Novel Perovskite Oxide Hybrid Nanofibers Embedded with Nanocatalysts for Highly Efficient and Durable Electrodes in Direct CO_(2) Electrolysis

The unique characteristics of nanofibers in rational electrode design enable effec-tive utilization and maximizing material properties for achieving highly efficient and sustainable CO_(2) reduction reactions( CO_(2)RRs)in solid oxide elec-trolysis cells(SOECs).However,practical appli-cation of nanofiber-based electrodes faces chal-lenges in establishing sufficient interfacial contact and adhesion with the dense electrolyte.To tackle this challenge,a novel hybrid nanofiber electrode,La_(0.6)Sr_(0.4)Co_(0.15)Fe_(0.8)Pd_(0.05)O_(3-δ)(H-LSCFP),is developed by strategically incorporating low aspect ratio crushed LSCFP nanofibers into the excess porous interspace of a high aspect ratio LSCFP nanofiber framework synthesized via electrospinning technique.After consecutive treatment in 100% H_(2) and CO_(2) at 700°C,LSCFP nanofibers form a perovskite phase with in situ exsolved Co metal nanocatalysts and a high concentration of oxygen species on the surface,enhancing CO_(2) adsorption.The SOEC with the H-LSCFP electrode yielded an outstanding current density of 2.2 A cm^(-2) in CO_(2) at 800°C and 1.5 V,setting a new benchmark among reported nanofiber-based electrodes.Digital twinning of the H-LSCFP reveals improved contact adhesion and increased reaction sites for CO_(2)RR.The present work demonstrates a highly catalytically active and robust nanofiber-based fuel electrode with a hybrid structure,paving the way for further advancements and nanofiber applications in CO_(2)-SOECs.

Recent advances and influencing parameters in developing electrode materials for symmetrical solid oxide fuel cells

This article delivers a robust overview of potential electrode materials for use in symmetrical solid oxide fuel cells(S-SOFCs),a relatively new SOFC technology.To this end,this article provides a comprehensive review of recent advances and progress in electrode materials for S-SOFC,discussing both the selection of materials and the challenges that come with making that choice.This article discussed the relevant factors involved in developing electrodes with nano/microstructure.Nanocomposites,e.g.,non-cobalt and lithiated materials,are only a few of the electrode types now being researched.Furthermore,the phase structure and microstructure of the produced materials are heavily influenced by the synthesis procedure.Insights into the possibilities and difficulties of the material are discussed.To achieve the desired microstructural features,this article focuses on a synthesis technique that is either the most recent or a better iteration of an existing process.The portion of this analysis that addresses the risks associated with manufacturing and the challenges posed by materials when fabricating S-SOFCs is the most critical.This article also provides important and useful recommendations for the strategic design of electrode materials researchers.

High performance and stability of double perovskite-type oxide NdBa0.5Ca0.5Co1.5Fe0.5O5+δas an oxygen electrode for reversible solid oxide electrochemical cell

In this study,we successfully synthesized double perovskite-type oxide NdBa0.5Ca0.5Co1.5Fe0.5O5+δ(NBCCF)using a conventional wet chemical method as the oxygen electrode for reversible solid oxide electrochemical cells(RSOCs).The polarization resistance(Rp)of the composite electrode NBCCFGd0.1Ce0.9O2(GDC)is only 0.079Ωcm^2 at 800℃under air.The single cell based on NBCCF-GDC electrode displays a peak power density of 0.941 W/cm^2 in fuel cell mode and a low Rp value of 0.134Ωcm^2.In electrolysis cell mode,the cell displays an outstanding oxygen evolution reaction(OER)activity and shows current density as high as 0.92 A/cm^2 with 50 vol%AH(Absolute Humidity)at 800℃and applied voltage of 1.3 V.Most importantly,the cell exhibits admirable durability of 60 h both in electrolysis mode and fuel cell mode with distinguished reversibility.All these results suggest that NBCCF is a promising candidate electrode for RSOC.

