Enhanced Electron Transfer Research Articles

Visible-light-driven peroxydisulfate activation by biochar-loaded Fe-Cu layered double hydroxide for penicillin G degradation: Performance, mechanism and application potential

The biochar-loaded Fe-Cu layered double hydroxide (FeCu-LDH@BC) catalyst was synthesized via a simple hydrothermal method and used to activate peroxydisulfate (PDS) for penicillin G (PG) degradation under visible light. The physicochemical properties of FeCu-LDH@BC were characterized using SEM, XPS, UV-DRS, SEM-EDS, HRTEM, XRD, BET, PL spectrum, FT-IR, Raman spectrum, TG-DSC, TPD, and EIS, showing that biochar (BC) enhanced the optical properties of FeCu-LDH. Notably, the FeCu-LDH@BC+PDS+Light system achieved a 98.79% degradation efficiency for PG in just 10 min. Furthermore, FeCu-LDH@BC retained excellent activity after four reuse cycles. LSV results indicated enhanced electron transfer in the FeCu-LDH@BC+PDS+Light system, suggesting a synergistic effect between the photocatalytic and PDS activation systems. The interconversion of h+, SO4·-, 1O2, and ·OH species was found to play a key role in PG degradation. Density functional theory was used to identify PG sites susceptible to radical attack, and the possible degradation pathway was proposed based on liquid chromatography-mass spectrometry results. Toxicity evaluation using the TEST software confirmed that the intermediates formed were significantly less toxic than PG. Lastly, the FeCu-LDH@BC+PDS+Light system removed 37.45% of total organic carbon and 63.74% of chemical oxygen demand from real wastewater within 120 minutes. The type and transformation pathways of organic matter in the wastewater were analyzed using 3D Excitation Emission Matrix spectroscopy to assess the system’s application potential.

Facile synthesis of Co/Fe bimetallic doped Ni3S2 nanosheets and supercapacitor performance

Ni3S2 is an outstanding electrode material due to its high theoretical specific capacity, however, in practical research, the higher theoretical capacity is difficult to show, and the change of the structure in the cycling process affects the cycling stability, which limits its practical application. To address these issues, this study presents a strategy to synthesize Fe and Co bimetallic doped Ni3S2 nanosheets on nickel foam (NF) surface. This strategy introduces bimetallic atoms quickly and easily while synthesizing nanosheet structures, and the resulting synergistic interactions between the bimetals and the mutual support effect of the nanosheets can effectively enhance electron transfer and improve cycling stability. The electrochemical results show that the Fe and Co-doped sample (Ni3S2-Co/Fe-5) exhibits a specific capacitance of 3351 F·g−1 at 1 A·g−1 in the three-electrode system, which is nearly five times higher than the specific capacity of the undoped Fe and Co-doped sample (Ni3S2), and the capacity retention rate after cycling 5000 cycles at a current density of 10 A·g−1 is 100 %, the prepared sample (Ni3S2-Co/Fe-5) was assembled with activated carbon (AC) to form a hybrid supercapacitor, which could provide a maximum power density of 9818 W·kg−1, a maximum energy density of 66.25 Wh·kg−1, and a capacity retention of 94.5 % after 10,000 cycles, with a capacity loss of only 5.6 %.

Silica-coated nano zero-valent iron as a slow-release electron donor for sustained enhancement of aerobic denitrification in oligotrophic source water: Performance and mechanism

