Charge Transfer Parameters Research Articles

Photoinduced charge transfer assisted through external electric field and ternary hydrogen bonding strategies

Understanding the mechanisms governing interfacial charge transfer in photoactive layer is crucial for optimizing photogenerated charge separation efficiency. In this study, the interfacial charge transfer process is regulated by applying external electric field (Fext) and ternary hydrogen bonding strategies. We observe significant changes in the excited state properties and charge transfer parameters at the interface under Fext conditions. This facilitates an in-depth exploration of the effects of Fext on the microscopic details of the interface at the molecular level. Implementing the ternary hydrogen bonding strategy significantly enhances the electron-attracting ability of fullerene. Comparative analysis of the PTB7-Th:PC71BM and PTB7-Th:C7:PC71BM systems under Fext = 0, reveals that the ternary hydrogen bonding strategy increases the charge transfer pathway and significantly improves the intermolecular charge separation rate (KCS). Additionally, we evaluated the relationship between hydrogen bond strength and Fext, demonstrating that Fext significantly enhances the hydrogen bond strength between C7:PC71BM. These studies provide deeper insights into the role of Fext and ternary hydrogen bonding strategies in charge transfer process, providing a valuable theoretical framework for designing more efficient organic solar cells (OSCs).

Aluminum and Mild Steel Inhibition Investigation Using Trithiocyanuric Acid: Insights from Density Functional Theory (DFT)

<p>The study investigates the corrosion inhibition properties of Trithiocyanuric Acid (TTCA) on Aluminum and mild steel using Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations. The electronic properties of TTCA, including the highest occupied molecular orbital (E<sub>HOMO</sub>) of -7.617 eV and the lowest unoccupied molecular orbital (E<sub>LUMO</sub>) of -4.301 eV, yield an energy gap of 3.316 eV. The calculated absolute electronegativity was 5.959 eV, global hardness obtained was 1.658 eV, global softness was 0.603136 eV, global electrophilicity index was 1.449891 eV, and nucleophilicity was 0.689707 eV. The energy of back donation was also 0.689707 eV. The charge transfer parameters, ΔNFe and ΔNAl, are also 0.862989 eV and -0.21653 eV, respectively, indicating effective interaction with both metal surfaces. Functional groups in TTCA contribute significantly to its corrosion inhibition performance by facilitating alignment on the metal surfaces. The interaction mechanism is characterized as physisorption, with binding energy values falling within the range typical for this adsorption type. The results suggest that TTCA is a suitable corrosion inhibitor for Aluminum and mild steel, making it a promising molecule for industrial applications where metal protection is essential.</p>

Tailoring optical and photocatalytic properties of sulfur-doped boron nitride quantum dots via ligand functionalization

Boron nitride quantum dots (BNQDs) have emerged as promising photocatalysts due to their excellent physicochemical properties. This study investigates strategies to enhance the photocatalytic performance of BNQDs through sulfur-doping (S-BNQDs) and edge-functionalization with ligands (urea, thiourea, p-phenyl-enediamine (PPD)). To analyze the geometry, electronic structure, optical absorption, charge transfer, and photocatalytic parameters of pristine and functionalized S-BNQDs, we performed density functional theory calculations. The results showed that S-doping and ligand functionalization tune the bandgap, band energies, and introduce mid-gap states to facilitate light absorption, charge separation, and optimized energetics for photocatalytic redox reactions. Notably, the PPD ligand induced the most substantial bandgap narrowing and absorption edge red-shift by over 1 electron volt (eV) compared to pristine S-BNQD, significantly expanding light harvesting. Additionally, urea and PPD functionalization increased the charge transfer length by up to 2.5 times, effectively reducing recombination. On the other hand, thiourea functionalization yielded the most favorable electron injection energetics. The energy conversion efficiency followed the order: PPD (15.0%) > thiourea (12.0%) > urea (11.0%) > pristine (10.0%). Moreover, urea functionalization maximized the first-order hyperpolarizability, enhancing light absorption. These findings provide valuable insights into tailoring S-BNQDs through strategic doping and functionalization to develop highly efficient, customized photocatalysts for sustainable applications.

