Efficient Electron Transport Research Articles

Ultrasensitive electrochemical detection of gallic acid in beverages based on nitrogen-doped multi-walled carbon nanotube networks embellished with cobalt 2-methylimidazole nanoparticles.

This work presents a convenient and easy-to-operate method for synthesizing the functionally integrated nanocomposite of nitrogen-doped multi walled carbon nanotube networks (N-CNTs) and cobalt 2-methylimidazole (ZIF-67) nanoparticles. The N-CNTs@ZIF-67 nanocomposite was utilized to design a novel electrochemical sensing platform for detecting gallic acid (GA). The N-CNTs@ZIF-67 modified glass carbon electrode (GCE) demonstrated high sensitivity for GA electrochemical detection (LOD: 10.17nM, detection concentration: 0.5-20μM). N-CNTs provided efficient electron transport channels for the GA electrochemical detection reaction, which improved the transfer rate of electrons/ions at the interface of sensing electrode/electrolyte. ZIF-67 nanoparticles with highly porous structure could adsorb GA molecules and promote the oxidation reaction. Besides that, N-CNTs provided more active sites on carbon nanotube networks by nitrogen-doping, which significantly enhanced the catalytic activity. The prepared N-CNTs@ZIF-67/GCE sensor exhibited favorable GA sensing detection performance, realizing an accurate analysis of GA in beverage samples (Recovery: 96.77-107.93%, RSD: 1.07-4.38%).

Electromechanics of the Molecule-Electrode Interface and Interface-Mediated Effects in Single-Molecule Junctions.

The molecule-electrode interface can regulate both the efficiency and pathways of electron transport through single-molecule junctions (SMJs). The electromechanics of the interface has proven crucial in exposing the underlying mechanisms of electron transmission through SMJs, providing a theoretical base and practical guidance for designing and constructing functional molecular devices. Here we encompass several currently developed methodologies for investigating the electromechanics of molecule-electrode interface and provide an account of their application in elucidating the effects of the molecule-electrode interface on electron transport properties of SMJs. This review will offer a comprehensive picture and new insights into developing single-molecule electromechanical devices and the progression of devices' mechanical stability toward large-scale integration.

Room-temperature spin-conserved electron transport to semiconductor quantum dots using a superlattice barrier.

To realize the optical transfer of electron spin information, developing a semiconductor layer for efficient transport of spin-polarized electrons to the active layers is necessary. In this study, electron spin transport from a GaAs/Al0.3Ga0.7As superlattice (SL) barrier to In0.5Ga0.5As quantum dots (QDs) is investigated at room temperature through a combination of time-resolved photoluminescence and rate equation analysis, separating the two transport processes from the GaAs layer around the QDs and SL barrier. The electron transport time in the SL increases for a thicker quantum well (QW) of SL due to the weaker wavefunction overlap between adjacent QWs. Additionally, the degree of conservation of spin polarization during transport varies with QW thickness. Rate equation analysis demonstrates an electron transport from SL to QDs while maintaining a high spin polarization for thick QWs. The achieved spin-conserved electron transport can be attributed to the combination of electron transport being sufficiently faster than the spin relaxation in SL and the suppressed spin relaxation in the p-doped GaAs layer capping the QDs. The findings indicate that SL is a promising candidate as an electron spin transport layer for optical spin devices.

Charge Polarity Modulation and Efficient Electron Transport in Quinoid–Donor–Acceptor Polymers by Acceptor Engineering for High-Performance Transistors

Charge Polarity Modulation and Efficient Electron Transport in Quinoid–Donor–Acceptor Polymers by Acceptor Engineering for High-Performance Transistors

Band alignment characterizations of grafted GaAs/(2¯01) Ga2O3 heterojunction via x-ray photoelectron spectroscopy

