Conducting Polymer-Based e-Refinery for Sustainable Hydrogen Peroxide Production

Electrocatalysis enables the industrial transition to sustainable production of chemicals using abundant precursors and electricity from renewable sources.De-centralized production of hydrogen peroxide(H_(2)O_(2))from water and oxygen of air is highly desirable for daily life and industry.We report an effective electrochemical refinery(e-refinery)for H_(2)O_(2)by means of electrocatalysis-controlled comproportionation reaction(2_(H)O+o→2HO),feeding pure water and oxygen only.Mesoporous nickel(Ⅱ)oxide(NiO)was used as electrocatalyst for oxygen evolution reaction(OER),producing oxygen at the anode.Conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(PEDOT:PSS)drove the oxygen reduction reaction(ORR),forming H_(2)O_(2)on the cathode.The reactions were evaluated in both half-cell and device configurations.The performance of the H_(2)O_(2)e-refinery,assembled on anion-exchange solid electrolyte and fed with pure water,was limited by the unbalanced ionic transport.Optimization of the operation conditions allowed a conversion efficiency of 80%.

Understanding the catalysis of chromium trioxide added magnesium hydride for hydrogen storage and Li ion battery applications

This study explores how the chemical interaction between magnesium hydride(MgH_(2))and the additive CrO_(3) influences the hydrogen/lithium storage characteristics of MgH_(2).We have observed that a 5 wt.%CrO_(3) additive reduces the dehydrogenation activation energy of MgH_(2) by 68 kJ/mol and lowers the required dehydrogenation temperature by 80℃.CrO_(3) added MgH_(2) was also tested as an anode in an Li ion battery,and it is possible to deliver over 90%of the total theoretical capacity(2038 mAh/g).Evidence for improved reversibility in the battery reaction is found only after the incorporation of additives with MgH_(2).In depth characterization study by X-ray diffraction(XRD)technique provides convincing evidence that the CrO_(3) additive interacts with MgH_(2) and produces Cr/MgO byproducts.Gibbs free energy analyses confirm the thermodynamic feasibility of conversion from MgH_(2)/CrO_(3) to MgO/Cr,which is well supported by the identification of Cr(0)in the powder by X ray photoelectron spectroscopy(XPS)technique.Through high resolution transmission electron microscopy(HRTEM)and energy dispersive spectroscopy(EDS)we found evidence for the presence of 5 nm size Cr nanocrystals on the surface of MgO rock salt nanoparticles.There is also convincing ground to consider that MgO rock salt accommodates Cr in the lattice.These observations support the argument that creation of active metal–metal dissolved rock salt oxide interface may be vital for improving the reactivity of MgH_(2),both for the improved storage of hydrogen and lithium.

Calculating the Crystallite Size of Microsorum scolopendria AgCl Nanoparticles and Their Biological Activities

In this work, AgCl nanoparticles were synthesized from Microsorum scolopendria (MS) aqueous extract and AgNO3 solution. Preliminary confirmation was a color change from a light brown to a dark-colored solution and a UV-Vis spectra surface plasmon resonance peak at 427 nm. Measured vibrational frequencies at 1713 cm1 and 1030 cm1 for C-O stretching of carboxylic acid or aliphatic ketone, and 1547 cm1 for possibly N-O stretching of nitro compounds by Infrared (FTIR) analysis explain the possible biomaterial electronegative species or functional groups responsible for the reduction of Ag ( 1) to Ag (0) for the formation of MS-AgCl nanoparticles. XRD analysis studies revealed that these particles contained face-centered cubic crystallites of metallic AgCl of 100 % with an average calculated crystallite size range of 30.34 nm (SD = 5.10 nm) by Scherrers equation and a calculated crystallite size of 66.04 nm with a lattice strain of 0.00175 nm by Williamson Hall equation. The measured albumin denaturing activity of MS-AgCl nanoparticles gave an IC50 value of 26.70 g/mL and 1.35 g/mL for the positive control diclofenac. Additionally, the measured ability of phosphomolybdate complex formation, the antioxidant IC value of MS-AgCl nanoparticles was 35.29 g/mL, and positive control ascorbic acid was 13.91 g/mL. In all, using MS fern frond aqueous extracts, this preliminary work confirms MS-AgCl nanoparticles as potential therapeutic agents for oxidative stress, inflammatory problems, and related diseases.