Novel cyano functional small molecule photosensitizers with amplified electron injection and photovoltaic attributes: molecular modelling towards efficient dye‐sensitized solar cells

AbstractBACKGROUNDThe exploration of novel photosensitizers with reverberant optoelectronic features for dye‐sensitized solar cells (DSSCs) is a frontline area of research. In this respect, attempts have been made to design a series of novel organic dyes (JFK‐1–JFK‐10) with D‐π‐A framework by π‐spacer modification strategy. The suitability of developed sensitizers for DSSCs applications is confirmed by executing natural bond orbital (NBO) analysis, transition density matrix (TDM) analysis, frontier molecular orbital (FMO) analysis, density of state (DOS) analysis, binding energy (Eb), electron regeneration energy (ΔGreg), free energy of injection (ΔGinject), electronic coupling constant (VRP), and intramolecular charge transfer (ICT) parameters qCT (e‐), DCT (Å), H index (Å), ∆(Å), t index (Å), μCT (D).RESULTSThe calculated results of these analyses show that replacing the thiophene (B0) π‐spacer with extended conjugated thiazole and thiophene as a π‐spacer (B1‐B10) results in significantly lowered FMO energy levels, broader λmax values, and ICT parameters respectively. All the proposed dyes could be used as excellent sensitizers for DSSCs; the B9 spacer in JFK‐9 makes JFK‐9 a highly efficient candidate for the high‐efficiency of DSSCs due to promising photovoltaic characteristics, like the reduced Egap (4.386 eV), longer λmax(427.989 nm), longer excited state lifetimes (1.483 ns), a lower ΔGreg (1.807 eV), a greater dipole moment of (9.475 D), and large qCT (0.546), LHE (0.981), and eVOC (1.729 eV).CONCLUSIONThe fabricated dyes’ (F1‐F9) photoelectronic and chemical transfer parameters near the titania‐electrolyte interface (dyes@TiO2) proved have better accumulation and recombination of dyes@TiO2 model. The adsorption energies calculated of all compounds provide a deep insight into adsorption and charge transfer to a semiconductor TiO2 conduction band. Hence, these modeled dyes (JFK‐1‐JFK‐10) could be used as efficient DSSCs and open new avenues for researchers to synthesize high‐performance DSSCs. © 2024 Society of Chemical Industry (SCI).

Constructing Mixed Density Functionals for Describing Dissociative Chemisorption on Metal Surfaces: Basic Principles.

The production of a majority of chemicals involves heterogeneous catalysis at some stage, and the rates of many heterogeneously catalyzed processes are governed by transition states for dissociative chemisorption on metals. Accurate values of barrier heights for dissociative chemisorption on metals are therefore important to benchmarking electronic structure theory in general and density functionals in particular. Such accurate barriers can be obtained using the semiempirical specific reaction parameter (SRP) approach to density functional theory. However, this approach has thus far been rather ad hoc in its choice of the generic expression of the SRP functional to be used, and there is a need for better heuristic approaches to determining the mixing parameters contained in such expressions. Here we address these two issues. We investigate the ability of several mixed, parametrized density functional expressions combining exchange at the generalized gradient approximation (GGA) level with either GGA or nonlocal correlation to reproduce barrier heights for dissociative chemisorption on metal surfaces. For this, seven expressions of such mixed density functionals are tested on a database consisting of results for 16 systems taken from a recently published slightly larger database called SBH17. Three expressions are derived that exhibit high tunability and use correlation functionals that are either of the PBE GGA form or of one of two limiting nonlocal forms also describing the attractive van der Waals interaction in an approximate way. We also find that, for mixed density functionals incorporating GGA correlation, the optimum fraction of repulsive RPBE GGA exchange obtained with a specific GGA density functional is correlated with the charge-transfer parameter, which is equal to the difference in the work function of the metal surface and the electron affinity of the molecule. However, the correlation is generally not large and not large enough to obtain accurate guesses of the mixing parameter for the systems considered, suggesting that it does not give rise to a very effective search strategy.

