Enhanced Charge Transfer Research Articles

Fano Resonance in CO2 Reduction Catalyst Functionalized Quantum Dots.

Molecular catalyst functionalized semiconductor quantum dots (QDs) are a promising modular platform for developing novel hybrid photocatalysts. The interaction between adsorbed catalyst vibrations and the QD electron intraband absorption can influence the photophysical properties of both the QD and the catalysts and potentially their photocatalysis. In CdSe QDs functionalized by the CO2 reduction catalyst, Re(CO)3(4,4'-bipyridine-COOH)Cl, we observe that the transient Fano resonance signal resulting from coupling of the catalyst CO stretching mode and the QD conduction band electron mid-IR intraband absorption appears on an ultrafast time scale and decays with the electron population, irrespective of the occurrence of photoreduced catalysts. The Fano asymmetry factor increases with an increase in the adsorbed catalyst number and a decrease in QD sizes. The latter can be attributed to an enhanced charge transfer interaction between the more strongly quantum-confined QD conduction band and catalyst LUMO levels. These results provide a more in-depth understanding of interactions in excited QD-catalyst hybrid photocatalysts.

Double-Chain Copolymer Network via In Situ Polymerization Enables High-Stability and Lead-Safe Perovskite Solar Cells.

Lead halide perovskite solar cells (PSCs) have made significant progress due to their low cost and high efficiency. However, the long-term stability and lead toxicity of PSCs remain a huge challenge for further commercialization. Herein, we designed a multifunctional additive PAE with photosensitive properties to overcome these difficulties. A unique double-chain copolymer network can be constructed via in situ polymerization induced by ultraviolet (UV) light. The multiple active sites in the polymer chains can passivate various defects and enhance charge transfer. Meanwhile, the vast network provides an effective defense for perovskite to stabilize the internal structure and resist harsh external environments, thus delaying the degradation of devices and maximizing the suppression of toxic lead leakage. Remarkably, the devices protected by the network achieved a champion power conversion efficiency (PCE) of 26.20% (certified as 25.69%), the unencapsulated devices suppressed 80% of lead leakage and the encapsulated devices maintained 93% of the initial PCE after 1000 h in a humid and thermal environment (65 °C and 85% RH).

Synergistic Halogen-Bonding Passivation and Carboxylic Acid Anchoring in Carbazole-Based Hole-Transport Materials Enhance Performance and Stability of p-i-n Perovskite Solar Cells.

Interfaces pose significant challenges to the performance and stability of perovskite solar cells (PSCs), as defects and weak interactions at these boundaries can lead to energy losses and degradation. To address these issues, it is crucial to functionalize hole transport materials (HTMs) to effectively manage interfacial defects and enhance charge transfer. This study introduces a carbazole-based hole transport layer (TC-ICA) that leverages halogen bonding (XB) for enhanced interface passivation with the perovskite layer and carboxylic group anchoring to the indium-doped tin oxide (ITO). By combining these functionalities, the TC-ICA material leads to exceptional device stability (99% shelf stability over 320 days of air storage and a T80-lifetime exceeding 1000 h under light soaking) and enhanced efficiency (15.4%), outperforming single-function materials like TC-CA (14.7%) and TC-I (10.7%). This dual-function strategy marks a significant advancement in the quest for high-performance and long-term stable PSCs.

Charge-transfer dynamics in S-scheme photocatalyst.

Natural photosynthesis represents the pinnacle that green chemistry aims to achieve. Photocatalysis, inspired by natural photosynthesis and dating back to 1911, has been revitalized, offering promising solutions to critical energy and environmental challenges facing society today. As such, it represents an important research avenue in contemporary chemical science. However, single photocatalytic materials often suffer from the rapid recombination of photogenerated electrons and holes, resulting in poor performance. S-scheme heterojunctions have emerged as a general method to enhance charge transfer and separation, thereby greatly improving photocatalytic efficiencies. This Perspective delves into the electron transfer dynamics in S-scheme heterojunctions, providing a comprehensive overview of their development and key characterization techniques, such as femtosecond transient absorption spectroscopy, in situ irradiated X-ray photoelectron spectroscopy and Kelvin probe force microscopy. By addressing a critical research gap, this work aims to trigger further understanding and advances in photo-induced charge-transfer processes, thereby contributing to green chemistry and the United Nations sustainable development goals.

Engineering Mn-doped Co-based heterostructures with oxygen vacancies toward efficient industrial-scale water oxidation catalysis.

Engineering Mn-doped Co-based heterostructures with oxygen vacancies toward efficient industrial-scale water oxidation catalysis.

