Effect Of Electric Field Research Articles

Effects of audio frequency electric fields on the esterification reactions of acetic acid with C4-C8 branched alcohols

Effects of audio frequency electric fields on the esterification reactions of acetic acid with C4-C8 branched alcohols

Effect of external electric and magnetic fields on the structural properties of gold nanoclusters formed during inert-gas condensation process in different environments using molecular dynamics simulations

In this article, we have investigated growth path, stabilities, and structures of formed Au nanoclusters during the gas phase process with different environments (water and Ar) in the presence of external electric and magnetic fields using molecular dynamics (MD) simulation. Our results showed that the number of the formed cluster increases by applying the strong magnetization. By increasing the concentration of water in 50% H2O–50% Ar and in 100% H2O environments and applying a magnetic field, the hollow porous (HP) nanoparticles are created, which can be considered as a new method for the formation of HP nanoparticles. Applying the stronger magnetic field increase the rate of formation of HP nanoparticles at larger simulation times. The number of HP nanoparticles also increases in the presence of strong and weak electric fields by increasing the concentration of water in the environment.

Effect of Electric Fields on the Decomposition of Phosphate Esters.

Phosphate esters decompose on metal surfaces and form protective polyphosphate films. For many applications, such as in lubricants for electric vehicles and wind turbines, an understanding of the effect of electric fields on molecular decomposition is urgently required. Experimental investigations have yielded contradictory results, with some suggesting that electric fields improve tribological performance, while others have reported the opposite effect. Here, we use nonequilibrium molecular dynamics (NEMD) simulations to study the decomposition of tri-n-butyl phosphate (TNBP) molecules nanoconfined between ferrous surfaces (iron and iron oxide) under electrostatic fields. The reactive force field (ReaxFF) method is used to model the effects of chemical bonding and molecular dissociation. We show that the charge transfer with the polarization current equalization (QTPIE) method gives more realistic behavior compared to the standard charge equilibration (QEq) method under applied electrostatic fields. The rate of TNBP decomposition via carbon-oxygen bond dissociation is faster in the nanoconfined systems than that in the bulk due to the catalytic action of the surfaces. In all cases, the application of an electric field accelerates TNBP decomposition. When electric fields are applied to the confined systems, the phosphate anions are pulled toward the surface with high electric potential, while the alkyl cations are pulled to the surface with lower potential, leading to asymmetric film growth. Analysis of the temperature- and electric field strength-dependent dissociation rate constants using the Arrhenius equation suggests that, on reactive iron surfaces, the increased reactivity under an applied electric field is driven mostly by an increase in the pre-exponential factor, which is linked to the number of molecule-surface collisions. Conversely, the accelerated decomposition of TNBP on iron oxide surfaces can be attributed to a reduction in the activation energy with increasing electric field strength. Single-molecule nudged-elastic band (NEB) calculations also show a linear reduction in the energy barrier for carbon-oxygen bond breaking with electric field strength, due to stabilization of the charged transition state. The simulation results are consistent with experimental observations of enhanced and asymmetric tribofilm growth under electrostatic fields.

Multiphoton ionization in a photonic crystal based on carbon nanotubes under the action of a few cycle optical pulse

We considered a theoretical model of the interaction of a one-dimensional few cycles optical pulse with a nonlinear medium of semiconductor carbon nanotubes, which has a spatial modulation of the refractive index in the direction of pulse propagation (a one-dimensional photonic crystal). The results of the dependence of the rate of one- and two-photon ionization on the intensity of the short-wavelength pulse are shown. The effect of additional external electric and magnetic fields on the photoionization rate is considered.

Interface engineering of AgI/(P, K)-g-C3N4 novel S-scheme heterostructures as a highly efficient photocatalyst for RhB degradation

