Charge Flow Research Articles

Oxygen-bridged Schottky junction in ZnO–Ni3ZnC0.7 promotes photocatalytic reduction of CO2 to CO: Steering charge flow and modulating electron density of active sites

Developing carbon dioxide (CO2) photocatalysts from transition metal carbides (TMCs) with abundant active sites, modulable electron cloud density, as well as low cost and high stability is of great significance for artificial photosynthesis. Building an efficient electron transfer channel between the photo-excitation site and the reaction-active site to extract and steer photo-induced electron flow is necessary but challenging for the highly selective conversion of CO2. In this study, we achieved an oxygen-bridged Schottky junction between ZnO and Ni3ZnC0.7 (denoted as Znoxide–O–ZnTMC) through a ligand-vacancy strategy of MOF. The ZnO–Ni3ZnC0.7 heterostructure integrates the photo-exciter (ZnO), high-speed electron transport channel (Znoxide–O–ZnTMC), and reaction-active species (Ni3ZnC0.7), where Znoxide–O–ZnTMC facilitates the transfer of excited electrons in ZnO to Ni3ZnC0.7. The Zn atoms in Ni3ZnC0.7 serve as electron-rich active sites, regulating the CO2 adsorption energy, promoting the transformation of *COOH to CO, and inhibiting H2 production. The ZnO–Ni3ZnC0.7 shows a high CO yield of 2674.80 μmol g–1h–1 with a selectivity of 93.40 % and an apparent quantum yield of 18.30 % (λ = 420 nm) with triethanolamine as a sacrificial agent. The CO production rate remains at 96.40 % after 18 h. Notably, ZnO–Ni3ZnC0.7 exhibits a high CO yield of 873.60 μmol g–1h–1 with a selectivity of 90.20 % in seawater.

In situ synthesis of g-C3N4/Ag@Ag3PO4 S-scheme heterostructure with tandem ohmic- and d-p bond-junction for photocatalytic reduction of CO2

Low-mass interfacial contacts and poor charge transfer efficiency severely limit the CO2 photoreduction performance of semiconductor heterojunctions. In this work, g-C3N4/Ag@Ag3PO4 S-scheme heterojunction is prepared by an in-situ growth method. The main product for CO2 photoreduction is CO with the selectivity of 97 %. The evolution rate of CO for optimal g-C3N4/Ag@Ag3PO4 heterojunction is 123.8 μmol g−1 h−1, which are 8.3-and 3.4-fold higher than those of pristine Ag3PO4 and g-C3N4, respectively. It is found that Ag3PO4, Ag, and g-C3N4 form strong interacting interfacial structure, in which Ag3PO4 links with Ag nanoparticles through tandem Ohmic contact. More importantly, σ bonds are formed via hybridization of px orbital for C and N with dx2-y2 orbitals of Ag in g-C3N4/Ag@Ag3PO4 S-scheme heterojunction, establishing an atomic-level dx2-y2(Ag)-px(C,N) charge flow highway. This work provides new viewpoints into the design of heterojunction photocatalysts with high-quality interfaces and highlights the insights of charge transfer behavior in regulating the catalytic activity.

Síntese e caracterização de filmes de Polipirrol dopados com Tetraquis(4-carboxifenil) porfirina para aplicações fotoelectroquímicas

Photoelectrochemistry is emerging as a promising technology for harvesting and utilizing solar energy in a wide range of applications. However, electrode materials still need to be improved to achieve optimal performance. Conductive polymers emerge as particularly promising organic compounds for this purpose due to their highly versatile properties. In this study, the galvanostatic synthesis of polypyrrole films co-doped with tetrakis(4-carboxyphenyl) porphyrin (PPy/TCPP) on fluorine doped tin oxide (FTO)-coated glass substrates was performed for the first time. In addition, an evaluation of these films as photoelectrodes was performed, focusing on key properties. The incorporation of porphyrin into the polymer matrix was confirmed by UV-Vis and IR characterization. SEM micrographs showed the morphological changes induced by the codopant. Cyclovoltammetry was used to evaluate the conductivity of the film, its electroactivity, electroactive area and HOMO energy level. The chopped chronoamperometry confirmed the photoactivity of the material and its stability for 3000 s. The electrical and optical properties of the polymer were characterized by EIS and light absorption measurements to propose its energy level diagram. The PPy/TCPP coatings were obtained with high homogeneity on FTO, good conductivity, quasi-reversible electrochemical activity to ferrocene probe and stable photoactivity. Electrical characterization indicates high charge flow under illumination. An indirect bandgap of 2.51 eV and a HOMO level value of -4.59 eV were obtained for PPy/TCPP.

