Charge Transfer Mechanism Research Articles

Visible light induced S-scheme charge transfer mechanism from Bi12TiO20 to CsPbBr3 for photodegradation of organic pollutants in aqueous solution

This work describes the formation of CsPbBr3/Bi12TiO20 S-scheme heterojunction photocatalysts using 3-mercaptopropionic acid (MPA) passivated CsPbBr3 nanocrystals (CPB) combined with Bi12TiO20 (BTO) nanorods. Under illumination, the charge carriers—undergo a process known as the S-scheme charge transfer, which significantly enhances their redox capability. The most efficient photodegradation of Rhodamine B (RhB) was recorded with the fine-tuned 10%CPB/BTO composite (degradation rate of 95.35% within 50 min, kapp = 0.06202 min−1). This improvement is primarily due to the MPA passivation, which increases the stability of the catalyst in aqueous solutions, and the S-scheme heterojunction design, which improves carrier separation and utilisation efficiency.

Theoretical Insights into the Effect of Different Numbers of Thiophene Groups on Hydrogen Bond Interaction and Excited-State Intramolecular Proton-Transfer Process for Flavonoid Derivatives.

In this study, we systematically explored the impact of varying the number of thiophene groups on the hydrogen bond interaction and excited-state intramolecular proton-transfer (ESIPT) processes in flavonoid derivatives (STF, DTF, and TTF) using the density functional theory and time-dependent density functional theory methods. Initially, a thorough analysis of the optimized geometric structures revealed that the intramolecular hydrogen bond in the S1 state is enhanced and gradually weakened as the number of thiophene groups increases. To gain a deeper understanding of the hydrogen bond interaction, topological analysis, interaction region indicator scatter plots, and isosurface plots were employed. These images provide further insights that align with the structural analysis. Additionally, we observed a red-shift in the electronic spectra (absorption and fluorescence spectra), which is primarily attributed to the narrowing of the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital, as elucidated by the frontier molecular orbitals. Furthermore, a combined analysis between the hole-electron distribution and the transition density matrix heat map shows that electron excitation involves the unidirectional charge-transfer mechanism. In the end, by conducting relaxed potential energy curve scans, we found that an increase in the number of thiophene groups elevates the energy barrier for ESIPT, making it more challenging for the reaction. In summary, our study underscores the vital effect of thiophene-substituted numbers in modulating the ESIPT process, which is able to provide valuable insights for the design and synthesis of desired organic fluorescent probes in the future.

S-scheme BiOBr/Bi2WO6 with oxygen vacancies for synergistic photodegradation and hydrogen generation: Mechanisms insight and DFT calculations

An S-type heterojunction photocatalyst Bi2WO6/BiOBr (BWO/BiOBr) with an interlaced band structure and abundant oxygen vacancies (Ov) was synthesized using a hydrothermal method and high-temperature calcination. The surface was modified with carbon quantum dots (CQDs) to create a 0D/2D/2D structure. The resulting photocatalyst exhibited superior performance, with a degradation rate for Norfloxacin (NOR) antibiotics surpassing Bi2WO6 with oxygen vacancies (BWO-Ov) and BiOBr by 6.55 and 3.96 times, respectively. Notably, it achieved a high hydrogen generation rate of 459.49 μmol·g−1·h−1 under visible light. The enhanced carrier transfer and solar absorption were attributed to the synergistic effect of CQDs and S-type heterojunctions. The face-to-face 2D/2D structure provided abundant reaction sites. The influence of initial NOR concentration and photocatalyst dosage on photocatalytic activity was investigated in our study. Incorporating CQDs improved solar absorption, as confirmed by NOR degradation under various wavelengths. Electron spin resonance (ESR) analysis indicated the generation of reactive oxygen species. Density functional theory (DFT) calculations and characterization explored charge transfer mechanisms and degradation pathways. These findings contribute to the design of efficient S-type heterogeneous photocatalysts for sustainable energy and environmental applications.