Research on gallium oxide (Ga2O3) has accelerated due to its exceptional properties, including an ultrawide bandgap, native substrate availability, and n-type doping capability. However, significant challenges remain, particularly in achieving effective p-type doping, which hinders the development of Ga2O3-based bipolar devices like heterojunction bipolar transistors (HBTs). To address this, we propose integrating mature III–V materials, specifically n-AlGaAs/p-GaAs as the emitter (E) and base (B) layers, with n-Ga2O3 as the collector (C) to form III–V/Ga2O3 n–p–n HBT. This hetero-material integration could be achieved using advanced semiconductor grafting techniques that could create arbitrary lattice-mismatched heterojunctions by introducing an ultrathin dielectric interfacial layer. This study focused on revealing the band alignment at the base–collector (B–C) junction using a n-Ga2O3(2¯01) orientated substrate combined with p-GaAs for potential HBT applications. We discovered a type-II band alignment between p-GaAs and Ga2O3(2¯01), with the p-GaAs conduction band approximately 0.614 eV higher than that of Ga2O3(2¯01). This staggered alignment allows for direct and efficient electron transport from the p-GaAs base to the n-Ga2O3 collector, avoiding the electron blocking issues present in p-GaAs/Ga2O3 (010) heterojunctions. Additionally, our study suggests the potentially existing type-II alignment between the (2¯01) and (010) Ga2O3 interfaces, highlighting the orientation-dependent band offsets. These findings are pivotal for developing high-performance Ga2O3-based HBTs, leveraging the strengths of Ga2O3 and well-established semiconductor materials to drive advancements in high-power electronics.

Self-Assembled Covalent Triazine Frameworks Derived N, S Co-Doped Carbon Nanoholes with Facilitating Ions Transportation Toward Remarkably Enhanced Oxygen Reduction Reaction and for Zinc-Air Batteries.

3D assembled carbon materials, featuring unique hierarchical porosity and interconnected channels, are essential for the advancement of emerging zinc-air batteries (ZABs). In this study, nitrogen (N) and sulfur (S) co-doped 3D carbon nanoholes (N/S-CNHs) are synthesized through a straightforward procedure involving self-assembly followed by carbonization. This process utilizes a hybrid of self-assembled covalent triazine framework and sodium lignosulphonate (CTF@LS) as a multifunctional precursor. The resulting N/S-CNHs exhibit a distinctive nanoholes microstructure composed of interwoven carbon nanoclusters, which facilitates efficient ion and electron transport during the electrocatalytic process. The incorporation of N and S atoms intriguingly alters the wetting properties of the catalyst microenvironment, thereby significantly facilitating the transfer of key intermediates and their interaction with the electrolyte. Consequently, the optimized N/S-CNH-900 demonstrates remarkable electrocatalytic activity for the ORR (E1/2 = 0.86V vs RHE), surpassing the performance of state-of-the-art Pt/C electrocatalyst. Theoretical calculations reveal that the synergistic effect of N and S heteroatom doping significantly enhances *OOH desorption and its transformation to O*, thereby markedly accelerating the ORR process. Furthermore, both liquid and quasi-solid ZABs equipped with the N/S-CNH-900 cathode exhibit improved peak power density and specific capacity relative to those employing commercial Pt/C catalysts.

Transition Metal Chalcogenides/Nonconjugated Polymer Artificial Photosystems for Photoredox Catalysis.

Surface charge transfer doping (SCTD) has been established as an efficient strategy to achieve strong electronic coupling interactions between semiconductors and dopants, which lead to highly efficient electron transport over semiconductors. Herein, we report a facile, easily accessible, and effective SCTD strategy to exquisitely modulate the interfacial charge transfer over transition metal chalcogenides (TMCs: CdS, Zn0.5Cd0.5S, CdIn2S4, and ZnIn2S4) through surface modification with a nonconjugated polymer, poly(dimethyldiallylammonium chloride) (PDDA). We provide evidence that PDDA, as a surface electron transfer acceptor, can be used to enable rapid, directional, and tunable charge transfer along with an optimal charge lifetime over TMCs in photoredox catalysis because of the high-efficiency electron-trapping property of quaternary ammonium functional groups in the molecular structure of PDDA. The thus-assembled PDDA-encapsulated TMC composite artificial photosystems demonstrate significantly enhanced and versatile photoredox catalytic activities toward visible-light-responsive photocatalytic reduction of aromatic nitro compounds, photocatalytic oxidation of aromatic alcohols, and photocatalytic H2 production, wherein the ultrathin PDDA layer accelerates the interfacial charge transport and separation rate over TMC substrates. Moreover, it was evidenced that such an interface engineering strategy is general for a collection of TMCs. Our work will provide conceptual insights into nonconjugated polymer-based artificial photosystems for optimizing solar energy utilization.