Hexagonal mesoporous silica/perovskite oxides composites as unique scattering layers in photoelectrodes of high performance dye-sensitized photovoltaics

As the photoactive TiO2 film in dye-sensitized solar cells (DSSCs) is transparent to incident light owing to its nano-sized particles, the efficiency may be affected by the light loss. Therefore, light scattering layers including CeMnO3, CeFeO3, CeSnO3, CeZnO3, 3D-hexagonal mesoporous silica (HMS-3), and HMS-3:CeMnO3 composites were deposited on TiO2 layer by doctor blade technique in order to harvest more sunlight. To characterize each material, XRD, FTIR, PL, DRS, FESEM, EDS, and BET analyses were investigated. In addition, dye absorption capacity, power conversion efficiency (PCE), open-circuit voltage decay (OCVD), and charge transfer parameters were assessed. According to photovoltaic data, TiO2/50 wt% HMS-3+50 wt% CeMnO3 based DSSC brought about the maximum PCE of 7.47% with fill factor (FF), short-circuit current density (Jsc), and open-circuit voltage (Voc) of 0.48, 21.17 mA/cm2, and 0.738 V, respectively, displaying 75.4% higher PCE compared to solar cell fabricated by TiO2 (PCE = 4.26%, Jsc = 11.72, Voc = 0.685 V, FF = 0.53). The champion 50 wt% HMS-3+50 wt% CeMnO3 composite featured large particles with high porosity, which could enhance light scattering and cause the light path to be longer, based on the Mie theory. Moreover, because of the big surface area (643.80 m2/g), large pore volume (0.4282 cm3/g), and appropriate N719 dye loading of the champion 50 wt% HMS-3+50 wt% CeMnO3 composite, more dye molecules were excited, and the number of light-generated electrons was boosted, elevating the current density, facilitating faster charge transfer from the TiO2 photoanode towards the Pt electrode, and limiting electron-hole recombination to a high extent, which led to an enormous improvement in efficiency.

A computational insight into enhancement of photovoltaic properties of non-fullerene acceptors by end-group modulations in the structural framework of INPIC molecule

Improving the open circuit voltage is a major challenge for enhancing the overall efficiency of organic solar cells. Current work has concentrated on improving open-circuit voltage by designing new molecular frameworks from an INPIC molecule having a conjugated fused core. We modulated the structure by changing the terminal groups of the reference molecule (INPIC) with seven strong electron-withdrawing units. We investigated various optoelectronic attributes, charge transfer, and photovoltaic and geometrical parameters by compiling the B3LYP/6-31G(d,p) functional of the DFT approach. The optical absorption for modulated molecules ranges from 748.51 nm to 845.96 nm while showing higher oscillation strength than INPIC. At the same time, their impressive charge transport is attributed to their smaller excitation and exciton binding energy, higher electron/hole mobility, narrower band gap, and a more than 99 % intramolecular charge transfer. The larger dipole moments help in the dense interaction of acceptors with employed donor J61 which, in turn, improves charge transfer at the donor-acceptor interface. One of the triumphs that are difficult to get in organic molecules is success in achieving a higher open circuit voltage (VOC). Our conceptualized molecular frameworks of acceptors are featured with a notable VOC improvement in the range of 1.84–2.05 eV. Thus, the results of the current investigation pave the root for architecting the acceptor molecules with impressive optoelectrical properties that may be capable of providing high photovoltaic output. Thus these acceptors can be utilized for the development of advanced organic solar cells in future.