Insights into pseudocapacitive mechanism of aqueous ammonium-ion supercapacitors with exceptional energy density and cyclability

Aqueous ammonium-ion (NH4+) supercapacitors (AASCs) have recently garnered increased concerns but are consistently facing the challenge of lower energy density. Herein, a high-performance electrode (CuCo2S4@CP) with pseudocapacitive property has been synthesized and primordially applied to AASCs. The CuCo2S4@CP electrode has an ultrahigh specific capacity of 1512 C g−1 at 1 A g−1 and a distinguished cyclic stability of 87.74 % after 10,000 cycles. When the CuCo2S4@CP electrode is combined with the activated carbon (AC) negative electrode, the CuCo2S4@CP//AC device exhibits a high specific capacity of 547 C g−1 at 1 A g−1, excellent cycle stability (83.28 % at 10 A g−1), high energy density of 74.17 Wh kg−1, and excellent device consistency. In addition, the charge transfer mechanism of CuCo2S4@CP electrode in NH4+electrolyte has been elucidated. The CuCo2S4 surface density functional theory (DFT) elucidates that NH4+ has a minimal contribution to the surface, implying an insertion behavior of NH4+ within the CuCo2S4 lattice. Subsequent ex-situ characterization further confirms the energy storage process, revealing charge transfer to Co atoms following NH4+ insertion into CuCo2S4. The analysis of charge distribution illustrates an energy storage mechanism wherein the hydrogen bond formed between NH4+ and CuCo2S4 serves as the transport channel for charge transfer, facilitating the process of electrons from NH4+ to Co atoms. Therefore, the pseudocapacitive mechanism of CuCo2S4 with NH4+ provides a blueprint for sustainable energy storage with high energy density in aqueous electrolyte.

Photovoltaic induced self-powered gas sensor based on 2D MoS2 incorporated NbSe2 nanorods heterostructure for NH3 gas sensing at room temperature

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted significant attention for their optical and gas-sensing applications due to their exceptional sensitivity. Reliable selectivity and low power consumption are two major requirements for photodetector and gas sensor applications in next-generation electronic devices and the Internet of Things. Self-powered sensors (especially photovoltaic gas sensors) can solve these problems. In this study, for the first time, we report 2D TMDs (NbSe2-MoS2 hybrid) on a SiO2/Si substrate to fabricate photovoltaic self-powered gas sensors. The gas sensors are operated by the photovoltaic effect of the NbSe2-MoS2 nanostructure, which is prepared using the liquid phase exfoliation process. Initially, it was revealed that the present hybrid material exhibits photovoltaic properties under light illumination, with a circuit current of 0.25 µA and a circuit voltage of 34 mV. The NbSe2-MoS2 nanostructure characteristics were then used for NH3 gas sensing at different concentrations, and the gas sensing response was detected from low (8.8 % at 10 ppm) to high (28.8 % at 500 ppm) concentrations. The built-in electric field occurred between the NbSe2-MoS2 junction and eventually operated as a driving force for NbSe2-MoS2 gas sensing without an external bias voltage. The physisorption of gas molecules on their surface prompts a charge-transfer mechanism that improves the gas sensor response. The combined outcome of NbSe2-MoS2 heterostructures could pave way to next-generation gas sensing device fabrications.

Unravelling the La dopant induced physicochemical changes and the electrical behaviour on BaFeO3 under oxidising and reducing atmospheres

Electroceramic oxides like La-doped BaFeO3 garner greater interest owing to their tunability of mixed ionic conduction. However, reports on the effect of La on the microstructural changes, the type of conduction mechanism under different atmospheres and the negative charge transfer influenced by the Fe-O hybridization in Ba1−xLaxFeO3−δ are hardly available. Doping La induces cation vacancies and Fe reduction, creating nanorod decorated surface after the high-temperature treatment. Conductivity studies expose the rate-limiting steps for hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) as the ohmic resistances and Ba segregation effects. Among the samples studied, Ba0.9La0.1FeO3−δ performs better at 800 °C with an activation energy of ∼0.35 eV under both oxidizing and reducing atmospheres. Surface analysis after EIS reveals Fe and O with different oxidation states that enhance the total conductivity. The amount of hydroxyl species retained (23.66% for Ba0.9La0.1FeO3−δ ) and the ratio of the adsorbed to the lattice oxygen (15.33% for Ba0.9La0.1FeO3−δ ) gives insight on HOR and ORR activities. Also, computational studies validated the negative charge transfer mechanism of the samples under thermally assisted oxidation. The results indicate Ba0.9La0.1FeO3−δ as a tuneable electrode for solid oxide cells.