In this study, we developed an in-situ deposition method to load small-sized AgI nanoparticles as an oxidative photocatalyst (OP) onto phosphorus (P) and potassium (K) co-doped two-dimensional porous g-C3N4 (PK-CN-N) as a reductive photocatalyst (RP), forming an S-scheme heterojunction photocatalyst AgI/PK-CN-N. PK-CN-N achieved morphology control and element doping, leading to surface functionalization and heterostructure formation for the AgI/PK-CN-N photocatalyst. Notably, the 50AgI/PK-CN-N composite demonstrated an approximately 95 % removal efficiency for RhB within 30 minutes, 17.6 times higher than pure g-C3N4, surpassing most reported g-C3N4-based photocatalysts. The enhanced photocatalytic efficiency is attributed to the surface modification strategy and heterostructure formation of g-C3N4, which broadens the visible light response range, increases the number of active sites, improves the separation of photogenerated electron-hole pairs, and enhances REDOX capabilities. The band structure of the composite was elucidated through Mott-Schottky analysis and UV–vis DRS. The formation of the AgI/PK-CN-N S-scheme heterojunction and its charge transfer mechanism was confirmed through XPS, band structure analysis, KPFM, and EPR spectroscopy. Experimental data confirmed the presence of a strong and effective interface electric field between the two semiconductors, leading to band bending and accelerated charge separation. Additionally, the introduction of small-sized AgI semiconductors enhanced the exposure of the coupling interface, further improving catalytic performance. The reusability and lifespan of the catalyst were also analyzed, showing that after four cycles, the photocatalytic activity remained above 92 %.

Evaluating the Ability of External Electric Fields to Accelerate Reactions in Solution.

This study investigates the catalytic effects of external electric fields (EEFs) on two reactions in solution: the Menshutkin reaction and the Chapman rearrangement. Utilizing a scanning tunneling microscope-based break-junction (STM-BJ) setup and monitoring reaction rates through high-performance liquid chromatography connected to a UV detector (HPLC-UV) and ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-q-ToF-MS), we observed no rate enhancement for either reaction under ambient conditions. Density functional theory (DFT) calculations indicate that electric field-induced changes in reactant orientation and the minimization of activation energy are crucial factors in determining the efficacy of EEF-driven catalysis. Our findings suggest that the current experimental setups and field strengths are insufficient to catalyze these reactions, underscoring the importance of these criteria in assessing the reaction candidates.

Edge sites regulation, strain and electric field effect on MoS2/CoS2 heterojunction catalysts for hydrogen evolution reaction.

Heterojunction catalysts in the field of hydrogen evolution reaction (HER) from electrocatalytic water splitting have recently become a hot research topic. In this paper, we systematically calculated the HER catalytic performance of a MoS2/CoS2 heterojunction for the first time, considering the effect of edge sites regulation, strain and electric field. The results indicate that the MoS2/CoS2 heterojunction exhibits synergistic catalytic performance compared to MoS2 and CoS2, the HER catalytic activity of which can be improved by exposing more edge sites or regulating the S content on the edges, with an optimized ratio of 25%. Surprisingly, applying strain has a slight effect on the catalytic activity of the edge, however, an obvious effect on the basal plane. For example, applying 2% tensile strain on the MoS2/CoS2 heterojunction can improve the edge catalytic performance by 13%, and for the basal plane, this value can reach 92%. In this case, the catalytic performance of the basal plane is better than that of the edge with 2% and without strain. Since the basal plane accounts for the majority of the two-dimensional catalysts, the catalytic performance of the basal plane is generally much lower than that of the edge. This discovery is of great significance, which means by adjusting strain, the catalytic performance of the heterojunction catalyst is likely to be improved by orders of magnitude. Moreover, considering the actual experimental process, we also calculated the effect of the electric field and found that 0.7 V/Å electric field can enhance the HER catalytic activity of the MoS2/CoS2 heterojunction by 23%.

Effects of non-resonant intense laser, electric and magnetic fields on exciton binding energy and absorption spectra in the Gaussian double quantum well

Effects of non-resonant intense laser, electric and magnetic fields on exciton binding energy and absorption spectra in the Gaussian double quantum well

Enhanced interfacial electric field via sulfur vacancies modified ZnIn2S4-Vs@NiIn2S4 S-scheme photocatalysts for simultaneous H2 evolution and benzyl alcohol oxidation