Recent research progress on magnesium alloys in Korea:A review

This review highlights the recent advancements in Mg research in South Korea with a prime focus on high-speed-extrudable Mg–Bi-based alloys for high productivity and strength, innovative techniques utilizing {10–12} twinning for improved mechanical properties, and alloying and processing methods for enhanced corrosion resistance. High-alloyed Mg–Bi-based alloys possess thermally stable α-Mg matrix and secondary phase, which ensures high-speed extrusion of these alloys at elevated temperatures without hot cracking. Consequently, they exhibit outstanding extrudability with a maximum extrusion speed of up to 70 m/min. Furthermore, their high alloying contents offer excellent strength even after high-speed extrusion through strong solid solution hardening and particle hardening effects, making them suitable for high-performance extruded Mg products. The pre-twinning process utilizing {10–12} twinning and the combined process of pre-twinning and subsequent annealing have shown promise in controlling microstructure and texture of wrought Mg alloys and thus enhancing their mechanical properties. The pre-twinning process enhances tensile strength, fatigue properties, and age-hardening rate of Mg alloys. Furthermore, the combined processes of pre-twinning and subsequent annealing considerably improve their ductility, stretch formability, bending formability,and damping capacity. Efforts have been made to improve the corrosion resistance of Mg alloys through alloying additions, process treatments,and surface coatings. Alloying elements like Ca, Sc, and Sm alter the microstructural features(such as secondary phases and grain size)that affect the corrosion phenomenon. Process treatments such as multidirectional forging, screw rolling, and pulse electron beam can also improve the corrosion resistance by refining the microstructure. Furthermore, advanced surface coating technologies can create durable and corrosion-resistant layers for effectively protecting the Mg alloys. All these research activities conducted in South Korea have considerably contributed to the widespread utilization of Mg alloys in diverse applications by overcoming the inherent limitations of Mg alloys such as low extrudability, formability, and corrosion resistance.

Effects of temperature on critical resolved shear stresses of slip and twining in Mg single crystal via experimental and crystal plasticity modeling

Magnesium(Mg)single crystal specimens with three different orientations were prepared and tested from room temperature to 733 K in order to systematically evaluate effects of temperature on the critical resolved shear stress(CRSS)of slips and twinning in Mg single crystals.The duplex non-basal slip took place in the temperature range from 613 to 733 K when the single crystal samples were stretched along the<0110>direction.In contrast,the single basal slip and prismatic slip were mainly activated in the temperature range from RT to 733 K when the tensile directions were inclined at an angle of 45°with the basal and the prismatic plane,respectively.Viscoplastic self-consistent(VPSC)crystal modeling simulations with genetic algorithm code(GA-code)were carried out to obtain the best fitted CRSSs of major deformation modes,such as basal slip,prismatic slip,pyramidalⅡ,{1012}tensile twinning and{1011}compressive twinning when duplex slips accommodated deformation.Additionally,CRSSs of the basal and the prismatic slip were derived using the Schmid factor(SF)criterion when the single slip mainly accommodated deformation.From the CRSSs of major deformation modes obtained by the VPSC simulations and the SF calculations,the CRSSs for basal slip and{1012}tensile twinning were found to show a weak temperature dependence,whereas those for prismatic,slip and{1011}compressive twinning exhibited a strong temperature dependence.From the comparison of previous results,VPSC-GA modeling was proved to be an effective method to obtain the CRSSs of various deformation modes of Mg and its alloys.

Cascade excitation of vortex motion and reentrant superconductivity in flexible Nb thin films

High quality Nb films were successfully prepared on both flexible polyimide(PI)and rigid Al2O3substrates and their transport properties were systematically studied at various applied currents,external magnetic fields,and sample orientations.It is found that a curved Nb/PI film exhibits quite different superconducting transition and vortex dynamics compared to the flat Nb/Al2O3film.For the curved Nb/PI film,smooth superconducting transitions were obtained at low currents,while unexpected cascade structures were revealed in theρ(T)curves at high currents.We attribute this phenomenon to the gradient distribution of vortex density together with a variation of superconductivity along the curved film.In addition,reentrant superconductivity was induced in the curved Nb/PI thin film by properly choosing the measurement conditions.We attribute this effect to the vortex pinning from both in-plane vortices and out-of-plane vortices.This work reveals the complex transport properties of curved superconducting thin films,providing important insights for further theoretical investigations and practical developments of flexible superconductors.