Carbon Quantum Dot Functionalized Nanofiber‐Based Triboelectric Nanogenerator With Boosted Output and Fluorescence Function

ABSTRACTAdvanced nanofibrous materials with excellent performance and functional integration is highly desired for developing emerging wearable electronics. In this work, carbon quantum dots/poly(vinylidene fluoride) (CDs/PVDF) based composite nanofibrous material is proposed and acts as a highly negative material to boost output performance for triboelectric nanogenerators (TENGs). The nanometer‐sized and surface‐functionalized CDs acting as nucleating inducers facilitate the polarized β‐phase transition of PVDF polymer. The more negative surface charge density of CDs/PVDF nanofibrous membrane is generated through the polarized β‐phase PVDF, thereby leading to a larger electrostatic potential difference to enhance charge transfer. Besides the decreased beaded defects, more uniform morphology fibers are yielded to improve the effective contact surface area. Moreover, the CDs/PVDF composite nanofibers demonstrate the unique multicolor fluorescence effect enabling promising applications in visualized displays and sensing. Finally, the fabricated TENG features a short‐circuit current density of ~61.8 mA/m2 and a maximum peak power density of ~11.7 W/m2, exceeding that of most state‐of‐the‐art nanofiber‐based TENG reported to date. As a demonstration of application potential, this TENG shows the energy‐harvesting ability to charge capacitors and light up 125 green LEDs and self‐powered sensing capability for human motion monitoring. This work provides insights for exploiting novel tribomaterials for high‐output TENGs with promising potential in biomechanical energy harvesting, self‐powered sensing, and so forth.

Precision-Grown Bi2O2Se Flakes for Exceptional Electrocatalytic Performance in Acidic Medium.

Efficient hydrogen production via electrochemical water splitting is vital for sustainable energy applications, with the HER in acidic media requiring highly effective catalysts. In this study, we report the synthesis of Bi2O2Se nanosheets through a scalable hydrothermal method, achieving exceptional catalytic performance in acidic conditions. The Bi2O2Se nanosheets exhibit a low overpotential of 104 mV at 10 mA cm-2, significantly outperforming other bismuth-based HER catalysts. The superior activity is attributed to the unique structural and electronic properties of Bi2O2Se, which provide abundant active sites and enhance charge transfer efficiency. Electrochemical studies, including Tafel slope analysis and impedance spectroscopy, confirm rapid HER kinetics and reduced charge-transfer resistance. Additionally, the catalysts demonstrate excellent long-term stability under acidic conditions, maintaining their performance during extended electrolysis. This work highlights the potential of Bi2O2Se as a highly efficient and cost-effective catalyst tailored for acidic HER applications. The dual-electrode system comprising Bi2O2Se@CP as the cathode and RuO2@CP as the anode demonstrated outstanding performance in overall water splitting. This system required a battery voltage of only 1.49 V to achieve a current density of 10 mA cm-2, highlighting the superior electrocatalytic efficiency of Bi2O2Se in conjunction with RuO2. By offering valuable insights into the design and optimization of bismuth-based materials, these findings pave the way for advancing sustainable hydrogen production technologies through scalable and efficient catalytic solutions.

INFLUENCE OF TERMINAL ELECTRON ACCEPTORS ON ANTHRACENE‐BASED D‐π‐A SYSTEMS FOR ENHANCED RESISTIVE WORM MEMORY PERFORMANCE

This study explores the application of small molecule‐based anthracene systems in resistive memory devices. We have designed and synthesized a series of five anthracene functionalized Donor‐π‐Acceptor (D‐π‐A) compounds for non‐volatile memory device applications employing various acceptor units such as fluorophenyl, trifluoromethylphenyl, formylphenyl, nitrophenyl and pyridinyl units. The photophysical studies revealed efficient intramolecular charge transfer within the compounds, and the electrochemical analysis confirmed a favorable band gap in the range of 2.65‐2.79 eV. The thin‐film morphologies displayed excellent surface coverage and self‐assembly, facilitating enhanced charge transfer. Moreover, the single‐crystal analyses further confirmed their crystalline nature and the presence of efficient charge carrier pathways. All the synthesized compounds exhibited a binary write‐once read‐many times (WORM) memory behaviour. Among them, the compound with a nitrophenyl substituent achieved the highest ON/OFF current ratio of 104, while the compound containing a fluorophenyl substituent exhibited the lowest threshold voltage of 1.87 V. Furthermore, the computational studies helped to substantiate a charge transfer and charge trapping mechanism in the fabricated devices. These findings highlight the potential of the synthesized compounds as promising candidates for high‐density data storage applications.