Directing the photogenerated charge flow in a photocathodic metal protection system with single‐domain ferroelectric PbTiO3 nanoplates

AbstractPhotocathodic protection (PCP) is arguably an ideal alternative technology to the conventional electrochemical cathodic protection methods for corrosion mitigation of metallic infrastructure due to its eco‐friendliness and low‐energy‐consumption, but the construction of highly‐efficient PCP systems still remains challenging, caused primarily by the lack of driving force to guide the charge flow through the whole PCP photoanodes. Here, we tackle this key issue by equipping the PCP photoanode with ferroelectric single‐domain PbTiO3 nanoplates, which can form a directional “macroscopic electric field” throughout the entire photoanode controllable by external polarization. The properly poled PCP photoanode allows the photogenerated electrons and holes to migrate in opposite directions, that is, electrons to the protected metal and holes to the photoanode/electrolyte interface, leading to largely suppressed charge annihilation and consequently a considerable boost in the overall solar energy conversion efficiency of the PCP system. The as‐fabricated photoanode can not only supply sufficient photocurrent to 304 stainless steel to initiate cathodic protection, but also shift the metal potential to the corrosion‐free range. Our findings provide a viable design strategy for future high‐performance PCP systems based on ferroelectric nanomaterials with enhanced charge flow manipulation.

Kinetic and thermodynamic approach to precisely solve the unsteady Rayleigh flow problem of a rarefied homogeneous charged gas under external force influence

Abstract An extension and further development of our previous article [J. Non-equilibrium Thermodyne. 37 (2012), 119–141] is presented. We study the irreversible non-equilibrium thermodynamics (INT) properties of the exact solution to the dilute homogeneously charged gas problem with unsteady Rayleigh flow. In contrast to previous research, the charged gas flows under the influence of an external force, the flat plate oscillates, and the displacement current term is considered, leading to significant advancements in understanding natural plasma dynamics. We are solving the Boltzmann kinetic equation (BKE) Krook model supplemented by Maxwell’s equations. We used a travelling wave and moments method with an electron velocity distribution function (EVDF). To the best of our knowledge, as three new scientific achievements, we introduced a new mathematical model for calculating the thermodynamic forces, kinetic coefficients, and fluxes variables, Equations (28–40) and (50–54). Second, we determined, with reasonable accuracy, the thermodynamic equilibrium time of electrons, t equ = 26.7955, under an external force. We clarify the difference between equilibrium EVDF and perturbed EVDF and take advantage of BKE to account for non-equilibrium thermodynamic principles. For diamagnetic and paramagnetic plasmas, the extended Gibbs equation predicts ratios between various contributions to the internal energy change (IEC) is presented. A standard laboratory argon plasma model is used to apply the results.

Understanding the Electronic Structure and Chemical Bonding in the 2D Fullerene Monolayer.

Recently synthesized two-dimensional (2D) monolayer quasi-hexagonal-phase fullerene (qHPC60) demonstrates excellent thermodynamic stability. Within this monolayer, each fullerene cluster is surrounded by six adjacent C60 cages along an equatorial plane and is connected by both C-C single bonds and [2 + 2] cycloaddition bonds that serve as bridges. In this study, we investigate the stability mechanism of the 2D qHPC60 monolayer by examining the electronic structure and chemical bonding through state-of-the-art theoretical methodologies. Density functional theory (DFT) studies reveal that 2D qHPC60 possesses a moderate direct electronic band gap of 1.46 eV, close to the experimental value (1.6 eV). It is found that the intermolecular bridge bonds play a crucial role in enhancing the charge flow and redistribution among C60 cages, leading to the formation of dual π-aromaticity within the C60 sphere and stabilizing the 2D framework structure. Furthermore, we identify a series of delocalized superatom molecular orbitals (SAMOs) within the 2D qHPC60 monolayer, exhibiting atomic orbital-like behavior and hybridization to form nearly free-electron (NFE) bands with σ/π bonding and σ*/π* antibonding properties. Our findings provide insights into the design and potential applications of NFE bands derived from SAMOs in 2D qHPC60 monolayers.