Exploring the effect of electric field on charge-transfer states at non-fullerene D/A interface

Using Marcus theory, the electric-field-dependent charge-separation dynamics of non-fullerene acceptors D/A heterojunctions are simulated. On the D/A interface, the excited-state characteristics show obvious differences under different electric field intensities, providing microscopic details of the non-fullerene D/A interface at the atomic level. For different electric field conditions, so the calculated reorganization energy ranges from 0.97 to 1 eV. By comparing other charge transfer parameters of this system, it was found that the reorganization energy mainly determines the charge-transfer rate. The results show that the charge transfer rate does exhibit a variation that depends on the electric field intensity and is consistent with the variation in the Marcus inverted region. By evaluating the rate of charge separation/recombination, it is judged that its charge separation shows significant advantages, and the trifurcated structure of the molecule also provides multiple charge transfer paths for charge separation, which contributes to the charge generation mechanism.

Dynamic Effects on Hole Transport in Amorphous Organic Semiconductors: a Combined QM/MM and kMC Study.

Small-molecule-based amorphous organic semiconductors (OSCs) are essential components of organic photovoltaics and organic light-emitting diodes. The charge carrier mobility of these materials is an integral and limiting factor in regard to their performance. Integrated computational models for the hole mobility, taking into account structural disorder in systems of several thousand molecules, have been the object of research in the past. Due to static and dynamic contributions to the total structural disorder, efficient strategies to sample the charge transfer parameters become necessary. In this paper, we investigate the impact of structural disorder in amorphous OSCs on the transfer parameters and charge mobilities in different materials. We present a sampling strategy for incorporating static and dynamic structural disorder which are based on QM/MM methods using semiempirical Hamiltonians and extensive MD sampling. We show how the disorder affects the distributions of HOMO energies and intermolecular couplings and validate the results using kinetic Monte Carlo simulations of the mobility. We find that dynamic disorder causes an order of magnitude difference in the calculated mobility between morphologies of the same material. Our method allows the sampling of disorder in HOMO energies and couplings, and the statistical analysis enables us to characterize the relevant time scales on which charge transfer occurs in these complex materials. The findings presented here shed light on the interplay of the fluctuating amorphous matrix with charge carrier transport and aid in the development of a better understanding of these complex processes.

Designing photoelectrode architecture modified with mesoporous MCM-41/CeO2 composites as specific scattering layers for dye-sensitized solar cells

Depositing light scattering film on top of the photoactive layer of dye-sensitized solar cells (DSSCs) is one method to boost the device efficiency. Therefore, mesoporous MCM-41 and CeO2 were prepared and coated on TiO2 photoactive layer in both their pure and composite (1–4 wt% CeO2:MCM-41) forms by doctor blade technique. XRD, FESEM, EDS, TEM, BET, FTIR, DRS, and PL analyses were employed to characterize all compounds. Additionally, the power conversion efficiency (PCE), dye adsorption capacity, and charge transfer parameters of various DSSCs were measured. The data taken from J-V plots indicated that the highest conversion efficiency belonged to 2 wt% CeO2:MCM-41 when was used as the scattering layer which could boost the efficiency up to 7.42% with fill factor (FF), open-circuit voltage (Voc) and short-circuit current density (Jsc), respectively, equal to 0.48, 0.752 V, 20.55 mA.cm−2, confirming 78.8% greater efficiency than the bare TiO2 containing DSSC (PCE = 4.15%, FF = 0.39, Voc = 0.736 V, Jsc = 14.45 mA.cm−2). In fact, once 2 wt% CeO2:MCM-41 with large particles was applied, according to Mie's theory, prolonged the light path through incident light scattering, which resulted in more light harvesting by photoanode material, further dye molecules excitation, and improvement in the current density. Also, because of the insulating nature of silica material in 2 wt% CeO2:MCM-41 layer, it reduced the charge recombination process and accelerated the transfer of electrons from the TiO2 photoanode to the Pt counter electrode via the external circuit. Besides, high porosity and huge surface area (757.34 m2/g) of 2 wt% CeO2:MCM-41 promoted dye molecules to be adsorbed additionally which generated extra photoelectrons.