Terminal Effects of Fulleropyrrolidine Electron Transport Materials for Efficient Perovskite Solar Cells

AbstractFullerene (C60) and its derivatives are the most prevalent and efficient electron transport materials (ETMs) for state‐of‐the‐art perovskite solar cells (PSCs). Benefiting from the high performance, simple synthesis, and easy availability of raw materials, fulleropyrrolidine derivatives (FDs) are potential next‐generation ETM alternatives to currently used fullerene materials. However, the power conversion efficiency (PCE) of FDs still lags far behind that of methanofullerene derivatives such as [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM). Moreover, the underlying mechanism remains unclear. In this work, six FD ETMs are designed and synthesized, i.e., CN‐TPAX (X = H, Me, OMe, Cl, Br, I), for p‐i‐n PSCs, and obtained a champion PCE of over 25% for the CN‐TPACl ETM, outperforming all reported FDs until now. Subsequently, their performance is systematically characterized in terms of molecular characteristics, including single‐crystal structure, electronic properties, film formability/morphology, and electron dynamics, which helped reveal the terminal effects of FD ETMs on the molecular characteristics and photovoltaic performance of PSCs. This approach clarified the structure–performance relationships between the FDs and the resulting devices, highlighting the importance of the terminal design of fullerene ETMs for high‐performance PSCs.

Mitigating the interface defects influence on SnSe solar cells using optimized electron transport layer

The field of photovoltaics relies heavily on compound semiconductors, particularly those based on selenium. However, challenges in maintaining stoichiometry and the scarcity of elements like Indium and Gallium hinder their widespread adoption. Tin monoselenide (SnSe) emerges as a promising alternative to silicon, thanks to its favorable properties, including a high absorption coefficient, suitable band gap, and excellent chemical stability. Additionally, SnSe exhibits superior thermal stability and can maintain efficiency under a wider range of operating conditions. Its unique crystal structure allows for enhanced charge carrier mobility, facilitating better performance in thin-film applications. These attributes collectively position SnSe as a highly competitive material in the pursuit of efficient and reliable solar energy solutions. Despite its potential, there is a lack of research on low-efficiency solar cells based on SnSe, highlighting the need for further exploration. Our study advocates for a theoretical investigation into the factors affecting SnSe-based solar cell efficiency, focusing on loss mechanisms like bulk and interface recombination. We propose an analytical model that examines various recombination mechanisms and their interactions to enhance efficiency. Experimental results validate our model, revealing the pivotal role of recombination mechanisms at both bulk and interface levels. Besides, the suggested model is used as a fitness function for the Multi Objective Particle Swarm Optimization (MOPSO) technique to identify the optimal combination of design parameters that produced the highest efficiency. The optimized design with In2O3 and MgZnO as Electron transport layer (ETL) materials surpasses current efficiency limitations and explore efficient Cd-free electron transport layer with suitable band alignment. Overall, our strategy by combining analytical model with optimization technique provides insights and solution for enhancing SnSe-based solar cell efficiency, to exceed 13%.

Enhanced photovoltaic performance and longevity of perovskite modules via interface engineering of transport layer

Abstract This research presents interfacial engineering of large–area perovskite modules. The quality of the interface between the electron transport layer(ETL) and the perovskite layer are studied, because it significantly affects the optoelectronic performance of large–area module devices. In large–area fabrication, film uniformity and interfacial quality are critical, as the ETL/perovskite interface governs both electron extraction and transport efficiency, while also affecting the uniformity and crystallinity of the perovskite. To overcome these issues, using picosecond laser technique (P1,P2,P3) to fabricate large–area modules, integrating monolithic cells in series. Planar SnO2 and mesoporous TiO2 ETL are prepared. Results show that meso–type ETL structures are better suited for large–area modules. The modules with meso–type TiO2 exhibit fewer shunting issues and stronger emission in electroluminescence images. Photoluminescence mapping indicates improved structural uniformity of perovskite. The perovskite module with meso–type TiO2 achieve power conversion efficiency of 18.2% (4cm2) and maintain 80% of initial efficiency after 700 hours.