Designing and developing efficient photocatalysts for H2 evolution and simultaneous oxidation of benzyl alcohol (BA) in aqueous environments provides a cutting-edge strategy for green synthesis. Nevertheless, the photocatalysts suffer from the low photoconversion efficiency because of the sluggish dynamics and repaid recombination of photogenerated charge carriers, which hindering their widespread applications. To address the limitation, a multifunctionnal sulfur vacancies (SVs) modified ZIS-Vs@NIS S-scheme heterojunction with a strong interfacial electric field effect was synthesized to use photocatalytic H2 production and BA oxidation, simultaneously. Experimental analysis supports that the synergistic effect of SVs and S-scheme heterojunction engineering result in a suitable energy band structure alignment and larger Fermi level potential difference. Those factors can realize effective charge transfer and separation, and enhance the photocatalytic performance. As anticipated, ZIS-Vs@NIS exhibited a superior photocatalytic performance with H2 and benzaldehyde (BAD) yields up to 168.1 and 146.1 μmol under the simulated solar-light irradiation for 1.0 h, respectively, which are approximately 13.3 and 11.8 times higher than pristine ZIS. Moreover, the photocatalytic H2 evolution coupled with BA oxidative dehydrogenation mechanism via S-scheme heterojunction over ZIS-Vs@NIS is also demonstrated in detail.

Heterogeneous Interface Design with Oxygen Vacancy-Rich Assistance High-Capacity Titanium-Based Oxide Anode Materials for Sodium-Ion Batteries.

Researchers are paying more attention to sodium-ion batteries (SIBs) because of their abundant supply of sodium resources and affordable price. TiO2 offers excellent safety and a long lifespan as an anode material for SIBs. However, the process kinetics is slow due to its limited Na+ storage efficiency, weak conductivity, and irreversible Na+ capture. In order to address these issues, this review uses a mix of the template approach and the double-hydrolysis method to manage the structure and diffusion of TiO2-based anode materials by synthesizing FeTiO3/TiO2 heterostructured double-shell microspheres (FTO). Through the built-in electric field effect caused by their heterostructures, FTO materials improve reaction kinetics, boost electronic conductivity, and lower the diffusion energy barrier of Na+. Their distinctive double-shell structure can increase electrolyte infiltration, shorten the diffusion distance between ions and electrons, and accommodate volume expansion during cycling. Furthermore, the irreversible capture of Na+ and the unfavorable interactions between the surface active site and electrolyte can be successfully inhibited by FTO heterostructures. FTO has an exceptionally high capacity (reaching 362.7 mA h g-1 after 60 cycles at 20 mA g-1) and excellent cycle stability (with a decay rate of 0.0061% after 1000 cycles at 2 A g-1). The strategy of constructing heterogeneous interfaces assists with high-performance SIB anode design.

Effect of Electron-Donating Substituents and an Electric Field on the ΔEST of Selected Imidazopyridine Derivatives: A DFT Study.

A series of thermally activated delayed fluorescent (TADF) molecules having an imidazopyridine acceptor, a benzene linker, and a 9,9-dimethyl-9,10-dihydroacridine donor are designed and examined using a quantum chemical approach. The above framework spatially separates the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO), minimizing their overlap, ultimately resulting in a reduced energy gap between the excited singlet and triplet states (ΔEST). The impact of electron-donating substituents (-Me, -Et, -t-Bu, -OMe, and -NMe2) on the donor moiety of the parent molecule 2-(4-(9,9-dimethylacridin-10(9H)-yl)phenyl)imidazo[1,2-a]pyridine-3,6-dicarbonitrile (Ac-CNImPy) is investigated. The calculated results revealed that for a given substituent, the para-substituted derivatives exhibit relatively less ΔEST, compared to that of the respective ortho- and meta derivatives. The value of ΔEST decreased with an increase in the electron-donating capacity of the substituent. Additionally, the ΔEST of the disubstituted derivatives is found to be less than that for the monosubstituted derivatives. The charge transport studies revealed that molecules with strong electron-donating substituents act as electron transporters. The effect of an external electric field (EEF) on ΔEST of the parent molecule Ac-CNIMPY and its derivative is also examined and revealed that the ΔEST can be further reduced by applying an electric field of appropriate strength in a direction perpendicular to the dipole moment of the molecule and in the plane of the acceptor moiety.

