Electrosynthesis, optical modeling and electrocatalytic activity of Ni-MWCNT-PT nanocomposite film

Prussian-blue-analogue derived FeNi2S4/NiS nanoframes supported by N-doped graphene for highly efficient methanol oxidation electrocatalysis

The design of effective and robust non-noble metal electrocatalysts to enhance catalytic reaction kinetic is critical to promote methanol oxidation catalysis. Herein, hierarchical Prussian blue analogue (PBA)-derived sulfide heterostructures supported by N-doped graphene (FeNi₂S₄/NiS-NG) as efficient catalysts have been developed for methanol oxidation reaction (MOR). Benefiting from the merits of hollow nanoframes structure and heterogeneous sulfide synergy, FeNi₂S₄/NiS-NG composite not only possesses abundant active sites to boost the catalytic properties but also alleviates the CO poisoning effect during the process exhibiting favorable kinetic behavior toward MOR. Specifically, the remarkable catalytic activity (97.6 mA cm^-2/1544.3 mA mg^-1) of FeNi₂S₄/NiS-NG for methanol oxidation was achieved, superior to most reported non-noble electrocatalysts. Additionally, the catalyst showed competitive electrocatalytic stability, with a current density of over 90% after 2000 consecutive CV cycles. This study offers promising insights into the rational modulation of the morphology and components of precious-metal-free catalysts for fuel cell applications.

Designing New Material Based on Functionalized Multi-Walled Carbon Nanotubes and Cu(OH)2–Cu2O/Polypyrrole Catalyst for Ethanol Oxidation in Alkaline Medium

In this work, copper(II) hydroxide (Cu(OH)2) and copper oxide (Cu2O) nanostructures are deposited on functionalized multi-walled carbon nanotubes/polypyrrole to report an efficient electrocatalyst for ethanol oxidation in alkaline medium. In the first step, the deposition of functionalized multi-walled nanotubes of carbon (F-MWCNTs) on the electrode surface was carried out using drop casting mode followed by the electrodeposition of polypyrrole (PPy) and copper nanoparticles (Cu-Nps) using galvanostatic mode. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed in order to study the morphology and the structure of the elaborated catalysts. Electrochemical characterization conducted by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) revealed that the introduction of functionalized multi-walled carbon nanotubes enhances the electric properties of the nanocomposites and offers a large active surface area. The prepared electrocatalyst was then tested in a solution of 0.1 M NaOH containing 0.2 M of ethanol showing high performance (7 mA cm−2 at 0.85 V vs Ag/AgCl) and good stability (over 1800 s) toward ethanol oxidation.

Electrocatalytic Oxidation of Ethanol on the Surface of Graphene Based Nanocomposites: An Introduction and Review to it in Recent Studies

This review gives an overview of the electrochemical investigations about the properties of various types of graphene composites in the ethanol oxidation. Various routes to provide appropriate graphene-based materials required electrochemical techniques for investigation of different types of the materials as well as their performance and efficacy in ethanol oxidation are discussed in detail. Furthermore, it is demonstrated that the incorporation of suitable materials, e. g. noble metals (graphene-supported binary and ternary metal nanoparticles), metal oxides, conductive polymer, etc, with graphene results in excellent electrocatalytic activity, superb durability and selectivity in ethanol oxidation. Immobilization of electrocatalytically active NPs on graphene supports using physical approaches is considered as an effective route to prepare direct ethanol fuel cell (DEFC) anode catalysts.

Enhancement of corrosion resistance of polypyrrole using metal oxide nanoparticles: Potentiodynamic and electrochemical impedance spectroscopy study

We introduce a simple and facile strategy for dispersing of nanoparticles within a p-type conducting polymer matrix by in situ electropolymerization using oxalic acid as the supporting electrolyte. Coatings prepared from polypyrrole-nano-metal oxide particles synthesized by in situ polymerization were found to exhibit excellent corrosion resistance much superior to polypyrrole (Ppy) in aggressive environments. The anti-corrosion behavior of polypyrrole films in different states and the presence of TiO₂, Mn₂O₃ and ZnO nanoparticles synthesized by electropolymerization on Al electrodes have been investigated in corrosive solutions using potentiodynamic polarization and electrochemical impedance spectroscopy. The electrochemical response of the coated electrodes in polymer and nanocomposite state was compared with bare electrodes. The use of TiO₂ nanoparticles has proved to be a great improvement in the performances of polypyrrole films for corrosion protection of Al samples. The polypyrrole synthesized in the presence of TiO₂ nanoparticles coated electrodes offered a noticeable enhancement of protection against corrosion processes. The exceptional improvement of performance of these coatings has been associated with the increase in barrier to diffusion, prevention of charge transport by the nanosize TiO₂, redox properties of polypyrrole as well as very large surface area available for the liberation of dopant due to nano-size additive.