Embedding Pt in Ni-MOF/CdS organic-inorganic hybrid materials as electron channel to promote photogenerated carrier separation for enhanced photocatalytic hydrogen evolution under visible light

CdS exhibits a high photogenerated carrier yield, yet it is susceptible to photocorrosion due to the limited number of active sites. Ni-MOF boasts a considerable specific surface area and a plethora of active sites, yet it displays a low photogenerated carrier yield and suboptimal conductivity. In this study, the incorporation of Pt into a Ni-MOF/Pt/CdS hybrid material served as an electron transport channel, effectively addressing the limitations of CdS, Ni-MOF, and electrical conductivity. The results of electrochemical tests demonstrate that the electron transport and separation efficiency of the hybridised material is noteworthy. Following the performance test, the optimal visible photocatalytic hydrogen evolution rate of the Ni-MOF/Pt/CdS hybrid material was found to be 14.1 mmol h−1g−1, representing a significant enhancement of approximately 61.3 times compared to that of pure CdS. Furthermore, XPS analysis indicates the presence of Pt-S bonds, which effectively inhibit the oxidation of S2− to S on the CdS surface, thus alleviating the photocorrosion phenomenon and enhancing the cycling stability. This level of stability is maintained at 92.6 % after five cycles. This work offers a novel approach to addressing the limitations of inorganic catalysts, including the scarcity of active sites and the low photogenerated carrier yield, as well as the poor conductivity observed in organic catalysts.

Efficient photo-assisted reduction of Cr(VI) via activated carbon mediated Z-scheme FeS2/α-FeOOH/C heterojunction: Focusing on molecular oxygen fate and synergetic reduction mechanism

Herein, pyrite (FeS2), goethite (α-FeOOH) and activated carbon (C) were combined to construct FeS2/α-FeOOH/C composites with C mediated Z-scheme heterojunction for efficient photo-assisted Cr(VI) reduction. Characterization tests indicated the strong interaction via Fe-O-C and C-S-C, the increased amount of crystal defects and surface oxygenic functional groups, and the decreased agglomeration degree during combination strengthened electron transport and visible light conversion efficiency, resulting in synergistic effect for enhanced Cr(VI) removal. Additionally, C mediated Z-scheme heterojunction with lower resistance facilitated the transfer and separation efficiency of photo-generated carriers, further accelerating Cr(VI) reduction. Consequently, almost 100 % of Cr(VI) was reduced via FeS2/α-FeOOH/C in 60 min, 4 times that of pristine FeS2. Quenching, EPR and control experiments confirmed photocatalysis made more contribution than single reductive reagents (FeS2) in Cr(VI) reduction. The specific contribution rate of reductive species like e−, Fe2+, S22− and •O2− in this complicated system was firstly detailedly demonstrated and •O2− played a predominant role under oxic condition. Meanwhile, oxidative species like H2O2, 1O2 and •OH ascribed to DO activation or photo-generated h+ preferred to reacted with Fe2+ and S22− with higher reducibility and-only delayed Cr(VI) reduction rate. Hence, the final total Cr(VI) removal efficiency and generated Cr(III) kept stable in oxic solution.

Laser-Induced Graphene Decorated with MOF-Derived NiCo-LDH for Highly Sensitive Non-Enzymatic Glucose Sensor.

Designing and fabricating a highly sensitive non-enzymatic glucose sensor is crucial for the early detection and management of diabetes. Meanwhile, the development of innovative electrode substrates has become a key focus for addressing the growing demand for constructing flexible sensors. Here, a simple one-step laser engraving method is applied for preparing laser-induced graphene (LIG) on polyimide (PI) film, which serves as the sensor substrate. NiCo-layered double hydroxides (NiCo-LDH) are synthesized on LIG as a precursor, utilizing the zeolitic imidazolate framework (ZIF-67), and then reacted with Ni(NO3)2 via solvent-thermal methods. The sensitivity of the non-enzymatic electrochemical glucose sensor is significantly improved by employing NiCo-LDH/LIG as the sensing material. The porous and interconnected structure of NiCo-LDH, derived from ZIF-67, enhances the accessibility of electrochemically active sites, while the incorporation of LIG ensures exceptional conductivity. The combination of NiCo-LDH with LIG enables efficient electron transport, leading to an increased electrochemically active surface area and enhanced catalytic efficiency. The fabricated electrode achieves a low glucose detection limit of 0.437 μM and demonstrates a high sensitivity of 1141.2 and 631.1 μA mM-2 cm-2 within the linear ranges of 0-770 μM and 770-1970 μM, respectively. Furthermore, the NiCo-LDH/LIG glucose sensor demonstrates superior reliability and little impact from other substances. A flexible integrated LIG-based non-enzymatic glucose sensor has been developed, demonstrating high sensitivity and suggesting a promising application for LIG-based chemical sensors.

