims to investigate the effects of the addition of low content of cellulose nanocrystals(CNC)on the mechanical and tribological performance of the polymethyl methacrylate(PMMA)nanocomposites.Different weight percent of CNC(0,0.2,0.4,0.6,and 0.8 wt%)were added to the PMMA matrix followed by ball milling to evenly distribute the nanoparticles reinforced phase in the matrix phase.The findings emphasize the significant impact of CNC integration on the performance of PMMA nanocomposites.By increasing the content of the CNC nanoparticles,the mechanical properties of PMMA were improved.In addition,the tribological outcomes demonstrated a significant reduction in the friction coefficient besides an enhancement in the wear resistance as the weight percentage of nanoparticles increased.The surface of the worn samples was investigated by utilizing SEM to identify the wear mechanisms corresponding to the different compositions.In addition,a finite elment model(FEM)was developed to ascertain the thickness of the worn layer and the generated stressed on the surfaces of the nanocomposite throughout the friction process.

In situ silver clusters decorated Bi_(24)O_(31)Cl_(10)nanorods for boosting photo-thermal catalytic activities

High photogenerated carrier recombination rate and weak spectral response are the two main factors restricting photocatalytic activities of photocatalysts.In this work,a novel Ag/Bi_(24)O_(31)Cl_(10)heterojunction has been developed by the in-situ photoreduction technique to address the preceding issues.Physico-chemical properties of as-synthesized 0.7 wt%Ag/Bi_(24)O_(31)Cl_(10)photocatalysts were investigated in detail.The Ag clusters can be seen as surface plasmon polaritons to light absorption capacity and photothermal effect,which was demonstrated via Raman and UV-Vis diffuse reflectance spectra(UV-Vis DRS).Den-sity functional theory(DFT)calculations show that the additional unoccupied crystal orbital by the silver(Ag)will accelerate the charge separation where some of the excited electrons to the conduction band of Bi_(24)O_(31)Cl_(10)will drift to these orbitals which in turn prevent charge recombination.Therefore,Ag metal cluster-decorated Bi_(24)O_(31)Cl_(10)photocatalysts can be identified as electron trappers to boost the spatial separation of the photogenerated carrier,and finally,the CH 4 generation rate and the rhodamine b(RhB)degraded efficiency of Ag/Bi_(24)O_(31)Cl_(10)photocatalysts are enhanced about 1.54 and 5.20 times,respectively.The Ag/Bi_(24)O_(31)Cl_(10)composite photocatalyst retained high photocatalytic activities after four cycles indi-cating the stability and repeatability of the Ag/Bi_(24)O_(31)Cl_(10)composite.This work aims to provide new insight into modifying ideal semiconductor materials for high photocatalytic activity.