Coherence resonance in a memristive map neuron and adaptive energy regulation

Involvement of memristive term and additive physical variables including magnetic flux and charge can enhance the physical description of the biophysical neurons. Neural circuits coupled with memristors can be built and tamed to mimic the intrinsic biophysical characteristics and dynamical properties of biological neurons, and these memristive oscillator models are effective in predicting the mode transition in neural activities and self-organization in collective electric behaviors of neural networks. Any proposal of memristive map neurons requires reliable physical description. For example, the energy definition and self-adaptive working mechanism are crucial to verify the reliability of memristive maps. A capacitive variable is useful to describe the membrane potential, while the complexity of ion channels requires careful evaluation and description by using inductive variables relative to the electromagnetic field. In this work, a charge-controlled memristor is connected to an inductor in series for building a hybrid ion channel, and then a capacitor and a nonlinear resistor are combined to couple the ion channel. As a result, a simple memristive neural circuit is designed to discern the inner effect of electric field and magnetic field synchronously. The energy function is defined and verified with theoretical proof. Furthermore, a linear transformation is applied to convert this memristive neuron into a memristive map with an exact energy description, in which its dynamics and mode transition will be controlled by an adaptive law when its energy is beyond the threshold. Additive noise is imposed to induce coherence resonance, which can be detected by using the statistical analysis and average value for Hamilton energy function during changes in noise intensity. This scheme provides guidance for energy definition in memristive maps and the intrinsic energy regulation mechanism in neural activities is explained from physical and dynamical aspects.

Heterostructure VO2@VS2 tailored by one-step hydrothermal synthesis for stable and highly efficient Zn-ion storage

Abstract The increasing demand for advanced energy storage solutions has driven extensive research into Zn-ion batteries due to their safety, cost-effectiveness, and environmental compatibility. This study presents a synthesis and evaluation of VO2@VS2 hollow nanospheres as a novel cathode material for Zn-ion batteries. The VO2@VS2 composite, synthesized via a one-step hydrothermal method, demonstrates a significant improvement in electrochemical performance. The material exhibits a reversible capacity of 468 mAh g−1 at 0.1 A g−1 and maintains a high capacity of 237 mAh g−1 at 1.0 A g−1 over 1000 cycles with a retention rate of 85%. Electrochemical analyses reveal enhanced charge transfer and Zn-ion storage, attributed to the synergistic effect and built-in electric field of the VO2 and VS2 heterostructure. Additionally, the composite shows superior electrochemical kinetics, facilitating rapid ion transport and charge transfer. In-situ Raman analysis confirms the reversible Zn-ion storage mechanism, further validating the composite’s structural stability during cycling. Density functional theory calculations further support these findings, indicating the composite’s potential for high-rate capability and long-term cycling stability. This research highlights the promise of VO2@VS2 hollow nanospheres in advancing the performance of aqueous Zn-ion batteries.

Effects of Normal and Lateral Electric Fields on Membrane Mechanical Properties.

As a core component of biological and synthetic membranes, lipid bilayers are key to compartmentalizing chemical processes. Bilayer morphology and mechanical properties are heavily influenced by electric fields, such as those caused by biological ion concentration gradients. We present atomistic simulations exploring the effects of electric fields applied normally and laterally to lipid bilayers. We find that normal fields decrease membrane tension, while lateral fields increase it. Free energy perturbation calculations indicate the importance of dipole-dipole interactions to these tension changes, especially for lateral fields. We additionally show that membrane area compressibilities can be related to their cohesive energies, allowing us to estimate changes in membrane bending rigidity under applied fields. We find that normal and lateral fields decrease and increase bending rigidity, respectively. These results point to the use of directed electric fields to locally control membrane stiffness, thereby modulating associated cellular processes.

Effect of External Electric Field on Nitrogen Activation on a Trimetal Cluster.

Efficient nitrogen (N2) fixation and activation under mild conditions are crucial for modern society. External electric fields (Felectric) can significantly affect N2 activation. In this work, the effect of Felectric on N2 activation by Nb3 clusters supported in a sumanene bowl was studied by density functional theory calculations. Four typical systems at different stages of N-N activation were studied, including two intermediates and two transition states. The impact of Felectric on various properties related to N2 activation was investigated, including the N-N bond length, overlap population density of states (OPDOS), total energy of the system, adsorption energy of N2, decomposition of energy changes, and electron transfer. The sumanene not only functions as a support and protective substrate, but also serves as a donor or acceptor under different Felectric conditions. Negative Felectric is beneficial to N-N bond activation because it promotes electron transfer to the N-N region and improves the d-π* orbital hybridization between metals and N2 in the activation process. Positive Felectric improves d-π* orbital hybridization only when the N-N is nearly dissociated. The microscopic mechanism of Felectric's effects provides insight into N2 activation and theoretical guidance for the design of catalytic reaction conditions for nitrogen reduction reactions (NRR).