TUNGSTEN ELECTRODES CONTAINING THREE TYPES OF RARE EARTH OXIDES

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Functionalized graphene oxide-reinforced electrospun carbon nanofibers as ultrathin supercapacitor electrode

Graphene oxide has been used widely as a starting precursor for applications that cater to the needs of tunable graphene. However, the hydrophilic characteristic limits their application, especially in a hydrophobic condition. Herein, a novel non-covalent surface modification approach towards graphene oxide was conducted via a UV-induced photo-polymerization technique that involves two major routes; a UV-sensitive initiator embedded via pi-pi interactions on the graphene planar rings, and the polymerization of hydrophobic polymeric chains along the surface. The functionalized graphene oxide successfully achieved the desired hydrophobicity as it displayed the characteristic of being readily dissolved in organic solvent. Upon its addition into a polymeric solution and subjected to an electrospinning process,non-woven random nanofibers embedded with graphene oxide sheets were obtained. The prepared polymeric nanofibers were subjected to two-step thermal treatments that eventually converted the polymeric chains into a carbon-rich conductive structure. A unique morphology was observed upon the addition of the functionalized graphene oxide, whereby the sheets were embedded and intercalated within the carbon nanofibers and formed a continuous structure. This reinforcement effectively enhanced the electrochemical performance of the carbon nanofibers by recording a specific capacitance of up to 140.10 F/g at the current density of 1 A/g, which was approximately three folds more than that of pristine nanofibers.It also retained the capacitance up to 96.2% after 1000 vigorous charge/discharge cycles. This functionalization technique opens up a new pathway in tuning the solubility nature of graphene oxide towards the synthesis of a graphene oxide-reinforced polymeric structure.

Effects of flaky rare earth oxide additives on the high temperature performance of nickel electrodes

Effects of flaky rare earth oxide additives including Er2O3,Tm2O3,and Yb2O3,Lu2O3 on high temperature and high rate discharge performance of nickel electrodes were investigated.The discharge efficiency at 0.2C reached 96% at 60 oC for electrodes with 1 at.% flaky rare earth oxides.The high rate discharge performance for electrodes with flaky rare earth oxides were improved significantly,for example,discharge efficiency at 5C improved from 50% to 70%.The results showed that the end charging potential of the ...

Electrooxidation of Nitric Oxide at a Glass Carbon Electrode Modified with Functionalized Single-walled Carbon Nanotube

The electrocatalytic oxidation of nitric oxide（NO） at a glass carbon electrode（GC） modified with functionalized single-walled carbon nanotubes（SWCNTs） was investigated by cyclic voltammetry（CV） and electrochemical impedance spectroscopy（EIS）.It was found that the SWCNT modified electrode could speed greatly up the electron transfer rate compared with the bare GC electrode.After the SWCNT was treated with alkali or mixed acids,the reaction rate and activation energy of NO electrooxidation were changed to different extent.Chemical modification of the SWCNT surface is one of the most powerful methods to change the sensitivity of NO electrooxidation reaction.The modified electrode with SWCNT obtained by the firstly alkali treatment and then the mixed acids treatment was the best one for NO electrooxidation,the result of CV was also confirmed by that of EIS.The anodic processes of NO were recognized more clearly by exploring the reaction mechanism of NO electrooxidation at the SWCNT modified electrode.

A sensitive electrochemical detection of metronidazole in synthetic serum and urine samples using low-cost screen-printed electrodes modified with reduced graphene oxide and C60

Monitoring the concentration of antibiotics in body fluids is essential to optimizing the therapy and minimizing the risk of bacteria resistance,which can be made with electrochemical sensors tailored with appropriate materials.In this paper,we report on sensors made with screen-printed electrodes(SPE)coated with fullerene(C60),reduced graphene oxide(rGO)and Nafion(NF)(C60-rGO-NF/SPE)to determine the antibiotic metronidazole(MTZ).Under optimized conditions,the C60-rGO-NF/SPE sensor exhibited a linear response in square wave voltammetry for MTZ concentrations from 2.5×10^(-7) to 34×10^(-6) mol/L,with a detection limit of 2.1×10^(-7) mol/L.This sensor was also capable of detecting MTZ in serum and urine,with recovery between 94%and 100%,which are similar to those of the standard chromatographic method(HPLC-UV).Because the C60-rGO-NF/SPE sensor is amenable to mass production and allows for MTZ determination with simple principles of detection,it fulfills the requirements of therapeutic drug monitoring programs.