Strategic defect engineering in TiO2 catalysts through electron beam irradiation: Unraveling enhanced photocatalytic pathways for multicomponent VOCs degradation

Defect engineering improves catalytic activity, electron transport efficiency, and stability by introducing defects such as oxygen vacancies, offering significant potential for applications in environmental remediation and energy conversion. Electron beam (EB) irradiation has emerged as a key technique in defect engineering, renowned for its mild reaction conditions and precise defect construction capabilities. This study synthesized defect-rich commercial TiO2 catalysts (P25) using high-energy EB irradiation to investigate the photodegradation efficiency of multicomponent VOCs. The EB irradiation technique promoted the formation of oxygen vacancies, which played a key role in the adsorption and activation of pollutant molecules. DFT calculations further confirmed the superior photocatalytic activity of the irradiated P25 catalyst. The photodegradation experiments showed that the 300P25 degraded pure ethyl acetate up to 99.05 % (40 min) and acetone up to 97.14 % (60 min), but toluene only up to 7.34 % (60 min). Interestingly, in acetone and toluene mixture, 300P25 achieved toluene removal as high as 68 % (60 min) with a rate constant (k) of 0.0181 min−1, a 12.1-fold than pure toluene (0.0015 min−1). In-situ infrared spectroscopy analysis revealed that during the simultaneous degradation of toluene and acetone, acetone significantly promoted the deep oxidation of toluene, leading to the rapid oxidation of intermediate products (benzyl alcohol and benzaldehyde) to benzoic acid and smaller molecules. This work provides important guidance for developing efficient and stable photocatalysts for degrading multicomponent VOCs.

Interface dipole evolution from the hybrid coupling between nitrogen-doped carbon quantum dots and polyethylenimine featuring the electron transport thin layer at Al/Si interfaces

The assessment of electron transport layer (ETL) for rear-contact engineering of silicon (Si) based optoelectronics has been considered as one of the critical challenges that leverage the performance improvement and device reliability. In this work, the hybrid design of ETL, obtained from the solution-processed nitrogen-doped carbon quantum dots (NCQDs) incorporated with organic polyethylenimine (PEI) demonstrates the feasible contact characteristics for the modification of Si/Al contacts, which greatly facilitates the transport and collection of photoexcited electrons in the Si-based optoelectronics. The aspects of microstructures, functional groups, chemical features, interfacial characteristics and band structures of NCQD/PEI are explicated, visualizing that the evolution of interface dipoles mediated by the overall outcome of physisorption and chemisorption effects, modifies the surface potential difference and results in the explicit reduction of the Al work function from 4.3 eV for pristine Al to 3.23 eV based on the optimized constitutional design (0.10 % NCQD in PEI). These findings are practically employed on the Si-based hybrid solar cells at Si/Al interfaces, fulfilling the conversion-efficiency improvement by 30.9 % compared with reference cells without ETL employment, which are experimentally interpreted by the efficient electron transport across the Si/Al heterojunction and charge collection.

Hierarchical Dual-Carbon Anode and Cathode Derived from Zeolitic Imidazolate Frameworks Grown on 3D Graphene Oxide Aerogels for Ultrahigh-Performance Potassium-Ion Hybrid Energy Storage Systems

A potassium-ion hybrid system has been shown to be highly suitable for dual-mode applications as both a battery and a supercapacitor, once the issues of slow kinetics in the anode and low capacity in the cathode are addressed. In this study, we design a Potassium-ion hybrid energy storage (PIHES) system that excels in both rapid charging and high energy density. The PIHES full cells are developed using zeolitic imidazolate frameworks (ZIFs) grown on 3D graphene oxide aerogels (RGOAs). These microporous ZIFs on 3D RGOAs form a Zn-embedded hierarchical porous graphitic carbon anode material. Sub-nanometer Zn particles in the anode facilitate rapid faradaic reactions, as confirmed by operando X-ray diffraction studies combined with kinetic analysis. The hierarchical structure of the material, with its porosity and graphitization, promotes the efficient transport of ions and electrons. First-principles density functional theory calculations reveal the underlying mechanism of potassium's superior adsorption behavior on sub-nanometer Zn nanoparticles compared to other materials, resulting in high-rate capability. The Zn-embedded ZIF-derived hierarchical porous carbon (ZZHPC) offers approximately twice the capacity of pristine ZIFs. Our cathode materials are derived from the graphitic carbon production and Zn evaporation from ZIFs on 3D RGOAs, featuring N-rich microporous sites for high capacity, excellent electrolyte wettability, and mesoporous graphitic carbon channels for rapid ion and electron transport. Our potassium-ion hybrid capacitor, utilizing a ZZHPC anode and a ZIF-derived hierarchical porous carbon (ZHPC) cathode, achieves an unprecedented energy density of 207.5 Wh kg-1 and a fast-chargeable power density of 21,500 W kg-1, while maintaining nearly 100% Coulombic efficiency over 10,000 cycles.