A novel type-II–II heterojunction for photocatalytic degradation of LEV based on the built-in electric field: carrier transfer mechanism and DFT calculation

Heterojunctions play a crucial role in improving the absorption of visible light and performance of photocatalysts for organic contaminants degradation in water. In this work, a novel type-II–II Ag2CO3/Bi2WO6 (AB) heterojunction was synthesized by hydrothermal reaction and in situ-precipitation methods. The mechanisms of charge transfer and carrier separation at the interface of heterojunctions and the influence on the photocatalytic activity were investigated. The degradation of levofloxacin (LEV) under visible light irradiation was employed to evaluate the photocatalytic performance of AB. The results showed that 85.4% LEV was degraded by AB, which was 1.38 and 1.39 times higher than that of Bi2WO6 and Ag2CO3, respectively. The work functions of the different crystal planes in the AB heterojunction, which was calculated by density functional theory, are a significant difference. The Fermi energy (Ef) of Ag2CO3 (− 6.005 eV) is lower than Bi2WO6 (− 3.659 eV), but the conduction band (CB) is higher. Therefore, using AB heterojunctions as an example, the research explored the mechanism of type-II–II which CB and Ef of one semiconductor cannot simultaneously surpass those of another material, based on the built-in electric field theory. Through this analysis, a deeper understanding of type-II heterojunctions was achieved, and providing valuable insights into the behavior of this specific heterojunction system.

Bi-ZFO/BMO-Vo Z-scheme heterojunction photocatalysis-PMS bidirectionally enhanced coupling system for environmental remediation

Given the urgency of organic pollutant removal and the low efficiency of advanced oxidation processes (AOPs), a novel Bi-ZFO/BMO-Vo photocatalyst was fabricated via the solvothermal method. A coupling system was constructed to combine photocatalysis with peroxymonosulfate (PMS) oxidation processes, which synergistically degrade organic pollutants. Bi-ZFO/BMO-Vo exhibited excellent photocatalytic performance, which could remove 100 % RhB in 110 min and degrade 100 % MG in 70 min, and 88 % H-TC in 50 min. The excellent catalytic performance of Bi-ZFO/BMO-Vo was not only attributed to the synergistic effect of PMS activation and photocatalysis, but also attributed to the SPR effect of Bi nanoparticles, electron capture of oxygen vacancies, and intense contact of Bi-ZFO/BMO-Vo heterojunctions. The active species capture experiments and EPR tests indicated that 1O2, SO4–·, ·OH, and O2–· worked together for the RhB removal. The degradation intermediates of RhB were identified by LC-MS. Based on the experimental results, the band structure and Z-scheme charge transfer mechanism were proposed. Toxicity evaluation indicated that Bi-ZFO/BMO-Vo-Vis/PMS could significantly reduce RhB toxicity. This efficient and stable catalyst is expected to be used in organic wastewater degradation and practical applications.