Unique ZnS nanobuns decorated with reduced graphene oxide as an efficient and low-cost counter electrode for dye-sensitized solar cells

Unique ZnS nanobuns decorated with reduced graphene oxide （ROO） was synthesized and found to exhibit a synergetic effect as a highly efficient and low-cost counter electrode （CE） in dye-sensitized solar cells （DSCs）. Using this ZnS-ROO CE, a power conversion efficiency （PCE） of 7.03% was achieved. This value was 53% and 41 % higher than those of pure ZnS and ROO CEs, respectively. The ZnS-ROO nanocomposite is indeed an efficient and cost-effective Pt-like alternative for iodine reduction reaction.

New layered metal oxides as positive electrode materials for room-temperature sodium-ion batteries

In order to achieve better Na storage performance, most layered oxide positive electrode materials contain toxic and expensive transition metals Ni and/or Co, which are also widely used for lithium-ion batteries. Here we report a new quaternary layered oxide consisting of Cu, Fe, Mn, and Ti transition metals with O3-type oxygen stacking as a positive electrode for room-temperature sodium-ion batteries. The material can be simply prepared by a high-temperature solidstate reaction route and delivers a reversible capacity of 94 m Ah/g with an average storage voltage of 3.2 V. This paves the way for cheaper and non-toxic batteries with high Na storage performance.

High-Entropy Perovskite Oxide: A New Opportunity for Developing Highly Active and Durable Air Electrode for Reversible Protonic Ceramic Electrochemical Cells

Reversible proton ceramic electrochemical cell(R-PCEC)is regarded as the most promising energy conversion device,which can realize efficient mutual conversion of electrical and chemical energy and to solve the problem of large-scale energy storage.However,the development of robust electrodes with high catalytic activity is the main bottleneck for the commercialization of R-PCECs.Here,a novel type of high-entropy perovskite oxide consisting of six equimolar metals in the A-site,Pr_(1/6)La_(1/6)Nd_(1/6)Ba_(1/6)Sr_(1/6)Ca_(1/6)CoO_(3−δ)(PLN-BSCC),is reported as a high-performance bifunctional air electrode for R-PCEC.By harnessing the unique functionalities of multiple ele-ments,high-entropy perovskite oxide can be anticipated to accelerate reaction rates in both fuel cell and electrolysis modes.Especially,an R-PCEC utilizing the PLNBSCC air electrode achieves exceptional electrochemical performances,demonstrating a peak power density of 1.21 W cm^(−2)for the fuel cell,while simultaneously obtaining an astonishing current density of−1.95 A cm^(−2)at an electrolysis voltage of 1.3 V and a temperature of 600℃.The significantly enhanced electrochemical performance and durability of the PLNBSCC air electrode is attributed mainly to the high electrons/ions conductivity,fast hydration reactivity and high configurational entropy.This research explores to a new avenue to develop optimally active and stable air electrodes for R-PCECs.

Development and optimisation of electrode materials in solid oxide fuel cells

Solid oxide fuel cell (SOFC) is an all solid electrochemical device to convert fuels such as hydrogen and natural gas to electricity with high efficiency and very low greenhouse gas emission compared to traditional thermal power generation plants. Moreover, the reliability and efficiency of SOFC is critically dependent on the performance and stability of its components including anode, cathode and electrolyte. This in turn is largely dependent on the material selection and the fabrication processes. In this paper, specific examples are given to demonstrate strategy and process in the development and optimisation of electrode materials such as Ni/Y 2O 3 ZrO 2 cermet anodes and (LaSr)MnO 3 based cathodes. The results also demonstrate the importance of fabrication processes and that the understanding of the electrode process plays a very important role in the optimisation process of electrode materials.