Hydrophobic silica nanoparticle-stabilized invert emulsion as drilling fluid for deep drilling

An oil-based drilling fluid should be stable and tolerant to high temperatures for use in deep drilling. An invert emulsion of water in oil is a good choice as an oil- based drilling fluid which is a mixture of a solid phase and two immiscible liquid phases stabilized by a polymeric surfactant. In deep drilling, due to high temperatures, the polymeric surfactant degrades and a phase separation occurs. Here, octadecyltrimethoxysilane-modified silica nanoparticles were used to form a stable invert emulsion of water in oil for the drilling fluid model which resulted in a milky fluid with the formation of 60 gm water droplets. In addition, rheological study showed that using hydrophobic silica nanoparticles resulted in a stable water in oil invert emulsion with desired properties for a drilling fluid that can be modified by adjusting the nanoparticle nature and content. Aging experiments at 120 ℃ indicated that they also have good stability at high temperatures for challenging drilling operations.

Nanotechnology applications for the therapy of liver fibrosis

Chronic liver diseases represent a major global health problem both for their high prevalence worldwide and,in the more advanced stages,for the limited available curative treatment options.In fact,when lesions of different etiologies chronically affect the liver,triggering the fibrogenesis mechanisms,damage has already occurred and the progression of fibrosis will have a major clinical impact entailing severe complications,expensive treatments and death in end-stage liver disease.Despite significant advances in the understanding of the mechanisms of liver fibrinogenesis,the drugs used in liver fibrosis treatment still have a limited therapeutic effect.Many drugs showing potent antifibrotic activities in vitro often exhibit only minor effects in vivo because insufficient concentrations accumulate around the target cell and adverse effects result as other non-target cells are affected.Hepatic stellate cells play a critical role in liver fibrogenesis,thus they are the target cells of antifibrotic therapy.The application of nanoparticles has emerged as a rapidly evolving area for the safe delivery of various therapeutic agents(including drugs and nucleic acid)in the treatment of various pathologies,including liver disease.In this review,we give an overview of the various nanotechnology approaches used in the treatment of liver fibrosis.

Effects of small additions of Zn on the microstructure, mechanical properties and corrosion resistance of WE43B Mg alloys

Zn is a commonly used alloying element for Mg alloys owing to its beneficial effects on mechanical properties. To improve the mechanical and corrosion properties of WE43B Mg alloys, the effects of 0–0.7wt% Zn addition on the microstructure and properties of sample alloys were investigated. Addition of Zn to as-cast WE43B alloy promoted the formation of the Mg12Nd phase;by contrast, after T6 heat treatment, the phase composition of WE43B alloys with and without Zn addition remained mostly the same. A long-period stacking ordered phase was predicted by CALPHAD calculation, but this phase was not observed in either the as-cast or heat-treated Zn-containing WE43B alloys. The optimum temperature and duration of T6 heat treatment were obtained using CALPHAD calculations and hardness measurements. Addition of Zn resulted in a slight reduction in the average grain size of the as-cast and T6 heat-treated WE43B alloys and endowed them with increased corrosion resistance with little effect on their mechanical properties.

Microstructure and mechanical and corrosion properties of hot-extruded Mg–Zn–Ca–(Mn)biodegradable alloys

Biodegradable Mg-based implants are widely used in clinical applications because they exhibit mechanical properties comparable to those of human bone and require no revision surgery for their removal.Among Mg-based alloys,Mg–Zn–Ca–(Mn)alloys have been extensively investigated for medical applications because the constituent elements of these alloys,Mg,Zn,Ca,and Mn,are present in human tissues as nutrient elements.In this study,we investigated the effect of the hot extrusion temperature on the microstructure,mechanical properties,and biodegradation rate of Mg–Zn–Ca–(Mn)alloys.The results showed that the addition of Mn and a decrease in the extrusion temperature resulted in grain refinement followed by an increase in the strength and a decrease in the elongation at fracture of the alloys.The alloys showed different mechanical properties along the directions parallel and perpendicular to the extrusion direction.The corrosion test of the alloys in the Hanks’solution revealed that the addition of Mn significantly reduced the corrosion rate of the alloys.The Mg–2 wt%Zn–0.7 wt%Ca–1 wt%Mn alloy hot-extruded at 300℃ with an ultimate tensile strength of 278MPa,an yield strength of 229MPa,an elongation at fracture of 10%,and a corrosion rate of 0.3 mm/year was found to be suitable for orthopedic implants.