Cu-BTC-derived Cu@C as nano-heater embedded in 3D g-C3N4 for photothermal-coupled photocatalytic CO2 reduction under full-spectrum solar irradiation

This study developed a novel Cu@C/NCN-T composite for efficient photothermal catalytic CO2 reduction. The composite, consisting of carbon-coated Cu (Cu@C) derived from Cu-BTC embedded in three-dimensional graphitic carbon nitride (NCN-T), was immobilized on the surface of carbonized wood (C-wood) floating on water, creating a triphase system (CO2, H2O, and catalyst). The optimized composite demonstrated remarkable CO2 photothermal reduction performance, achieving a rate of 31.3 μmol·g−1·h−1. This performance surpassed that of pure NCN-T and Cu@C by 1.6 and 3.8 times, respectively. The combination of Cu and carbon materials endowed Cu@C/NCN-T with excellent light-absorption properties, resulting in a photothermal effect that elevated the surface temperature and facilitated the catalytic reaction. Furthermore, the Schottky junction formed between Cu@C and NCN-T promoted the separation of electron-hole pairs, with Cu@C acting as charge channels. A charge transfer mechanism was proposed to explain these findings. This catalyst engineering approach holds promise for the development of efficient non-noble metal catalysts for rapid CO2 photothermal reduction.

Interfacial-electric-field guiding design of a Type-I FeIn2S4@ZnIn2S4 heterojunction with ohmic-like charge transfer mechanism for highly efficient solar H2 evolution

Manipulating charge transfer pathways in Type-I heterojunctions is essential to address the mismatched energy bands and the often-neglected internal electric field (IEF). This study reports the successful engineering of a Type-I FeIn2S4@ZnIn2S4 heterojunction exhibiting an ohmic-like charge transfer mechanism, driven by the IEF arising from considerable Fermi level differences. The ohmic-like Type-I junction facilitates efficient electron transfer from ZnIn2S4 to FeIn2S4 and preserves the oxidizing holes in ZnIn2S4 for effective scavenger oxidation. This unique feature prevents the inefficient charge separation commonly observed in conventional Type-I heterojunctions. Due to the advantageous ohmic-like electron transfer, an optimized composition of FeIn2S4@ZnIn2S4 with a weight percentage of 10 % FeIn2S4 achieves a notable hydrogen evolution rate of 4.21 mmol g-1h−1, six times higher than isolated ZnIn2S4. Furthermore, the validation of the ohmic-like charge transfer mechanism is supported by theoretical analyses and advanced characterization techniques, including in-situ X-ray photoelectron spectroscopy (XPS), Kelvin probe force microscopy (KPFM), and surface photovoltage (SPV) measurements. This present study introduces a pioneering prototype that shows the successful incorporation of the desired charge transfer pathway in a Type-I heterojunction through the implementation of an IEF regulation strategy.

Single atom catalysts with anion center toward oxygen electrocatalysis based on the conductive 1T-HfTe2

Advancing efficient catalysts for oxygen reduction reaction (ORR) or oxygen evolution reaction (OER) is imperative for commercializing emerging energy devices. Using density functional theory (DFT) calculations, we propose doping different transition metal (TM) atoms to regulate the electronic structures of the two-dimensional 1T-HfTe2 monolayer to achieve bifunctional catalysis for the ORR/OER. Due to the small electronegativity of the Hf atom, we found the doped TM atoms can generally form anion centers by accepting abundant charges from the Hf interlayer. At the same time, the highly conductive 1T-HfTe2 contributes to the charge transfer between the active center and the reaction intermediates, rendering the designed SACs the tunable activity for the reactions. By comparing the theoretical overpotentials of ORR and OER on 15 single-atom catalysts (SACs), Pt-doped system exhibits excellent catalytic activity for both ORR and OER, outperforming the traditional Pt(111) and RuO2(110) catalysts. Based on the charge transfer mechanism, we clarified that the doped TM atoms act as a ‘bridge’ to transfer the electrons from the substrate to the reaction intermediates, thereby effectively contributing to the improvement of catalytic activity. In summary, our study shows that, by doping appropriate TM atoms, the intrinsic inert HfTe2 can be activated toward efficient ORR/OER. This could provide some guidance for the design of new two-dimensional ORR/OER bifunctional catalyst materials.