Radio-frequency magnetron sputtered thin-film La_(0.5)Sr_(0.5)Co_(0.95)Nb_(0.05)O_(3-δ) perovskite electrodes for intermediate temperature symmetric solid oxide fuel cell(IT-SSOFC)

The present work explores the application of La_(0.5)Sr_(0.5)Co_(0.95)Nb_(0.05)O_(3-δ)(LSCNO)perovskite as electrode material for the symmetric solid oxide fuel cell.Symmetric solid oxide fuel cells of thin-film LSCNO electrodes were prepared to study the oxygen reduction reaction at intermediate temperature.The Rietveld refinement of syn-thesized material shows a hexagonal structure with the R-3c space group of the prepared perovskite material.Lattice parameter and fractional coordinates were utilized to calculate the oxygen ion diffusion coefficient for molecular dynamic simulation.At 973 K,the oxygen ion diffusion of LSCNO was 1.407×10^(-8)cm^(2)s^(-1) higher by order of one magnitude than that of the La_(0.5)Sr_(0.5)Co_(0.95)Nb_(0.05)O_(3-δ)(7.751×10^(-9)cm^(2)^(-1)).The results suggest that the Nb doping provide the structural stability which improves oxygen anion diffusion.The enhanced structural stability was analysed by the thermal expansion coefficient calculated experimentally and from molecular dynamics simulations.Furthermore,the density functional theory calculation revealed the role of Nb dopant for oxygen vacancy formation energy at Sr-0 and La-O planes is lower than the undoped structure.To understand the rate-limiting process for sluggish oxygen diffusion kinetics,80 nm and 40 nm thin films were fabricated using radio frequency magnetron sputtering on gadolinium doped ceria electrolyte substrate.The impedance was observed to increase with an increasing thickness,suggesting the bulk diffusion as a rate-limiting step for oxygen ion diffu-sion.The electrochemical performance was analysed for the thin-flm symmetric solid oxide fuel cell,which achieved a peak power density of 390 mW cm^(-2) at 1.02 V in the presence of H_(2) fuel on the anode side and air on the cathode side.

Electro-catalytic effect of manganese oxide on oxygen reduction at teflonbonded carbon electrode

Oxygen reduction(OR)on Teflon-bonded carbon electrodes with manganese oxide as catalyst in 6 mol/L KOH solution was investigated using AC impedance spectroscopy combined with other techniques. For OR at this electrode, the Tafel slope is –0.084 V/dec and the apparent exchange current density is (1.02-3.0)×10-7 A/cm2. In the presence of manganese oxide on carbon electrode, the couple Mn3+/Mn4+ reacts with the O2 adsorbed on carbon sites forming O ?2 radicals and acceletes the dismutation of O 2?, which contributes to the catalytic effect of manganese oxide for OR reaction.

Electro-catalytic oxidation of phenol with Ti-base lead dioxide electrode

The Ti base PbO 2 electrode prepared by electrodeposition of PbO 2 on the surface of titanium was used for electro catalytic oxidation of phenol in waste water. The experimental results show that the electrodeposition of PbO 2 at a higher current density for a short time, then followed by a lower current density can get a compact and combinative PbO 2 layer. The properties of a Ti/PbO 2 electrode with an interlayer of oxide are the best. When this kind of electrode is used to treat phenol containing waste water, the phenol removal rate is higher and the slot voltage is lower. In addition, by using the phenol removal rate as an index, the influences of electrolysis current density, mass transfer condition and pH were studied and the optimal condition was confirmed.