Solute Dispersion in Casson Blood Flow through a Stenosed Artery with the Effect of Temperature and Electric Field

This study develops a mathematical model to address solute dispersion in arterial blood flow, particularly considering the effects of temperature and electric fields using the Casson fluid model. Given the physiological importance of drug delivery within the human vascular system, understanding these dynamics is crucial, especially in the presence of cardiovascular diseases (CVD). The Generalized Dispersion Model (GDM) is employed to simulate the dispersion function. Results demonstrate that elevated temperatures and electric fields enhance drug uptake and distribution by increasing blood flow. The model accurately predicts drug behavior in narrowed arteries, optimizing dosage regimens and improving therapeutic outcomes. Visual representations and detailed discussions of these findings are presented in the subsequent sections. The results are validated against a previous study that did not consider the effects of stenosis height, temperature and electric field. The findings suggest a strong agreement between the two studies. Additionally, an increase in mean absorption leads to an increase in velocity. When mean absorption increases, the functions of steady dispersion and overall dispersion decrease, while the function of unsteady dispersion increases. The reverse behavior is observed for the electric field. The study concludes that integrating temperature and electric field effects into drug delivery systems can significantly enhance treatment efficacy and reduce side effects, providing a valuable tool for advanced targeted therapies in CVD and cancer management.

Growth of Ba2CoWO6 single crystals and their magnetic, thermodynamic and electronic properties

This study explores the bulk crystal growth, structural characterization, and physical property measurements of the cubic double perovskite Ba2CoWO6(BCWO). In BCWO, Co2+ions form a face-centred cubic lattice with non-distorted cobalt octahedra. The compound exhibits long-range antiferromagnetic order belowTN= 14 K. Magnetization data indicated a slight anisotropy along with a spin-flop transition at 10 kOe, a saturation field of 310 kOe and an ordered moment of 2.17µB atT= 1.6 K. Heat capacity measurements indicate an effectivej= 1/2 ground state configuration, resulting from the combined effects of the crystal electric field and spin-orbit interaction. Surface photovoltage analysis reveals two optical gaps in the UV-Visible region, suggesting potential applications in photocatalysis and photovoltaics. The magnetic and optical properties highlight the significant role of orbital contributions within BCWO, indicating various other potential applications.

Dynamics of memristive circuit driven by Josephson junction

The nonlinear circuit with charge-controlled memristor (CCM) can capture the external electric field effect. The nonlinear circuit with Josephson junction (JJ) can estimate the external magnetic field effect. Therefore, we propose an enhanced functional circuit by connecting a CCM and a JJ into a simple RLC nonlinear circuit. This enchanced circuit can estimate the external electromagnetic fields concurrently. The dynamical equations of the new memristive circuit and its Hamilton energy function are obtained by using the Kirchhoff’s law and the Helmholtz’s theorem. Furthermore, the complex dynamics of memristive circuit are investigated by applying bifurcation diagrams, Lyapunov exponents and time sampled series. The simulation experiment results indicate that the electromagnetic field has a great influence on complex dynamics of memristive circuit. In fact, this new nonlinear circuit is also a functional neural circuit, and it can be used to study the collective dynamic of functional neural network under the condition of an external electromagnetic fields.

Effect of external electric fields on the ionic conductivity of the PET ion-track membrane

Polymeric ion track-etched membranes with asymmetric pores have been the subject of increased interest in both the academia and industry in recent decades. This interest is related to the rectification behavior of the membranes and their possible applications. In this work, the polyethylene terephthalate (PET) membranes with conical ion tracks were investigated for different etching conditions. Thin PET membranes were prepared using irradiated foils etched in a NaOH bath with the help of external electric fields (AC/DC) of a specific polarity. After etching, the I-V characteristics of the membranes were examined in the KCl solutions with different molarities. The obtained results showed that the I-V relations are strongly non-linear, thus confirming the rectification behavior of the membranes. It turned out that the external AC and DC fields applied during etching play an important role. They make it possible to influence the pore etching process, and so the properties of the membranes, which is important for the intended applications. Keywords: polymeric membranes, asymmetric pores, polyethylene terephthalate, I-V characteristics, transport phenomena

Band Versus Hopping Transport in Conducting Polymers by Ab Initio Molecular Dynamics: Exploring the Effect of Electric Field, Trapping and Temperature

Band Versus Hopping Transport in Conducting Polymers by Ab Initio Molecular Dynamics: Exploring the Effect of Electric Field, Trapping and Temperature