Novel Graphitic Carbon Nitride/Co-B-P Nanocomposites with Significantly Enhance Visible-Light Photocatalytic Hydrogen Production from Water Splitting

As a promising metal-free photocatalyst for hydrogen (H2) production through water splitting under visible-light irradiation, graphitic carbon nitride (g-C3N4) photocatalysts decorated with CoBP was prepared via simple ultra sonification. This paper highlights the structures of the photocatalysts, their stability, rate of hydrogen evolution and the mechanism of charge transfer within the photocatalysts. The prepared C3N4/CoBP nanocomposite photocatalysts were characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy and UV–visible (UV–vis) diffuse reflectance spectroscopy. After detailed analysis, the C3N4/CoBP nanocomposite photocatalysts showed excellent photocatalytic performance, which was due to the formation of the heterostructured hybrids of g-C3N4 and CoBP. The effects of C3N4/CoBP nanohybrids on H2 evolution were evaluated. The effects improved with increasing load of CoBP until the optimal level (5 wt% CoBP with visible-light irradiation at λ ≥420 nm). The maximum and remarkable photocatalytic H2 evolution rate of 51.68 μmol h−1 was achieved, which was 3.8 times that obtained from pure g-C3N4. Moreover, the C3N4/CoBP heterostructured nanohybrids demonstrated extremely high photostability and recyclability for H2 evolution after visible light illumination. The composite hybrid accelerated the separation and transfer of photogenerated charge carriers and subsequently suppressed charge recombination. Conclusively, this study offered an opportunity for the design and synthesis of highly stable and efficient C3N4/CoBP nanocomposite photocatalysts for energy conversion and utilisation.

Critical role of dopant bond strength in enhancing the conductivity of n-type doped κ-Ga2O3

We report a density functional theory study on the effects of n-type doping on the electrical conductivity of κ-Ga2O3. Both group-IV (X = Si, Ge, Sn) and group-VII dopants (Y = F, Cl, Br, I) are considered. All dopants introduce resonant donor states above the conduction band minimum, which induce a semiconductor-to-metal transformation. The resonant donor states interact with the extended conduction band-edge via a charge transfer mechanism, altering the band-edge effective mass me* and electron mobility μe. me* exhibits a linear dependence on the strength of X-O (Ga-Y) bonds, making the latter a good descriptor for quantifying the effect of dopants. Using this descriptor, we predict that dopant C may provide a higher conductivity under O-rich condition.

Linear Vibronic Coupling Approach for Surface-Enhanced Raman Scattering: Quantifying the Charge-Transfer Enhancement Mechanism.

The outstanding amplification observed in surface-enhanced Raman scattering (SERS) is due to several enhancement mechanisms, and standing out among them are the plasmonic (PL) and charge-transfer (CT) mechanisms. The theoretical estimation of the enhancement factors of the CT mechanism is challenging because the excited-state coupling between bright plasmons and dark CT states must be properly introduced into the model to obtain reliable intensities. In this work, we aim at simulating electrochemical SERS spectra, considering models of pyridine on silver clusters subjected to an external electric field E⃗ that represents the effect of an electrode potential Vel. The method adopts quantum dynamical propagations of nuclear wavepackets on the coupled PL and CT states described with linear vibronic coupling models parametrized for each E⃗ through a fragment-based maximum-overlap diabatization. By presenting results at different values of E⃗, we show that indeed there is a relation between the population transferred to the CT states and the total scattered intensity. The tuning and detuning processes of the CT states with the bright PLs as a function of the electric field are in good agreement with those observed in experiments. Finally, our estimations for the CT enhancement factors predict values in the order of 105 to 106, meaning that when the CT and PL states are both in resonance with the excitation wavelength, the CT and PL enhancements are comparable, and vibrational bands whose intensity is amplified by different mechanisms can be observed together, in agreement with what was measured by typical experiments on silver electrodes.