Nickel silicide nanowire anodes for microbial fuel cells to advance power production and charge transfer efficiency in 3D configurations

The growing energy demands of the industrial world have driven advancements in green energy technologies. Microbial fuel cells (MFCs), which harness power from microorganisms, show promise for energy extraction from wastewater and sludge. However, challenges remain in improving power output and sustaining performance under high-charge conditions. Incorporating nanomaterials into 3D structures offers potential solutions, including miniaturized designs. This study introduces nickel silicide nanowires as anode materials for MFCs. Synthesized on nickel foam, these nanowires form a 3D nickel-based structure with semi-metal nanostructures. Tested in a microfluidic MFC system with E. coli, this configuration achieved significant improvements, including a peak power density of 323 mW m-2 and a current density of 2.24 A m-2, representing a 2.5-fold increase in power and a 4-fold boost in current compared to bare nickel foam. Nutrient broth proved the most effective charge transfer medium, surpassing glucose and urea by 3 and 5 times, respectively. These results, supported by EIS and SEM analyses, highlight the role of nanowires in enhancing charge transfer and sustaining high-current performance. The presented 3D nickel-based configuration anode offers advancements in microbial fuel cell technology, providing a foundation for further enhancements and applications in energy harvesting systems.

Enhancing Robustness and Charge Transfer Kinetics of Sodium-Ion Batteries through Introduction of Anionic Anchoring Separators.

Ionic transport critically dictates the performance of the batteries. Here, we proposed an anion anchoring strategy for enhancing Na+ transport kinetics that was based on introducing a separator with a positive surface potential. Besides, we developed a nuclear magnetic resonance-assisted Hittorf approach to address the limitation of the traditional Bruce-Vincent approach itself in order to accurately quantify the migration dynamics of anions on the time scale. Results indicate that this strategy effectively anchors free anions and increases the proportion of solvent-separated ion pairs in the bulk, reduces the cation transfer energy barrier at the anode, and mitigates parasitic reactions at the cathode. The symmetric Na||Na cells efficiently operate over 1600 h, and the Na||Na3V2(PO4)3 cells show stable cycling performance under limited Na excess and lean electrolyte conditions. The assembled HC||Na3V2(PO4)3 pouch cells achieve an energy density of up to 225.7 W h kg-1. Our strategy offers a new option for high-energy and long-cycle sodium-ion batteries.

Enhanced charge transfer and kinetics in hydrogen production using CoS@NiS nanoparticle heterojunctions for clean energy

Enhanced charge transfer and kinetics in hydrogen production using CoS@NiS nanoparticle heterojunctions for clean energy

Enhanced charge transfer and coupled resonance in Ni-doped sub-stoichiometric tungsten oxide nanostructure for plasmon-free SERS sensing

Enhanced charge transfer and coupled resonance in Ni-doped sub-stoichiometric tungsten oxide nanostructure for plasmon-free SERS sensing

Enhanced charge transfer kinetics in supercapacitor electrodes: The synergistic effect of 2D Mo2Ti2C3 in PANI/MoO3 composite

Enhanced charge transfer kinetics in supercapacitor electrodes: The synergistic effect of 2D Mo2Ti2C3 in PANI/MoO3 composite

Improved optical, mechanical, and electrochemical performances of MWCNT/MnS-incorporated bioderived gel ternary nanocomposite

Nanocomposite film–based biodegradable gelatin (gel) polymer incorporated with multi-walled carbon nanotube (MWCNT) and manganese sulfide (MnS) nanoparticles has been fabricated by the solution casting technique. The diversity of different chemical groups in the gel/MWCNT/MnS ternary nanocomposite polymer has been investigated by Fourier transform infrared spectra. The DC resistivity of the gel/MWCNT/MnS reduces in comparison with the pure gel polymer. The inclusion of MWCNT and MnS remarkably enhances the tensile strength with an estimated value of 2.11 MPa. Due to the enhanced charge transfer phenomenon between layers and defect states, the optical bandgap of gel has been observed to be reduced from 4.91 to 4.37 eV while incorporating MWCNT and MnS nanofillers. The electrochemical energy storage performances of gel/MWCNT/MnS have been studied in the three-electrode configuration. The gel/MWCNT/MnS sample exhibits a maximum specific capacitance of 64.46 Fg−1 at 10 mV/s. In addition, the ternary nanocomposite exhibits the highest energy density of 38 Wh/g at specific power of 210 W/g and maximum specific power of 210 W/g at specific energy of 6.475 Wh/g. This work promotes possible strategies for improving the electrochemical performances of gel/MWCNT/MnS as an electrode material.