Theoretical investigation for dye-sensitized solar cells: effect of donor variation on the optoelectronic properties and charge transfer parameters

Theoretical investigation for dye-sensitized solar cells: effect of donor variation on the optoelectronic properties and charge transfer parameters

Charge-Separated States Determined Photoinduced Electron Transfer Efficiency in a D-D-A System in an External Electric Field

Focusing on the photoinduced electron transfer properties of the D-D-A molecule ((TPA-TT)-BODIPY-C60) in an external electric field (Fext), the excited-state properties in which the double-donor molecule is excited to form three charge-separated states were simulated. The charge-transfer processes of these three charge-separated states were investigated by considering the two donors as a whole ((TPA-TT-BODIPY)·+-C60·–) as a comparison object. The electronic coupling (VDA), reorganization energy (λ), and free energy (ΔG) of the different charge-separated states in Fext were calculated and simulated. The calculated results show that the λ of (TPA-TT-BODIPY)·+-C60·– ranges from 0.576 to 0.51 eV, and the calculated ΔG of exciton dissociation ranges from −1.402 to −1.143 eV, indicating that exciton dissociation occurs in the Marcus inverted region. In the range of Fext = −10 × 10–5 to 10 × 10–5 au, the trend of the charge-transfer rate is gradually increasing, and the rate increase is mainly from the VDA and ΔG changes. Moreover, the rapid formation of the (TPA-TT)-BODIPY·+-C60·– charge-separated state and the formation of the long-lived (TPA-TT)·+ -BODIPY-C60·– are indicated by the exciton dissociation rate. By studying the charge-transfer parameters under different electric field directions, it is found that the regulation of electric field strength on the charge-transfer rate is consistent. These results provide a feasible method for the rational design of a new type of electron transfer process with high efficiency of the D-D-A system.

Understanding molecular and electrochemical charge transfer: theory and computations.

Electron, proton, and proton-coupled electron transfer (PCET) are crucial elementary processes in chemistry, electrochemistry, and biology. We provide here a gentle overview of retrospective and currently developing theoretical formalisms of chemical, electrochemical and biological molecular charge transfer processes, with examples of how to bridge electron, proton, and PCET theory with experimental data. We offer first a theoretical minimum of molecular electron, proton, and PCET processes in homogeneous solution and at electrochemical interfaces. We illustrate next the use of the theory both for simple electron transfer processes, and for processes that involve molecular reorganization beyond the simplest harmonic approximation, with dissociative electron transfer and inclusion of all charge transfer parameters. A core example is the electrochemical reduction of the S2O82- anion. This is followed by discussion of core elements of proton and PCET processes and the electrochemical dihydrogen evolution reaction on different metal, semiconductor, and semimetal (say graphene) electrode surfaces. Other further focus is on stochastic chemical rate theory, and how this concept can rationalize highly non-traditional behaviour of charge transfer processes in mixed solvents. As a second major area we address ("long-range") chemical and electrochemical electron transfer through molecular frameworks using notions of superexchange and hopping. Single-molecule and single-entity electrochemistry are based on electrochemical scanning probe microscopies. (In operando) scanning tunnelling microscopy (STM) and atomic force microscopy (AFM) are particularly emphasized, with theoretical notions and new molecular electrochemical phenomena in the confined tunnelling gap. Single-molecule surface structure and electron transfer dynamics are illustrated by self-assembled thiol molecular monolayers and by more complex redox target molecules. This discussion also extends single-molecule electrochemistry to bioelectrochemistry of complex redox metalloproteins and metalloenzymes. Our third major area involves computational overviews of molecular and electronic structure of the electrochemical interface, with new computational challenges. These relate to solvent dynamics in bulk and confined space (say carbon nanostructures), electrocatalysis, metallic and semiconductor nanoparticles, d-band metals, carbon nanostructures, spin catalysis and "spintronics", and "hot" electrons. Further perspectives relate to metal-organic frameworks, chiral surfaces, and spintronics.