Analysis of charged particle flows in the interelectrode gap of an ion-optical system

Analysis of charged particle flows in the interelectrode gap of an ion-optical system

The Symmetric Dual Inductor Hybrid Converter for Direct 48V-to-PoL Conversion

This work introduces the symmetric dual inductor hybrid (SDIH) dc-dc converter topology, which is suitable for large conversion ratios where regulation is required, such as direct 48 V to point-of-load (PoL) applications. A dickson-type switched capacitor network is used to effectively produce two interleaved PWM outputs with a greatly reduced voltage amplitude relative to the input voltage, allowing the subsequent magnetic volume to be reduced while retaining modest switching frequencies. Distinct from related variations, part count is significantly reduced while both even and odd order switched capacitor networks can be used with straightforward split-phase control; allowing either network type to achieve complete soft-charging of all flying capacitors. Additionally, charge flow is uniformly distributed through all elements, with equal capacitor and inductor values being preferred. Subsequently this topology is expected to simplify component selection, improve electrical and thermal performance, and reduce cost. Furthermore, analysis is presented that calculates precise phase durations without making small ripple assumptions, revealing up to a 75% timing error in cases where either inductor or capacitor ripple is ignored. Finally, a discrete prototype validates this analysis and demonstrates very high measured power densities of 1,029 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> , 754 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> , and 663 W/in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{3}$</tex-math></inline-formula> for 48 V input and regulated output voltages of 3 V, 2 V, and 1 V, respectively, while switching at a frequency of 750 kHz.

Full-Space Electric Field in Mo-Decorated Zn2In2S5 Polarization Photocatalyst for Oriented Charge Flow and Efficient Hydrogen Production.

Integration of photocatalytic hydrogen (H2) evolution with oxidative organic synthesis presents a highly attractive strategy for the simultaneous production of clean H2 fuel and high-value chemicals. However, the sluggish dynamics of photogenerated charge carriers across the photocatalysts result in low photoconversion efficiency, hindering the wide applications of such a technology. Herein, this work overcomes this limitation by inducing the full-space electric field via charge polarization engineering on a Mo cluster-decorated Zn2In2S5 (Mo-Zn2In2S5) photocatalyst. Specifically, this full-space electric field arises from a cascade of the bulk electric field (BEF) and local surface electric field (LSEF), triggering the oriented migration of photogenerated electrons from [Zn-S] regions to [In-S] regions and eventually to Mo cluster sites, ensuring efficient separation of bulk and surface charge carriers. Moreover, the surface Mo clusters induce a tip enhancement effect to optimize charge transfer behavior by augmenting electrons and proton concentration around the active sites on the basal plane of Zn2In2S5. Notably, the optimized Mo1.5-Zn2In2S5 catalyst achieves exceptional H2 and benzaldehyde production rates of 34.35 and 45.31mmol gcat -1 h-1, respectively, outperforming pristine ZnIn2S4 by 3.83- and 4.15-fold. These findings mark a significant stride in steering charge flow for enhanced photocatalytic performance.

Modulating charge storage mechanism of cobalt-tungsten nitride electrodes using in situ formed metal-p-n heterojunction for ultrahigh energy density supercapattery

Supercapatteries combine both diffusion-controlled and capacitive charge storage mechanisms to simultaneously deliver exceptional power density and energy density. Though developing materials that combine both charge storage mechanisms for use as supercapattery electrodes is difficult, one solution has been to modify a material that inherently has one of these mechanisms so that it also exhibits the other form of charge storage. In the present study, we modulate the electrochemical reconstruction of a W5N4 electrode to modify its charge storage from pure battery-type to pseudocapacitive, thus enhancing its specific capacity and cyclic stability. This modulation was carried out by embedding Co in W5N4 (Co-W5N4), leading to the formation of W and N-doped Co(OH)2 as an active phase and producing a high specific capacity of 2211 C g−1 at 2 A g−1. The incorporation of a thin layer of TiO2 (Co-W5N4/TiO2) through atomic layer deposition minimized tungsten dissolution during reconstruction, thus generating in-situ a dynamic metal–p-n junction heterostructure (Co-W5N4||Co(OH)2||TiO2) that modulated the charge flow, achieving high-rate capability (retaining 53.1 % at 50 A g−1 compared to 2 A g−1) and cyclic stability (82.8 % after 100,000 cycles at a high current density of 40 A g−1). As illustrated by operando electrochemical impedance spectroscopy and physicochemical analysis, the dynamic response of metal–p-n junction sustains the pseudocapacitive charge storage mechanism at high current rate. This study thus demonstrates the formation of metal-p-n heterojunction and describes its dynamic response under actual charge/discharge operating conditions, providing useful information for the design of energy storage electrodes and energy conversion catalysts.