Accelerating Charge Transfer in Supercapacitor Electrodes through Built-In Electric Fields.

The commercial development of supercapacitors (SCs) heavily depends on a stable electrochemical performance with a long life span. However, insufficient charge transfer within the SC electrodes is a major challenge. This paper introduces an interface engineering strategy to enhance charge transfer by creating a built-in electric field (BIEF) at the interface of MXene electrode material. Ti3C2Tx MXene decorated with Ti2N nanocubes was selected as the electrode material, and a stable BIEF was formed at the Ti2N/Ti3C2Tx interface due to the different surface potentials of Ti2N and Ti3C2Tx. Our results show that the designed Ti2N/Ti3C2Tx electrode exhibits a high capacitance of 250.3 F g-1, an excellent rate capability of 63.6% at 20 A g-1, and an outstanding cycling stability of 95.8% at 10 A g-1 after 10,000 cycles in a three-electrode system. The assembled two-electrode device with activated carbon (AC) as the anode, the Ti2N/Ti3C2Tx//AC, demonstrates an excellent energy storage performance, with an energy density of up to 50.8 Wh kg-1 and an outstanding cycling stability of 96.77% over 10,000 cycles. The improved energy storage performance and cycling stability are attributed to the accelerated ion transportation and adsorption/desorption on the electrode surface, driven by the electric field force generated by the BIEF. In addition, the in-situ growth of Ti2N on the Ti3C2Tx surface is conducive to improving the structural stability of the electrode material and promoting the stable existence of the BIEF. This work provides a new pathway for developing ultrastable and high-performance SCs.

The Influence of PEABr Passivation Concentration, Light Exposure, and Temperature on the Electrochemical Behavior and Charge Transfer Resistance in MAPbBr3 Single Crystals

AbstractMethylammonium lead bromide (MAPbBr3) single crystals (SCs) showed promise for next‐generation optoelectronic devices due to their exceptional charge transport properties and ease of fabrication. However, surface passivation, light exposure, and temperature significantly influenced their electrochemical behavior, charge transfer resistance, and overall device performance. This study investigated the effects of phenylethylammonium bromide (PEABr) passivation concentration, varying light conditions, and temperature on the electrochemical properties of MAPbBr3 SCs. Results showed that increasing PEABr passivation concentration significantly enhanced charge transfer dynamics and reduced interfacial resistance. Passivation concentrations, particularly 20 mM and 50 mM, effectively reduced resistance and ion migration rates, enhanced charge carrier mobility, and minimized recombination losses. Charge transfer resistance exhibited a substantial dependence on passivation concentration and a moderate dependence on light type under various light exposures. The ion activation energy increased from 0.21 eV to 0.40 eV after passivation, indicating effective suppression of ion migration and improved electrochemical stability. Phase angle analysis from Bode plots further demonstrated enhanced charge transfer and capacitive behavior under all tested conditions with higher passivation concentrations. These findings highlighted the critical role of optimizing PEABr passivation concentration in reducing charge transfer resistance, enhancing charge carrier dynamics, and improving the electrochemical performance of MAPbBr3 SCs.

Electron-Phonon Coupling and Phonon Dynamics in Single-Layer NbSe2 on Graphene: The Role of Moiré Phonons.

The interplay between substrate interactions and electron-phonon coupling in two-dimensional (2D) materials presents a significant challenge in understanding and controlling their electronic properties. Here, we present a comparative study of the structural characteristics, phonon dynamics, and electron-phonon interactions in bulk and monolayer NbSe2 on epitaxial bilayer graphene (BLG) using helium atom scattering (HAS). High-resolution helium diffraction reveals a (9 × 9)0° superstructure within the NbSe2 monolayer, commensurate with the BLG lattice, while out-of-plane HAS diffraction spectra indicate a low-corrugated (3√3 × 3√3)30° substructure. By monitoring the thermal attenuation of the specular peak across a temperature range of 100 to 300 K, we determined the electron-phonon coupling constant (λHAS) as 0.76 for bulk 2H-NbSe2. In contrast, the NbSe2 monolayer on graphene exhibits a reduced λHAS of 0.55, corresponding to a superconducting critical temperature (TC) of 1.56 K according to the MacMillan formula, consistent with transport measurement findings. Inelastic HAS data provide, besides a set of dispersion curves of acoustic and lower optical phonons, a soft, dispersionless branch of phonons at 1.7 meV, attributed to the interface localized defects distributed with the superstructure period, thus termed Moiré phonons. Our data show that Moiré phonons contribute significantly to the electron-phonon coupling in monolayer NbSe2. These results highlight the crucial role of the BLG in the electron-phonon coupling in monolayer NbSe2, attributed to enhanced charge transfer effects, providing valuable insights into substrate-dependent electronic interactions in 2D superconductors.