Fractional dependence of the free energy of activation on the driving force of charge transfer in the quenching of the excited states of substituted phenanthroline homoleptic ruthenium(ii) complexes in aqueous medium.

The photophysical characteristics of some homoleptic ruthenium(ii) phenanthroline derivatives are investigated in aqueous medium. The lifetimes of the excited 3MLCT state of the studied complexes were found to be very sensitive to the type of the substituents on the phenanthroline ligand and were found to increase from about 0.96 μs in case of the parent [Ru(Phen)3]2+ complex to 2.97 μs in case of [Ru(DPPhen)3]2+. The transient absorption spectra of the current set of complexes were studied also in aqueous medium. Quenching of the excited 3MLCT states of the studied complexes by molecular oxygen were studied and quenching rate constants were found to be in the range 1.02-4.83 × 109 M-1 s-1. Values of singlet oxygen quantum yields were found to be in the range 0.01 to 0.25, and the corresponding efficiencies of singlet oxygen thereby produced, f T Δ, were in the range 0.03-0.52. The mechanism by which the excited 3MLCT state is quenched by oxygen is discussed in light of the spin statistical factor rate constants and the competition between charge transfer and non-charge transfer quenching pathways. The partial charge transfer parameters, p CT, were obtained and found to be about 0.88 for all complexes except for complexes with f T Δ values lower than 0.25. The correlation of the activation free energies ΔG ≠ of the exciplexes formation with the driving force for charge transfer, ΔG CET, gives a charge transfer character of the exciplexes of about 35.0%.

Participation of fractional charge transfer on the efficiency of singlet oxygen production: Heteroleptic ruthenium (II) bipyridine derivatives

The photophysical properties of some synthesized heteroleptic polypyridyl ruthenium(II) complexes of the form [Ru(bpy)2L](PF6)2 where L = 2,2′-bipyridine, 4,4′-dimethoxy-2,2′-bipyridine, 1,10-phenanthroline, 4,4′-dimethyl-2,2′-bipyridine, 4,7-diphenyl-1,10-phenanthroline and 3,4,7,8-tetramethyl-1,10-phenanthroline, are investigated in acetonitrile. The excited state lifetime of the metal to ligand charge transfer (3MLCT) states of these complex ions are found to be ligand dependent and were found to be in the range 0.56 μs to 1.5 μs. Oxygen quenching of the excited states rate constants, kq, were found to be in the range 1.50–2.24 × 109 M−1s−1. Singlet oxygen quantum yield values, ΦΔ, are found to vary from 0.40 to 0.60 and the efficiency, fΔT, with which excited singlet oxygen, O2 (1Δg), is thereby produced was found to be in the range 0.55–0.85. Treatment of the data with charge transfer and non-charge transfer pathways using Schmidt’s model shows that partial charge transfer parameter was in the range of 0.18 to 0.58. It has also been found that fΔT decreases and oxygen quenching rate constants, kq, increases as pCT increases.

Electrochemical Corrosion Studies of Low-Alloyed Carbon Steel in Acidic Methylimidazolium Derivate Ionic Liquids with Varying Water Content