Facile electrosynthesis of nano flower like metal-organic framework and its nanocomposite with conjugated polymer as a novel and hybrid electrode material for highly capacitive pseudocapacitors

The [Cu(btec)_0.5DMF] (H₄btec=1,2,4,5-benzenetetracarboxylate acid) was electrosynthesized on the graphite working electrode by applying catholic potential. The [Cu(btec)_0.5DMF] grows on a graphite surface which results from the coordination of 1,2,4,5-benzenetetracarboxylate anions with Cu²⁺ cations. The electrosynthesized [Cu(btec)_0.5DMF] was characterized by X-ray diffraction, scanning electron microscopy. Furthermore, POAP/Cu(btec)_0.5DMF nanocomposite film electrosynthesized on the surface of the carbon paste electrode by cyclic voltammetry. Different electrochemical methods including galvanostatic charge-discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy are carried out in order to investigate the performance of the system. This work introduces new nanocomposite materials for electrochemical redox capacitors with advantages including ease synthesis, high active surface area and stability in an aqueous electrolyte.

Facile electrosynthesis, characterisation and electrochemical performance of poly ortho aminophenol/Al5Y3O12 nanocomposite as a new high efficient supercapacitor

In this paper, firstly Al₅Y₃O₁₂ has been synthesized without any impurities using pulse electrochemical deposition and then fabricated POAP/YAG films to serve as the active electrode for the electrochemical supercapacitor.

Physicoelectrochemical properties of facilely electrosynthesized reduced graphene oxide/p-type conductive polymer nanocomposite film

As electro-active electrodes, composites of reduced graphene oxide and poly ortho aminophenol (POAP) with good uniformity are prepared by electropolymerization. In comparison with Ni-POAP, the Ni-rGO/POAP-modified electrode shows a higher response for methanol oxidation.

One-Step Fabrication of a Multifunctional Magnetic Nickel Ferrite/Multi-walled Carbon Nanotubes Nanohybrid-Modified Electrode for the Determination of Benomyl in Food

Benomyl, as one kind of agricultural pesticide, has adverse impact on human health and the environment. It is urgent to develop effective and rapid methods for quantitative determination of benomyl. A simple and sensitive electroanalytical method for determination of benomyl using a magnetic nickel ferrite (NiFe2O4)/multi-walled carbon nanotubes (MWCNTs) nanohybrid-modified glassy carbon electrode (GCE) was presented. The electrocatalytic properties and electroanalysis of benomyl on the modified electrode were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In the phosphate-buffered saline (PBS) of pH 6.0, this constructed biosensor exhibited two linear relationships with the benomyl concentration range from 1.00 × 10(-7) to 5.00 × 10(-7) mol/L and from 5.00 × 10(-7) to 1.00 × 10(-5) mol/L, respectively. The detection limit was 2.51 × 10(-8) mol/L (S/N = 3). Moreover, the proposed method was successfully applied to determine benomyl in real samples with satisfactory results. The NiFe2O4/MWCNTs/GCE showed good reproducibility and stability, excellent catalytic activity, and anti-interference.

Synthesis and highly efficient supercapacitor behavior of a novel poly pyrrole/ceramic oxide nanocomposite film

This work introduces new nanocomposite materials (Ppy/YAG) for electrochemical redox capacitors with advantages including long life cycle and stability in an aqueous electrolyte to that of commonly used ruthenium based pervoskites.

Physioelectrochemical and DFT investigation of metal oxide/p-type conductive polymer nanoparticles as an efficient catalyst for the electrocatalytic oxidation of methanol

Poly tyramine–NiO as an efficient electrocatalyst was prepared by in situ electropolymerization of tyramine in the presence of the SDS under ultrasonic irradiation.

Physioelectrochemical investigation of the supercapacitive performance of a ternary nanocomposite by common electrochemical methods and fast Fourier transform voltammetry

Fast Fourier transform continuous cyclic voltammetry as a new technique for the explanation of a composite electrode for supercapacitors.

Continuous fast Fourier transform admittance voltammetry as a new approach for studying the change in morphology of polyaniline for supercapacitors application

In this study, continuous fast Fourier transform admittance voltammetry (CFFTAV) was used to study and characterize the surface morphology of polyaniline (PANI) on glassy carbon (GC) electrodes.