Ambiguities in Decomposing Molecular Polarizability into Atomic Charge Flow and Induced Dipole Contributions.

The molecular dipole polarizability can be decomposed into components corresponding to the charge flow between atoms and changes in atomic dipole moments. Such decompositions are recognized to depend on how atoms are defined within a molecule, as, for example, by Hirshfeld, iterative Stockholder, or quantum topology partitioning of the electron density. For some of these, however, there are significant differences between the numerical results obtained by analytical response methods and finite field calculations. We show that this difference is due to analytical response methods accounting for (only) the change in electron density by a perturbation, while finite field methods may also include a component corresponding to a perturbation-dependent change in the definition of an atom within a molecule. For some atom-in-molecule definitions, such as the iterative Hirshfeld, iterative Stockholder, and quantum topology methods, the latter effect significantly increases the charge flow component. The decomposition of molecular polarizability into atomic charge flow and induced dipole components thus depends on whether the atom-in-molecule definition is taken to be perturbation-dependent.

Nonconjugated Polymers Enabled Solar Water Oxidation.

Wholly distinct from conjugated polymers which are featured by generic charge transfer capability stemming from a conjugated molecular structure, solid nonconjugated polymers mediated charge transport has long been deemed as theoretically impossible because of the deficiency of π electrons along the molecular skeleton, thereby retarding their widespread applications in solar energy conversion. Herein, we first conceptually unveil that intact encapsulation of metal oxides (e.g., TiO2, WO3, Fe2O3, and ZnO) with an ultrathin nonconjugated polyelectrolyte of branched polyethylenimine (BPEI) can unexpectedly accelerate the unidirectional charge transfer to the active sites and foster the defect generation, which contributes to the boosted charge separation and prolonged charge lifetime, ultimately resulting in considerably improved photoelectrochemical (PEC) water oxidation activities. The interfacial charge transport origins endowed by BPEI adornment are elucidated, which include acting as a hole-withdrawing mediator, promoting vacancy generation, and stimulating the directional charge flow route. We additionally ascertain that such charge transport characteristics of BPEI are universal. This work would unlock the charge transfer capability of nonconjugated polymers for solar water oxidation. The nonconjugated insulating polymer was utilized as a charge transport mediator for boosting charge migration and separation over metal oxides toward solar water oxidation.

Steering charge flow in hierarchical ZnIn2S4/TiO2/Ti3C2 heterojunction for noble-metal-free photocatalytic hydrogen production

The construction of effective photogenerated charge transfer channels through interface engineering is the key to achieving the highly efficient of photocatalysts. Herein, sandwich-like ZnIn2S4/TiO2/Ti3C2 nanosheets integrated type-II heterostructure with Schottky junction are reasonably fabricated by low temperature in-situ growth method. Benefitting from the intensive visible light absorption of ZnIn2S4, the fast electron transport of TiO2, the rich active sites in Ti3C2, as well as the intimate interface coupling and the matched band alignment among ternary components, enhanced hydrogen production can be achieved with ZnIn2S4/TiO2/Ti3C2 hierarchical photocatalyst under visible light irradiation in the absence of noble metal co-catalysts. The concept of coupling type-II heterostructure with the Schottky barrier can steer the charge flow and boost the charge carrier separation and transfer across the interfacial domain, which may spark new ensemble design for efficient solar energy harvesting and conversion.

Sonication supported green modulation of Fe:MoO3/g-C3N4 heterojunction as solar light sensitive photocatalyst for dye degradation and photoelectrochemical water splitting