The application of ionic liquids (ILs) in a wide range of technologies requires a thorough evaluation of their corrosion behavior to typical structural steels. In this work, the corrosion effects of two acidic-type methylimidazolium derivates (potential catalyst candidates) on low-alloyed carbon steel were studied with electrochemical methods (potentiodynamic polarization and electrochemical impedance spectroscopy [EIS]). The ILs cause moderate corrosion around 0.1 mm/y at water content up to 10‰ and severe corrosion around 1 mm/y at 100‰, which underlines that before industrial applications of ILs systematic corrosion studies should be performed as part of the process design. With both ILs we found that the cathodic process exhibited apparently good linear Tafel slopes in the cathodic polarization range but in the anodic range the IL with the hydrogensulfate anion showed an active-passive transition only at the highest water concentration. In this series at lower water concentrations, under 100‰, a model assuming a potential-independent anodic current rate correctly matched with the polarization data. The EIS measurement data showed chaotic, but reproducible deviations in the low-frequency range, which were interpreted as the effect of the timely variation of distribution parameters and they apparently did not affect the charge transfer parameters essentially.

Understanding the Parameters Influencing the Impedance Response of Sulfur-Carbon Composite Cathode in Lithium-Sulfur Batteries

Lithium-sulfur (Li-S) batteries, which in recent years have been aimed at a high gravimetric energy density of 500-600 Wh kg-1, indicate particular potential in aerospace applications such as aircraft, satellites and drones.1,2 In light of this, the German Aerospace Center (DLR) has been pursuing a strategy of developing and researching metal-sulfur batteries for a decade. Herewith, we present the results of a fundamental study on the investigation of structural and compositional parameters affecting the electrochemical performance of sulfur-carbon composite cathode.Highly porous carbon materials are widely employed in composite cathodes in Li-S batteries to compensate for the non-conductive property of the sulfur element. Indeed, this would have significant effects not only on the conductivity of the cathode, but also on the diffusion and charge transfer parameters. Herewith, we have systematically studied porous carbon-based electrodes employing electrochemical impedance spectroscopy. Using a suitable transmission-line model peculiar to the porous electrodes, the resistance of bulk and pore electrolyte, inter-particles, and charge transfer is defined and quantified. The dependence of the identified processes at the open circuit voltage on the fraction of the active material, the porosity of utilized carbon and thickness of the electrode is investigated elaborately. It is indicated that the electrolyte resistance in the pore increases on increasing the content of active material, electrode thickness and on reducing the pore size distribution of the C component.Additionally, an innovative symmetrical three-electrode cell configuration with an integrated Li-ring serving as counter electrode is implemented, enabling the investigation of the cathode impedance at different depths of discharge to shed light on the kinetics of the charge transfer depending on the infiltration method. To this end, various porous carbon materials such as Ketjenblack® (mesoporous) and carbon aerogel (microporous) in combination with different sulfur infiltration techniques including gas, melt and mechanical mixing have been employed as model systems3. The thermodynamic and kinetics of charge transfer mechanisms as a function of infiltration method as well as the variation of the charge transfer resistances upon discharge/charge are discussed in details4. A. Fotouhi, D. J. Auger, L. O’Neill, T. Cleaver and S. Walus, Energies, 2017, 10, 1937.Sripad S., Viswanathan V. (2017), ACS. Energy. Lett.2, 1669-1673M. Nojabaee, B. Sievert, M. Schwan, J. Schettler, F. Warth, N. Wagner, B. Milow, K. Andreas Friedrich, J. Mater. Chem. A, 2021,9, 6508-6519.Martina Gerle, Norbert Wagner, Joachim Häcker, Maryam Nojabaee, Andreas Friedrich J. Electrochem. Soc., 2022, 169, 030505.

Theoretical SERS study of the strength and suitability of Cu12 nanostar for SERS: Complete theoretical studies, coinage metal SM12 comparisons, benzothiazole (BTH) adsorbent