Optimization of CdS/MoS2 Photocatalysts for Phonon-Enhanced H2 Evolution via Indirect Transition Modulation in Layer-Dependent MoS2.

Rational modulation in the transition distribution of electronic band structure is crucial for constructing phonon-induced enhancement effects for efficient charge separation and thus improving the photocatalytic activity of heterogeneous semiconductor systems. Herein, the indirect/direct transition modulation of layer-dependent MoS2 has been systematically investigated and modeled as a noble metal-free cocatalyst model to study the spatial behavior of carriers in the presence of the phonon effect by coupling it to the direct semiconductor CdS. Consequently, photocarrier separation at the heterojunction interface is greatly facilitated by the optimized band-matching mechanism, while phonon-interfered recombination achieves lifetime extension, which is further elucidated by theoretical simulations. Notably, the water reduction properties of the optimal CdS/MoS2 system exhibit a striking apparent quantum efficiency (31.33% at 380nm), with an H2 evolution rate as high as 9.70mmol h-1 g-1, which is 7.58 times higher than that of pristine CdS. Overall, this work demonstrates the capability of involved phonons for enhancing charge transfer dynamics, and provides great flexibility for precisely designing superior photocatalytic systems by manipulating the electronic band transformation.

Enhancing charge transfer in hybrid solar cells: the role of pulse laser-assisted hydrothermally synthesized Au@N-S-doped fluorescent carbon quantum dots as Forster Resonance Energy Transfer antennas

The strategic selection and design of antenna materials can significantly improve the light-harvesting efficiency of acceptor dye in Forster Resonance Energy Transfer (FRET)-based hybrid solar cells. This study uses innovative pulse laser-assisted hydrothermally synthesized Au-decorated nitrogen and sulphur-doped fluorescent carbon quantum dots (Au@NSCDs) as FRET relay antennas. They have unique properties, such as large surface areas for biomolecule attachment, broad spectral absorption, efficient charge carrier extraction, and rapid charge transport. We investigate hybrid solar cell integration with N3 dyes as energy acceptors and Au@NSCDs as donors. The study reveals the existence of FRET and the interaction between Au@NSCDs and the N3 dye. The FRET efficiency is 22.17%, while the Radiative Energy Transfer (RET) efficiency is 20%. Co-sensitization of Au@NSCDs with N3 dye in DSSCs leads to a 1.29% power conversion efficiency (PCE), 0.45 V open circuit voltage, a 1.77 mA/cm2 short-circuit current density, and a 30% improvement compared to TiO2/BaTiO3/N3-based DSSCs. Au@NSCDs also mitigate charge recombination, increasing open-circuit voltage to 670 mV. The TiO2/BaTiO3/N3-Au@NSCD configuration had an effective lifetime (17.57 ms), excellent charge carrier retention, and the highest charge collection efficiency (0.99). Au@NSCD antenna material can reduce charge recombination, indicating potential for future hybrid solar cell technology advancements.Graphical

Surface Nd Sites Boost Charge Transfer of Fe2O3 Photoanodes for Enhanced Solar Water Oxidation.

Photoelectrochemical (PEC) water splitting for hydrogen production is a promising technology for sustainable energy generation. In this work, we introduce Nd sites boost the PEC performance of Fe2O3 photoanodes through a precise gas-phase cation exchange process, which substitutes surface Fe atoms with Nd. The incorporation of Nd significantly enhances charge transfer properties, increases carrier concentration, and reduces internal resistance, leading to a substantial increase in photocurrent density from 0.44 to 0.92 mA cm-2 at 1.23 VRHE. Further enhancement of catalytic activity was achieved by depositing a NiCo(OH)x layer and a photocurrent density of 1.15 mA cm-2 at 1.23 VRHE were obtained. Theoretical calculations corroborate these experimental results, revealing that Nd doping narrows the bandgap, improves charge separation efficiency, and lowers the reaction potential barrier, thereby accelerating water oxidation kinetics. These findings underscore the effectiveness of surface cation exchange and targeted metallic element doping in overcoming the intrinsic limitations of Fe2O3, providing a viable pathway for developing high-performance PEC systems for efficient hydrogen production.