Ni-based plasmonic photocatalysts for solar to energy conversion: A review

Plasmonic-based semiconductors are compelling contenders of current research endeavors to drive chemical reactions via plasmonic and phononic light-matter interactions. Among various plasmonic metals, Ni as a non-precious metal has been extensively studied due to its ability to participate in interband excitation and comparable metal-hydrogen binding energy to that of noble metals including Pt and Ag. The phenomenally high charge-carrier density in photoexcited Ni-based plasmonic nanomaterials offers photochemical conversion of high-energy chemical bonds accompanied by thermal effect. Since the research on the plasmonic activity of the non-precious metal is still emerging, no comprehensive review has addressed the significance of Ni as a plasmonic photocatalyst to the best of our knowledge. This review article sums up the recent progress in the field of plasmonic photocatalysis focusing on Ni-based photocatalysts. The basic principles of the plasmonic effect have been presented, along with an explanation of why Ni may be a viable option. Ni has been investigated for use as a co-catalyst and plasmonic photocatalyst in composite photocatalysis to achieve an accelerated process. After the energy transfer mechanism has been assessed, the review covers the state-of-the-art of two significant effects—plasmon energy transfer and the localized heating effect that are responsible for increased efficiency in energy production. In conclusion, we have included a synopsis of the assessment and emphasized the problems that must be resolved before the technology can be made available for purchase. In a nutshell, the chemistry of plasmonic photocatalysis is promising; but acquiring a detailed mechanism of charge transfer and utilization of charge carriers is still a roadblock in apprehending the full potential of plasmonic photocatalysis. Therefore, this study aims to motivate the scientific community to envision impactful work in the creation of next-generation plasmonic photocatalysts.

Ultrathin layer TAFC on BiVO4 with ligand-to-metal charge transfer enhances built-in electric field for boosting photoelectrochemical water oxidation

To reveal the mechanism of charge transfer between interfaces of BiVO4-based heterogeneous materials in photoelectrochemical water splitting system, the cocatalyst was grown in situ using tannic acid (TA) as a ligand and Fe and Co ions as metal centers (TAFC), and then uniformly and ultra-thinly coated on BiVO4 to form photoanodes. The results show that the BiVO4/TAFC achieves a superior photocurrent density (4.97 mA cm−2 at 1.23 VRHE). The charge separation and charge injection efficiencies were also significantly higher, 82.0 % and 78.9 %, respectively. From XPS, UPS, KPFM, and density functional theory calculations, Ligand-to-metal charge transfer (LMCT) acts as an electron transport highway in TAFC ultrathin layer to promote the concentration of electrons towards metal center, leading to an increase in the work function, which enhances the built-in electric field and further improves the charge transport. This study demonstrated that the LMCT pathway on TA-metal complexes enhances the built-in electric field in BiVO4/TAFC to promote charge transport and thus enhance water oxidation, providing a new understanding of the performance improvement mechanism for the surface-modified composite photoanodes.

Efficient photocatalytic CO2 reduction achieved by constructing Bi4O5Br2/Bi-MOF Z-scheme heterojunction

Building efficient catalysts is an urgent issue in the field of photocatalytic CO2 reduction, and Z-scheme heterojunction structures can availably suppress the recombination of photo generated carriers and improve photocatalytic performance. This study successfully prepared a new type of Bi4O5Br2/Bi-MOF composite photocatalyst through self-assembly method. After 5 h of simulated sunlight exposure, the optimized sample 50-Bi4O5Br2/Bi-MOF photocatalytic reduction of CO2 to CO efficiency (23.78 μmol·g−1·h−1) was 5.09 times higher than pure Bi4O5Br2, and the CH4 yield (5.39 μmol·g−1·h−1) was 2.52 times that of pure Bi-MOF. In addition, in the cyclic experiment, the catalyst had high stability and reusability. The Z-scheme charge transfer mechanism was confirmed through band structure analysis, Electron spin resonance (ESR), Ultraviolet photoelectron spectroscopy (UPS) and other related characterizations. This work provided an important strategy for designing efficient Z-scheme heterojunction photocatalysts.