The concerns of dye in an aquatic system associated with acute toxicity and carcinogenicity, and the increase in demand for hydrogen production has led to a keen interest in advancing solar driven methodologies utilizing potent photocatalysts to address environmental concerns through sustainable remediation practices. In this pursuit, we synthesized a heterostructure comprised of Fe doped MoO3 (Fe:MoO3), anchored on g-C3N4 sheet as a photocatalyst denoted as Fe:MoO3/g-C3N4, employing a sonication supported green synthesis method with the aid of Murraya paniculata leaf extract. We explored structural, morphological, and surface characteristics using various analytical techniques, including X-Ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV–visible spectroscopy, Field emission scanning electron microscopy (FE-SEM) and High-resolution transmission electron microscopy (HR-TEM), X-Ray photoelectron spectroscopy, and BET for a comprehensive surface analysis. The outcomes highlighted the exquisitely oriented and interconnected arrangement of MoO3 nano rods ensconced within a piled layer of g-C3N4. The XRD patterns unveiled the coexistence of g-C3N4 and Fe:MoO3 within the heterojunction structure. FESEM and HRTEM image analysis of Fe:MoO3/g-C3N4 heterojunction reveals a g-C3N4 nanosheet wrapping the Fe:MoO3 nanoparticles with the formation of nanorods of MoO3 with an average thickness of 9.46 nm containing circular Fe nanoparticles with a mean diameter of 8.97 nm. This intricate configuration resulting in a decrease of the size of the nanoparticle caused by effective sonication-supported green modulation configuration facilitated an optimized charge flow, contributing to the elevated photo assisted catalytic performance of the heterojunction. The Fe:MoO3/g-C3N4 semiconductor heterojunction exhibited a considerable surface area and pore volume, inherently amplifying the sites of the activity on the surface and thereby enhancing photoactivity. As opposed to both g-C3N4 and the Fe:MoO3 nanoparticles, the Fe:MoO3/g-C3N4 semiconductor heterojunction showcased enhanced photocatalytic effectiveness in the degradation of dye Crystal violet (CV). Under optimized circumstances, the photo assisted degradation of dye CV by the semiconductor heterojunction adhered to pseudo-first-order kinetics. The active species responsible for the photo assisted degradation process is identified as •O2−. These findings not only emphasize the enhanced efficacy of the developed semiconductor heterojunction but also reveal its potential for addressing the environmental challenges posed by dye CV contamination through prolonged and efficient photocatalytic remediation practices. A marked improvement in both photo assisted catalytic and photoelectrochemical (PEC) water splitting activities under visible light exposure was showcased. The augmented performance of the Fe:MoO3/g-C3N4 semiconductor heterojunction in photodegradation and PEC water splitting activities can be attributed to the extended absorption of visible light. Additionally, the synergistic influence of g-C3N4, contributes positively to the separation of charges and expedites the transfer efficiency of photogenerated charge carriers. This synergy enhances the overall effectiveness of the nanoparticles in harnessing visible light for efficient water-related processes.

Unveiling the role of Atomic-Level “Pump-Driven” effect in MoS2/MnO2 for facilitating directional charge transfer in hybrid capacitive deionization

In addressing the limitations imposed by the inherently low electronic conductivity and substantial ion transfer resistance of transition metal oxides (TMOs) in hybrid capacitive deionization (HCDI) applications, this study delineates a pioneering approach through the fabrication of a MoS2/MnO2 heterostructure, leveraging manganese dioxide (MnO2) as a model system. The investigation underscores the essentiality of constructing high-quality interfaces to act as conduits for directional charge flow, a critical but formidable challenge for enhancing desalination efficacy in electrode materials. By harnessing an atomistic “pump-driven” mechanism, the MoS2/MnO2 heterostructure demonstrably facilitates the promotion of desalination processes, underscored by the establishment of a potent local electric field (IEF) aimed at commanding charge dynamics. Empirical and computational analyses coalesce to unveil the preferential electron transfer from MoS2 to MnO2, a phenomenon precipitated by charge redistribution. This orchestrated charge flow not only augments electronic and ionic transfer efficiencies but also emboldens the MoS2/MnO2 heterostructure with enhanced desalination capabilities. The results show that MoS2/MnO2 demonstrates superior HCDI performance compared to MnO2 in a 500 mg L-1 NaCl solution at 1.2 V, with SRC of 33.21 mg g-1 and SRR of 1.50 mg g-1 min-1. The elucidation of this charge-guided dynamic, achieved through meticulous manipulation of the electronic microstructure and the IEF at the atomic scale, presents a novel paradigm for material science. This research presents an innovative approach for realizing robust charge-guided dynamics through the deliberate manipulation of the electronic microstructure and IEF of materials, employing an atomic-level “pump-driven” effect. This strategy opens new avenues for extending these principles to a broad array of advanced materials.

Design of an Intelligent Energy Management System for Electric Vehicle Charging Station