SMFs-supported Pd nanocatalysts in selective acetylene hydrogenation:Pore structure-dependent deactivation mechanism

In the present study,CNFs,ZnO and Al2O3 were deposited on the SMFs panels to investigate the deactivation mechanism of Pd-based catalysts in selective acetylene hydrogenation reaction.The examined supports were characterized by SEM,NH3-TPD and N2adsorption-desorption isotherms to indicate their intrinsic characteristics.Furthermore,in order to understand the mechanism of deactivation,the resulted green oil was characterized using FTIR and SIM DIS.FTIR results confirmed the presence of more unsaturated constituents and then,more branched hydrocarbons formed upon the reaction over alumina-supported catalyst in comparison with the ones supported on CNFs and ZnO,which in turn,could block the pores mouths.Besides the limited hydrogen transfer,N2 adsorption-desorption isotherms results supported that the lowest pore diameters of Al2O3/SMFs close to the surface led to fast deactivation,compared with the other catalysts,especially at higher temperatures.

Oxidative coupling of methane over (Na_2WO_4+Mn or Ce)/SiO_2 catalysts:In situ measurement of electrical conductivity

The effects of manganese oxide or ceria promoters on the performance of Na2WO4/SiO2 catalysts for oxidative coupling of methane （OCM） are reported. The OCM reaction was performed in a continuous-flow microreactor at 800℃, atmospheric pressure and under GHSV = 13200 ml·gCat^-1·h^-1.Catalysts were characterized by in situ conductivity measurement, FT-IR spectroscopy, XRD, SEM and temperature programmed reduction analysis. Manganese oxide promoted Na2WO4/SiO2 is considered as one of the active and selective catalysts for OCM reaction. Ceria with high oxygen storage capacity is selected as a proper oxygen activator, providing a higher concentration of the oxy-anion species which is suitable for OCM reaction and compared with manganese oxide. Electrical conductivity of the catalysts was measured in OCM reaction under oxidizing atmosphere, i.e. in the absence of methane. It was found that the trimetallic catalysts, i.e. the catalysts having sodium, tungsten and Mn or Ce species, exhibited similar crystalline structures and morphologies, which lead to suitable bulk properties for the formation of an active and selective catalyst. However, tungsten had significant effect on the texture and redox properties of the catalysts. It was also shown that the crystalline structure of the bimetallic （Na＋Mn or Ce）/SiO2 samples was quite different. This reveals that the metal oxides have significant effect on the extent of crystallization, taking place in the course of interaction of sodium with silica support. Similar conductivities and catalytic performances of （Na2WO4＋Mn or Ce）/SiO2 catalysts propose that the ability of Na2WO4/SiO2 for utilizing oxy-anions formed in presence of different metal oxides is limited.

Ni/TiO_2-SiO_2上光催化重整葡萄糖以低CO选择性制H_2(英文)

Nano-sized Ni particles on TiO2-SiO2 were synthesized by the two methods of photo-assisted deposition(PAD) and impregnation.H2,which is a promising energy carrier,with a low CO concentration was produced by the photocatalytic reforming of glucose(a model biomass) on the Ni/TiO2-SiO2 catalyst.The supported Ni enhanced the rate of H2 production while it suppressed CO selectivity.The catalysts were characterized by X-ray diffraction,X-ray absorption fine structure,transmission electron microscope,and nitrogen adsorption analysis.Both H2 production and CO selectivity were strongly dependent on the preparation method,and PAD-Ni/TiO2-SiO2 was the better catalyst for H2 production with the lowest CO concentration.