Improving the activity and stability of Ni-based electrodes for solid oxide cells through surface engineering:Recent progress and future perspectives

Solid oxide cells(SOCs)have attracted great attention in the past decades because of their high conversion efficiency,low environmental pollution and diversified fuel options.Nickel-based catalysts are the most widely used fuel electrode materials for SOCs due to the low price and high activity.However,when hydrocarbon fuels are employed,nickel-based electrodes face serious carbon deposition challenges,leading to a rapid decline of cell performance.Great efforts have been devoted to understanding the occurrence of the coking reaction,and to improving the stability of the electrodes in hydrocarbon fuels.In this review,we summarize recent research progress of utilizing surface modification to improve the stability and activity of Ni-based electrodes for SOCs by preventing carbon coking.The review starts with a briefly introduction about the reaction mechanism of carbon deposition,followed by listing several surface modification technologies and their working principles.Then we introduce representative works using surface modification strategies to prevent carbon coking on Ni-based electrodes.Finally,we highlight future direction of improving electrode catalytic activity and anti-coking performance through surface engineering.

Study on the Multi-Sensing System Based on the Tin Oxide pH Electrode

In this study,the multi-sensing system based on the tin oxide pH electrode for the ion-determination was presented. With the advantages of the real-time supervisory control apparatus,the measured values could be displayed on the liquid crystal display (LCD) immediately.In this study,the basic sensor was the tin oxide pH electrode,which was fabricated by radio frequency (r.f.) sputtering system on the indium tin oxide (ITO)/glass substrate.Moreover,the major blocks of the system consist of the tin oxide electrode-based ion selective electrodes (ISEs),an analog front-ended readout circuit,a microcontroller with built-in analog to digital (A/D) converter.In addition,by the embedded system design,the measurement results can be transmitted to a portable system or computer through the Universal Serial Bus (USB) and Universal Asynchronous Receiver Transmitter (UART) interface immediately.According to the experimental results,the multi-sensing system has high performance and reliability for pH,K^+,and Na^+ detection.

An Antimony Oxide pH Electrode for Tissue Culture Medium

A new approach named“caterpillar melt method”was developed to prepare wire type antimony oxide electrode for pH measurement in agar medium for tissue culture.A micro antimony wire was prepared from melt of the metal with the help of a glass capillary and the surface of the wire was oxidized in nitrate melt to obtain an antimony oxide electrode. Characterization results showed that the oxide layer is dense and uniform,with high physical and chemical stability.The electrode has a fast and stable response toward pH change for aqueous solutions.The potential of the antimony electrode has a linear relationship with the pH of the solution (R^2=1.00) with a sensitivity of 54.1mV/pH.The electrode works well and is more stable in agar medium during tissue culture for pH monitoring.

Study on the Tin Oxide Sol-Gel Membrane as a pH Sensing Electrode

In this study,tin oxide sensing membrane was derived by sol-gel method and was coated onto indium tin oxide (ITO) glass substrate by spin-coating technique to fabricate a pH sensing electrode.Besides,the morphology of the tin oxide membrane has been discussed through the instrumental analysis.Furthermore,the sensing characteristics of the pH electrode was measured by commercial instrumental amplifier as the readout circuit.Owing to the sol-gel method has many advantages such as easy fabrication of gel solution,ability to dope other materials without any expensive fabricating equipment.Hence,it is suitable for the mass production of a disposable sensor.

Transparent conducting indium-tin-oxide(ITO) film as full front electrode in Ⅲ–Ⅴ compound solar cell

The application of transparent conducting indium-tin-oxide （ITO） film as full front electrode replacing the conven- tional bus-bar metal electrode in III-V compound GalnP solar cell was proposed. A high-quality, non-rectifying contact between ITO and 10 nm N＋-GaAs contact layer was formed, which is benefiting from a high carrier concentration of the terrilium-doped N＋-GaAs layer, up to 2×10^19 cm^-3. A good device performance of the GalnP solar cell with the ITO electrode was observed. This result indicates a great potential of transparent conducting films in the future fabrication of larger area flexible III-V solar cell.