Microstructure, Charge Transport and Interfaces in All-Solid-State Batteries

Objective: Despite recent global efforts to establish all-solid-state batteries (ASSB) as potentially safe and stable high-energy and high-speed storage technology, long-term performance, specific power, and economic viability remain challenging. However, efficient and short ionic and electronic transport pathways and optimized interfacial contacts between the cell materials and compounds are essential. This poses a significant challenge for the microstructure of cathodes and a careful design and tailoring of anodes and separators in ASSB, which rely solely on solid-state contacts. Here, we present our recent work on ASSB with thiophosphate electrolytes conducted within the German Competence Cluster for Solid-State Batteries (FestBatt). Our work aims to investigate relevant parameters in different cell components on material, electrode, and cell level, such as the importance of particle size distributions, microstructures, and kinetic factors to optimize ASSB cathodes, separators, and anodes. Methodology: The work will be presented in four sections, which showcase key challenges as well as optimization strategies mainly focusing on cathode composites, but also discussing selected examples for separators and anodes in ASSB with thiophosphate electrolytes. Further, an outlook for relevant production steps of ASSB electrodes and cells will be given. For these studies, we mainly conducted focused ion beam scanning electron microscopy tomography, electrochemical impedance spectroscopy, cycling experiments on ASSB cells with thiophosphate solid electrolytes. Results: Fast conducting solid electrolytes are necessary to ensure sufficient transport in composite cathodes but does not represent the only key factor for high-quality cathode composites in ASSB. In our studies, we aimed to optimize the microstructure of composite cathodes consisting of intercalation-type active material and a thiophosphate-based solid electrolyte. We varied the particle size distribution of the solid electrolyte to create various cathode microstructures and assessed the effectiveness of electronic and ionic conduction pathways using partial conductivities. We used both electronically and ionically blocking electrodes for electrochemical impedance spectroscopy measurements to quantify the respective partial conductivities. Our analysis revealed that the particle size of the solid electrolyte significantly influences the charge transport and electrochemical performance of the cathodes. Additionally, using FIB-SEM tomography, we created detailed 3D reconstructions of the cathode microstructure and correlated the obtained partial conductivities with microstructural descriptors such as tortuosity factors, identifying possible kinetic bottlenecks. We found that minimizing residual porosity, which blocks ion and electron transport, is necessary to optimize cathode microstructures and enhance ASSB performance. Moreover, high-performance anodes, along with protective concepts, are crucial for establishing dense, high-energy ASSB cells. Lithium metal anodes may not be the ultimate solution, and silicon anodes can pose advantages, e. g. in terms of electrochemical stability for thiophosphate separators. Discussion: Our studies demonstrate the importance of optimizing the microstructure of cathodes and carefully designing Si anodes for improved ASSB cells. By manipulating the particle size distribution of the solid electrolyte, we achieved more efficient electronic and ionic transport pathways, leading to improved battery performance. The presented work is primarily published in references 1-5, detailing key challenges and showcasing optimization strategies for these topics. Beyond that, diversity in materials, research teams, and approaches is crucial for long-term successful development of ASSB. Acknowledgement: Scientific and administrative coordination of the BMBF Competence Cluster for Solid-State Batteries (FestBatt), FB2-Koord (03XP0431), and cell platform Thiophosphates, FB2-Thio (03XP0430A).