In today’s world there are more outcomes in environmental change due to the overutilization of petroleum products in this manner prompting a genuine effect on the climate. So there is a need for a substitute answer for lessen the consumption of such non – sustainable assets. One such exertion made in the field of Freeways is the advancement of "Solar Freeways" which can be an elective arrangement. Sun oriented streets consolidate various arrangements in one – it can assist us with improving the creation of power utilizing sun based boards, to give a computerized stage to our future country's ventures like Smart Cities, and to work with the arising electric vehicles that supplant the petroleum driven vehicles and substantially more. Motivated by the fact that there are numerous amount of clean and sustainable energy we receive from roadways, the following study puts forward some of the event and application of an innovative charging method for the renewable energy driven electric cars, buses by using the roadway and also implementation of revolutionary nanotechnology along with the latest best in the house power electronics and power system analysis tools. A small scale prototype model was made by our team to attest the working of smart inductive charging process. Our project team was successful to improve the working of the model by improving the use of the preinstalled solar panels and also implement its use on the very concept we are trying to improve. On the vehicle, there will be the use of coils which are experimentally made for the flow of charges that are needed to provide charge to a moving electric vehicle (EV). The detailed strategy is presented in this report. Key Words: Environmental change, Overutilization of petroleum products, Solar Freeways, Renewable energy, Electric vehicles (EVs), Smart Cities, Nanotechnology

Eliminating the channel resistance in two-dimensional systems using viscous charge flow

Driven by the pursuit of high-performance electronic devices and the exploration of quantum phenomena, research into two-dimensional (2D) systems and materials, has unveiled their exceptional properties and potential applications. While extensive efforts have centered on minimizing contact resistance, reducing the intrinsic channel resistance within the conducting material remains a formidable challenge. Research in this direction has focused on investigating superconductivity and ballistic transport. However, the practical applications of these phenomena are usually constrained by the requirement for cryogenic conditions. Charge transport in the hydrodynamic regime emerges as a versatile alternative, offering enhanced resilience to these challenges, and making it a promising avenue for effectively reducing channel resistance in 2D systems. The current perspective delves into charge hydrodynamics, exploring its mechanisms, recent advancements, enduring challenges, and its potential in reducing the channel resistance.

Understanding the interactions between anticancer active molecules Cp2TiCl2 and Cp2VCl2 and E@Al12 (E = C, Si) clusters using density functional theory calculations

This work investigated the interaction between E@Al12 (E = C, Si) clusters and titanocene dichloride (TDC) and vanadocene dichloride (VDC) anticancer drugs using BP86. Corrected interaction energy values of the complexes were computed. Interaction effect on the frontier orbital energy values of the pure nano-cluster and drugs were illustrated. Also, electrophilicity-based charge transfer (ECT) was indicated charge flow from anticancer drug to nano-cluster. Cl⋅⋅⋅Al weak non-covalent interactions in the studied systems were explored with Independent gradient model analysis based on Hirshfeld partition of molecular density (IGMH) and Non-covalent interaction (NCI). QTAIM analysis was considered to exploring of bond critical point of Al…Cl.

Tailoring Charge Flow in Carbon-Defective Cu-MOF with Pd Nanoparticles: A Boost for Visible Light Organic Photoelectrochemical Transistor in Bioanalysis.

The photoactive material was of significant importance in organic photoelectrochemical transistor (OPECT) bioanalysis as it influences the photoinduced voltage and the μC* product, resulting in a varying sensor sensitivity. The utilization of metal-organic frameworks (MOFs) as photoactive materials in OPECT analysis is promising, yet it remains a grand challenge due to the inherently narrow light absorption range and high electron-hole recombination rate. Herein, Pd NPs were encapsulated as electron acceptors into the Cu-MOF using a double-solvent method, followed by pyrolysis at the proper temperature. After pyrolysis, Cu-MOF transformed into a carbon defect-rich composite of CuO and Cu2O while retaining its high porosity and structural morphology. The resulting carbon defect-rich pyrolysis Cu-MOF (p-Cu-MOF) served as an active support, facilitating the separation of electrons and holes. The photoelectrons trigger the electron transfer of adjacent active metal components and the formation of a Schottky junction between Pd and the MOFs. This effect induces the electron donation from the MOFs. Moreover, Pd/pyrolysis Cu-MOF exhibits significantly higher visible light absorption, better water stability, and higher electrical conductivity compared to Cu-MOF and Pd/Cu-MOF. An OPECT sensor was fabricated by utilizing Pd/p-Cu-MOF as the photoactive material and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the channel material on an integrated laser-etched FTO. The aptamer was used as the recognition element, enabling sensitive and efficient detection of residual isocarbophos.

Analysis of Charge and Current Flow in the LCR Series Circuit via Chebyshev Wavelets

In this research paper, an investigation of charge and current flow in an LCR series circuit has been presented. For this purpose, basis functions of Chebyshev wavelets of the second kind have been utilized. The proposed method involves representing the highest-order derivatives as a series of basis functions using Chebyshev wavelets. In order to demonstrate the effectiveness of this approach, numerical examples have been provided, and their results are presented to show the accuracy of the proposed scheme.