Gallium-containing magnesium alloy for potential use as temporary implants in osteosynthesis

In recent years magnesium alloys have been studied intensively with a view to their potential use in bioresorbable medical implants.In the present work the microstructure and the corrosion properties of a new bioresorbable Mg-4 wt%Ga-4 wt%Zn alloy and its variants with low Ca,Nd or Y additions were investigated.These alloys are of interest due to the efficacy of gallium as an element inhibiting bone resorption,osteoporosis,Paget's disease,and other illnesses.A severe plastic deformation technique of equal channel angular pressing(ECAP)was shown to provide the alloys with favorable mechanical properties.In addition,a desirable low rate of degradation in a simulated body fluid(Hanks'solution)was achieved.

Oxidation of chalcopyrite in air-equilibrated acidic solution: Inhibition with phenacyl derivatives

The effects of 4-(2-hydroxyphenyl)-2-(morpholin-4-yl)-1,3-thiazole(Pr02), 1-(3,5-dibromo-2-hydroxyphenyl)-1-oxoethan-2-yl-N,N-diethyldithiocarbamate(Pr04) and 1-(5-bromo-2-hydroxy-3-methylphenyl)-1-oxoethan-2-yl-Oethyl xanthate(Pr06) on the aqueous oxidation of chalcopyrite(CuFeS2) in air-equilibrated solution at a temperature of 25 ℃ and a pH of 2.5 were studied. The effects were investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy(EIS), scanning electron microscopy coupled with energy dispersive X-ray(SEM/EDX) analysis, aqueous batch experiments, Fourier transform infrared(FTIR) spectroscopy, Raman scattering and quantum chemical calculations. It is found that the anodic current densities decrease in the order of EtOH > Pr02 > Pr04 > Pr06. These results, along with those of the EIS measurements, show that Pr02, Pr04 and Pr06 are effective anodic inhibitors of chalcopyrite aqueous oxidation. Both Raman scattering and FTIR spectroscopy indicate that the elemental sulfur, polysulfide and ferric oxyhydroxides that form on the surface of the mineral are not responsible when it comes to the aqueous oxidation inhibition of chalcopyrite. Quantum chemical calculations show that the adsorption of the tested compounds on the chalcopyrite surface is energetically favorable and so, it can explain the inhibiting effects that were observed.

Distinction between critical current effects and intrinsic anomalies in the point-contact Andreev reflection spectra of unconventional superconductors

In this work,we discuss the origin of several anomalies present in the point-contact Andreev reflection spectra of（Li1-xFex）OHFeSe,LiTi2O4,and La2-xCexCuO4.While these features are similar to those stemming from intrinsic superconducting properties,such as Andreev reflection,electron-boson coupling,multigap superconductivity,d-wave and p-wave pairing symmetry,they cannot be accounted for by the modified Blonder–Tinkham–Klapwijk（BTK） model,but require to consider critical current effects arising from the junction geometry.Our results point to the importance of tracking the evolution of the dips and peaks in the differential conductance as a function of the bias voltage,in order to correctly deduce the properties of the superconducting state.

Two-dimensional multimetallic sulfide nanosheets with multi-active sites to enhance polysulfide redox reactions in liquid Li2S6-based lithium-polysulfide batteries

The lithium-sulfur battery has attracted enormous attention as being one of the most significant energy storage technologies due to its high energy density and cost-effectiveness.However,the "shuttle effect" of polysulfide intermediates represents a formidable challenge towards its wide applications.Herein,we have designed and synthesized two-dimensional Cu,Zn and Sn-based multimetallic sulfide nanosheets to construct multi-active sites for the immobilization and entrapment of polysulfides with offering better performance in liquid Li2S6-based lithium-polysulfide batteries.Both experimental measurements and theoretical computations demonstrate that the interfacial multi-active sites of multimetallic sulfides not only accelerate the multi-chained redox reactions of highly diffusible polysulfides,but also strengthen affinities toward polysulfides.By adopting multimetallic sulfide nanosheets as the sulfur host,the liquid Li2 S6-based cell exhibits an impressive rate capability with 1200 mAh/g and retains 580 mAh/g at 0.5 mA/cm^(2) after 1000 cycles.With high sulfur mass loading conditions,the cell with 2.0 mg/cm^(2) sulfur loading delivers a cell capacity of 1068 mAh/g and maintains 480 mAh/g with 0.8 mA/cm^(2) and 500 cycles.This study provides new insights into the multifunctional material design with multi-active sites for elevated lithium-polysulfide batteries.