Zn-Sn Alloy Seed Layer-Coated Cu Current Collector for Anode-Free Aqueous Zn Ion Batteries

Zn ion batteries (ZIB) stand at the forefront of alternative advanced energy storage technologies due to the intrinsic properties of Zn, including its low reduction potential (-0.76 V vs. SHE), and high theoretical specific capacity (820 mAh g-1) acquired by its multi-electron redox processes. Nonetheless, the utilization of current thick Zn foil anode remains a big challenge to commercialization, caused by the dendrite growth, severe surface side reaction, and high N/P ratio, which leads to the limitation of cell energy density. Herein, we report anode-free technology based on ultra-thin Zn-Sn alloy seed layer-coated Cu foil (ASL@Cu), to break through the limit of cell energy density. Incorporating Sn and carbon in the seed layer results in a strong affinity towards Zn, inhibiting the irreversible surface reactions, and eventually offering efficient electron transport routes. The resulting ASL showed rapid kinetics for Zn2+ deposition (lower nucleation overpotential) and exhibited an extended cycle life at a current density of 4 mA cm-2. This work sheds light on the strategic design of anode-free to achieve outstanding performance with a constrained amount of Zn on the Cu current collector.

DFT Analysis on Adipic Acid to Propel Creative Advancements in Supercapacitor Technology

The increasing dependence on non-renewable resources for energy storage has accelerated the development of supercapacitor technology, which is now essential to portable devices and electric cars because of its high-power density and quick charge/discharge speed. Optimized geometry, weak C-H‧‧‧O hydrogen bonding interactions inside methylene groups affect bond lengths, and the carboxylic group in adipic acid (ADPI) shortens bond lengths (C14–C15 and C4–C5). DFT simulations demonstrate a fair agreement to experimental data. According to vibrational studies, the O-H and C=O groups' vibrational frequencies are greatly influenced by the reactive hydrogen bonding displayed by the -COOH group in carboxylic acid derivatives. With theoretical values demonstrating significant PED contributions, these interactions reduce the O-H stretching frequency, which is seen as an O-H stretching band at 3405 cm⁻¹ in the FT-IR spectra. In ADPI, atoms interact with neighboring atoms' σ* orbitals (O2-C4), (O12-C14), (C4-C5), (C14-C15), (O1-C4), and (O11-C14) through lone pairs of electrons localized on O1 (LP2), O11 (LP2), O2 (LP1), and O12 (LP1); these interactions have fairly high stabilization values of 33.78, 33.78, 17.91, 17.91, 6.75, and 6.75 kcal/mol, accordingly. Redox peaks and increased specific capacitance with scan rate are revealed by cyclic voltammetry study of ADPI, suggesting efficient electron transport, improved charge storage, and encouraging prospects for electrochemical energy storage applications. ADPI's appropriateness for high-performance electrochemical applications such as supercapacitors is supported by its impedance analysis, which is displayed by a Nyquist plot with a decreased semicircle and a sharp low-frequency slope. This plot demonstrates effective electron transfer, ion diffusion, and capacitive behavior.

Efficient Photocatalytic Hydrogen Production Using In-Situ Polymerized Gold Nanocluster Assemblies.

Gold nanoparticles (NPs) are widely recognized as co-catalysts in semiconductor photocatalysis for enhancing hydrogen production efficiency, but they are often overlooked as primary catalysts due to the rapid recombination of excited-state electrons. This study presents an innovative gold-based photocatalyst design utilizing an in situ dopamine polymerization-guided assembly approach for efficient H2 generation via water splitting. By employing gold superclusters (AuSCs; ≈100nm) instead of ultra-small gold nanoclusters (AuNCs; ≈2nm) before polymerization, unique nanodisk-like 3D superstructures consisting of agglomerated 2D polydopamine (PDA) nanosheets with a high percentage of uniformly embedded AuNCs are created that exhibit enhanced metallic character post-polymerization. The thin PDA layer between adjacent AuNCs functions as an efficient electron transport medium, directing excited-state electrons toward the surface and minimizing recombination. Notably, the AuSCs@PDA structure shows the largest potential difference (26.0mV) compared to AuSCs (≈18.4mV) and PDA NPs (≈14.6mV), indicating a higher population of accumulated photo-generated carriers. As a result, AuSCs@PDA achieves a higher photocurrent density, improved photostability, and lower charge transfer resistance than PDA NPs, AuSCs, or AuNCs@PDA, with the highest hydrogen evolution rate of 3.20mmol g-1h-1. This work highlights a promising in situ polymerization strategy for enhancing photocatalytic hydrogen generation with metal nanoclusters.