BaTi0.85Zr0.15O3/MOF-5 nanocomposite: Synthesis, characterization and photocatalytic activity toward tetracycline

It has been proposed that oriented anchoring strategies can be used to organize BaTi0.85Zr0.15O3 (BTZ) quantum dots (QD) with MOF-5 to provide highly efficient catalytic degradation of tetracycline (TC). This study presents the preparation of [Zn4O (BDC)3] (BDC = benzene-1,4dicarboxylate) metal–organic framework-5 (MOF-5)/BTZ nanocomposites by a facile one-pot solvent-thermal precipitation method. The as-synthesized samples were identified by XRD, TG-DTG, UV–VIS DRS, FESEM, FTIR, BET, TEM, PL, and EDX characterization techniques. The photocatalytic ability of nanocomposite BTZ (30 %wt)/MOF-5 was particularly impressive among the binary photocatalysts. In a 10 ppm solution of TC, BTZ (30 wt%)/MOF-5 demonstrated superior photodegradation activity, with 95 % degradation efficiency of TC determined by HPLC. The best response was achieved at pH 11 with catalyst dosages of 0.2 g/L, irradiation time of 150 min, and CTC of 10 ppm. An internal electric field was suggested to mediate the direct Z-scheme charge transfer mechanism between BTZ and MOF-5. The improvement was achieved by fabricating BTZ and MOF-5 in an indirect Z-scheme heterojunction system. Photogenerated electron-hole separation can be accelerated by BTZ/MOF-5 with improved redox capabilities. Overall, taking advantage of an enhanced redox capacity under ultraviolet (UV) light irradiation, this study demonstrates how to promote efficient antibiotic degradation using MOF-based nanocomposites. Moreover, photodegradation kinetics were studied using the Hinshelwood formula, giving 0.0113 min−1 (slope) and 61.32 min as t1/2. In the COD experiment, mineralized TC molecules had y = -0.0144 + 0.0444x, r2 = 0.9942, and k = 0.0144 min−1 (t1/2 = 48.12 min).

Coupling Process between Droplet and Iron Investigated by Reactive Molecular Dynamics Simulations.

The droplet-to-iron electrochemical reaction is common in nature and industrial production, and it causes damage to the economy, safety, and the environment. The electrochemical reaction of droplet-to-iron is a coupling process of wetting and corrosion. Presently, investigations into electrochemical reactions mainly focus on the corrosions caused by a solution, and wetting is rarely considered. However, for the droplet-to-iron electrochemical reaction, the mechanism of charge transfer in the process is still unclear. In this paper, a reactive molecular dynamics simulation model for the droplet-to-iron electrochemical reaction is developed for the first time. The electrochemical reaction of droplet-to-iron is studied, and the interaction between droplet wetting and corrosion on iron is investigated. The effects of temperature, electric field strength, and salt concentration on the electrochemical reaction are explored. Results show that droplet wetting on the iron surface and the formation of a single-molecular-layer ordered structure are prerequisites for corrosion. The hydroxyl radicals that penetrate the ordered structure acquire electrons from iron atoms on the substrate surface under the action of Coulomb forces and form iron-containing oxides with these iron atoms. The corrosion products and craters lead to a reduced droplet height, which promotes droplet wetting on iron and further intensifies the droplet-to-iron electrochemical reaction.

Selective Formation of Homochiral Dimers by Intermolecular Charge Transfer on a hBN Nanomesh.

In this study, a comprehensive characterization was conducted on a chiral starburst molecule (C57H48N4, SBM) using scanning tunneling microscopy. When adsorbed onto the hBN/Rh(111) nanomesh, these molecules demonstrate homochiral recognition, leading to a selective formation of homochiral dimers. Further tip manipulation experiments reveal that the chiral dimers are stable and primarily controlled by strong intermolecular interactions. Density functional theory (DFT) calculations supported that the chiral recognition of SBM molecules is governed by the intermolecular charge transfer mechanism, different from the common steric hindrance effect. This study emphasizes the importance of intermolecular charge transfer interactions, offering valuable insights into the chiral recognition of a simple bimolecular system. These findings hold significance for the future advancement in chirality-based electronic sensors and pharmaceuticals, where the chirality of molecules can impact their properties.