Theoretical calculations were used to optimize molecular structures which help determine binding energies, and elucidate electronic properties of unsubstituted benzothiazole (BTH) adsorption on metal star models, SM12 (M = Ag/Au/Cu). BTH tends to connect via its donor nitrogen and sulfur heteroatoms as well as the π-conjugated carbon atoms; adsorption is onto the bare metal atoms of the nanostar, a single 12-membered ring, involving increasingly stable adsorption energies of −3.25/-5.71/-17.57 kcal mol−1 for BTH-Ag12/Au12/Cu12 complexes as one ascends the Group 11 triad. From the electrophilicity values, it is clear that the outermost electrons of the system will be able to travel (injected) from the chemically adsorbed BTH unit into the adsorbent SM12 within the structure of the complex. The values for changes in enthalpy and entropy for all complexes studied herein show that the motion of the atoms is constrained due to the presence of the BTH; the adsorption of BTH onto the investigated SM12 adsorbents is spontaneous. The increase of dipole moments for the complexes in aqueous media support potential for molecular recognition; drug delivery-oriented applications of the complexes are predicted to undergo dissolution in polar media such as water, offering the possibility for drug molecule recognition applications. Raman inactive modes of BTH become active within the BTH-metal complexes and experience enhancement in intensity. Adsorption behavior and thermodynamics parameters also indicate that the Cu12 cluster has the strongest interaction with maximum adsorption energy of −17.6 kcal mol−1. Density of states spectral analysis supports the charge transfer, adsorption behavior, and other thermodynamic parameters. In conclusion, density functional theory (DFT) has helped to determine electronic characteristics of SM12 clusters which have been demonstrated to be highly sensitive to the presence of BTH; these findings can allow for the molecular pairs to be used in (bio) sensor devices and to potentially trace the drug in the human body via spectrophotometry.

External electric field-dependent photoinduced charge transfer in non-fullerene organic solar cells

Based on Marcus theory, the photoinduced electron transfer properties of D-A type non-fullerene acceptor organic solar cells (OSCs) under the dependence of external electric field (Fext) were investigated. The research results shown that the charge transfer mode under different Fext intensities changes with certain regularity. Focusing on the important parameters (ΔG, λ, and VDA) that affect the charge transfer rate, it was found that both charge separation (|ΔGCS|>λ(1.3019 vs 0.8275 eV at Fext = 0) and charge recombiation (|ΔGCR|>λ, (1.9633 vs 0.8275 eV)) processes occur in the Marcus inverted region. The ΔGCS is relatively sensitive to Fext, and the calculated ΔGCS at different Fext intensities yields an increment of 0.0073 eV, which is also the main reason for the increase in the rate of charge separation. The ΔGCR ranges between −1.9633 and −1.9637 eV, is insensitive to Fext, and ΔGCR is significantly smaller than ΔGCS, which makes the charge recombination rate significantly smaller than the charge separation rate. For VDA, it is found that VDA will transition to a new level only when the Fext intensity reaches a certain intensity, which also enables to obtain a faster charge separation rate. By studying the charge transfer parameters in different polar solvents, it is found that polar solvents can indeed increase the charge transfer rate. To a certain extent, our results also demonstrate that the addition of Fext can further improve the performance of non-fullerene acceptor OSCs.

A Theoretical Investigation of Charge Transfer Dynamics from Sensitized Molecule D35CPDT Dye to SnO_2 and TiO_2 Semiconductor

In this research, the dynamics process of charge transfer from the sensitized D35CPDT dye to tin(iv) oxide( ) or titanium dioxide ( ) semiconductors are carried out by using a quantum model for charge transfer. Different chemical solvents Pyridine, 2-Methoxyethanol. Ethanol, Acetonitrile, and Methanol have been used with both systems as polar media surrounded the systems. The rate for charge transfer from photo-excitation D35CPDTdye and injection into the conduction band of or semiconductors vary from a to for system and from a to for the system, depending on the charge transfer parameters strength coupling, free energy, potential of donor and acceptor in the system. The charge transfer rate in D35CPDT / the system is larger than the rate in D35CPDT/ a system depending on transition energy and driving energy. However, the charge transfer for both systems to be large is associated with large transition energy, decreasing driving energy and potential, and increasing strength coupling with Methanol solvent.