Feasible design for electricity generation from Chlorella vulgaris using convenient photosynthetic conditions

Many recent studies are concerned with low cost,easy to handle and alternative renewable energy as a feasible solution for the upcoming crisis of energy shortage.Microalgae are unicellular entities the can only depend on CO_(2),water and solar power to cover their nutritional needs.The current study is concerned with using algal cells in a polymeric hydrogel,as a cheap source of energy for electricity generation.Chlorella vulgaris has been proved to be a promising algal species for electricity generation,as compared with Micractinium reisseri.PVA hydrogel has been used for the immobilization of both algal species in order to protect them from the adverse surrounding conditions in addition to its ability to slowly release the required water molecules according to needs.Under these conditions,C.vulgaris showed the ability to generate 60 mV compared with 15 mV generated by M.reisseri.Scanning electron micrographs showed nano-threads that bind the C.vulgaris cells to each other,indicating the ability of algae to create nanowires that facilitate the electron transfer among algal cells and from cells to the nearest electrode.However,we would expect an increase in the produced potential with simultaneous amendment of environmentally polluted water,such as sewage or waste water.Both of FTIR and raman spectroscopy proved the presence of the characteristic groups of PVA hydrogel and proved the proper integration of the algal cells inside the hydrogel cavities.

Hydrothermal preparation of TiO_(2)-Ag nanoparticles and its antimicrobial performance against human pathogenic microbial cells in water

Water contaminated with pathogenic microbes is considered as one of the most common routes for transmitting diseases in human beings.Different methods have been applied for the decontamination of microbes in contaminated water.In the current study,an easy to do hydrothermal method has been used for the preparation of TiO_(2)-Ag nanoparticles.The obtained material was characterised using a scanning electron microscope(SEM)and fourier transform infra-red spectroscopy(FTIR).The morphological appearance of the obtained nanoparticles was in the shape of a sphere with a size range of 60-90 nm.The antimicrobial activity of the prepared nanoparticles was tested against several pathogenic bacteria and fungi.The obtained results proved that the nanoparticles succeeded to affect all the tested microbes in the following order:Bacillus cereus ATCC6633>Pseudomonas aeruginosa ATCC9027=Klebsiella pneumoniae ATCC13883>Vibrio cholera ATCC700=Candida albicans ATCC 700=Escherichia coli NCTC10418>Staphylococcus aureus ATCC6538.The minimum inhibitory concentration(MIC)of the prepared nanoparticles varied among the tested microbes at range of 12 mg/ml and 25 mg/ml.These results encourage the application of prepared TiO_(2)-Ag nanoparticles for treatment of microbe-contaminated waters.

Triple-phase interfaces of graphene-like carbon clusters on antimony trisulfide nanowires enable high-loading and long-lasting liquid Li_(2)S_(6)-based lithium-sulfur batteries

High performance of lithium-sulfur batteries have been dragged down by their shuttling behavior which is complicated multiphase transition-based 16-electron redox reactions of the S8/Li2 S.In this article,the triple-phase interfaces of graphene-like carbon clusters on antimony trisulfide(C-Sb_(2)S_(3))nanowires are tailored to design a multifunctional polysulfide host which can inhibit migration of polysulfides and accelerate conversion kinetics of redox electrochemical reactions.Benefiting from the triple-interface design of polysulfides/Sb_(2)S_(3)/carbon clusters,the C-Sb_(2)S_(3) electrode not only anchors polysulfide migration by the synergistic effect of Sb,S,and C atoms as interfacial active sites,but also the graphene-like carbon clusters shorten the diffusion paths to further favor redox electron/ion transport through the liquid(electrolyte/polysulfide)and solid(Li2 S/S8,carbon clusters,and Sb_(2)S_(3))-based triple-phases.Therefore,these Li_(2)S_(6)-based C-Sb_(2)S_(3) cells possess high sulfur loading,excellent cycling stability,impressive specific capacity,and great rate capability.This work of interfacial engineering reveals insight for powering reaction kinetics in the complicated multistep catalysis reaction with multiphase evolution-based chargetransfer/non-transfer processes.