Limited organic carbon in drinking water constrains the removal of nitrate‑nitrogen (NO3−-N) via aerobic denitrification. This paper reports the use of silica-coated nano zero-valent iron (nZVI@SiO2) as a stable and sustainable electron donor to enhance aerobic denitrification. The nZVI@SiO2, synthesized via a one-step method, was resistant to oxidation and exhibited excellent stability. In conjunction with aerobic denitrifying bacteria, nZVI@SiO2 achieved NO3−-N and total nitrogen TN removal efficiencies of 90.64 % and 80.94 %, respectively. This represents an increase of 24.15 % in the efficiency of TN removal compared with that of the nZVI system. The activity of the nZVI system diminished gradually after just three cycles, whereas nZVI@SiO2 maintained NO3−-N and TN removal efficiencies of 89.33 % and 78.08 %, respectively, after four cycles, respectively, indicating its sustainable ability to enhance aerobic denitrification. Cyclic voltammetry and electrochemical impedance spectroscopy demonstrated enhanced electron transfer efficiency of nZVI@SiO2. Furthermore, nZVI@SiO2 significantly promoted the activity of the electron transfer system, ATP levels, nitrate/nitrite reductase activity, contents of complexes I and III, and extracellular polymeric substances. nZVI@SiO2 significantly enhanced electron generation, transfer, and consumption during biological denitrification by functioning as both an electron donor and mediator. The findings implicate nZVI@SiO2 as a means to enhance nitrogen removal by aerobic denitrifying microorganisms in oligotrophic water via sustained donation of electrons.

Effect of Synthesis Conditions on the Structure and Electrochemical Properties of Vertically Aligned Graphene/Carbon Nanofiber Hybrids

In recent years, significant efforts have been dedicated to understanding the growth mechanisms behind the synthesis of vertically aligned nanocarbon structures using plasma-enhanced chemical vapor deposition (PECVD). This study explores how varying synthesis conditions—specifically hydrocarbon flow rate, hydrocarbon type, and plasma power—affect the microstructure, properties, and electrochemical performance of nitrogen-doped vertically aligned graphene (NVG) and nitrogen-doped vertically aligned carbon nanofibers (NVCNFs) hybrids. It was observed that adjustments in these synthesis parameters led to noticeable changes in the microstructure, with particularly significant alterations when changing the hydrocarbon precursor from acetylene to methane. The electrochemical investigation revealed that the sample synthesized at higher plasma power exhibited enhanced electron transfer kinetics, likely due to the higher density of open edges and nitrogen doping level. This study contributes to better understanding the PECVD process for fabricating nanocarbon materials, particularly for sensor applications.

Enhancing the Efficiency and Stability of Perovskite Solar Cells Via Hybrid Electron Transport Layer Strategy.

Tin oxide (SnO2) is extensively employed as the electron transport layer (ETL) for perovskite solar cells, but the presence of unsaturated Sn dangling bonds and oxygen vacancy defects at surface hinders effective carrier transport. Herein, we present an effective strategy for constructing a hybrid ETL by doping ZnF2 into the SnO2, effectively addressing the oxygen vacancy defects at both the bulk and interface of SnO2, thus markedly minimizing nonradiative recombination losses. Additionally, the process-induced strong bonding between F and Sn atoms facilitates the establishment of electron transfer pathways, leading to an increased electron cloud density within SnO2 and enhanced electron transfer capability, thus further suppressing charge accumulation at the interface. The hybrid ETL strategy can be adaptable to perovskites with various cations. The MAPbI3 and Cs0.1FA0.9PbI3 perovskite solar cells achieved remarkable PCEs of 21.31% and 24.91%, respectively. Moreover, the hybrid ETL design significantly enhances device stability. After 600 h of ambient storage, the unencapsulated optimized devices retained approximately 90% of their initial efficiency.

Schottky Interface Engineering in Ti3C2Tx/ZnS Organic Hydrogels for High‐Performance Multifunctional Flexible Absorbers

AbstractWith the rapid advancement of wearable electronics, soft robotics, and camouflage technologies, there is an urgent demand for flexible, multifunctional electromagnetic wave absorbing materials. Traditional absorbers, including metal‐ and carbon‐based materials, often lack the flexibility required for such applications. In this work, a novel strategy is proposed for developing a flexible absorber by combining a conductive filler with a Schottky heterogeneous interface and a polymer network framework. Ti3C2Tx MXene is modified with ZnS via a low‐temperature hydrothermal method, forming a Ti3C2Tx/ZnS composite. This composite is subsequently embedded in a copolymer matrix of polyvinyl alcohol (PVA) and acrylamide (AAm), dispersed in a binary water‐glycerol solution. The Schottky interface between Ti3C2Tx and ZnS enhances electron transfer at the heterophase boundary, significantly improving interface polarisation. Simultaneously, interactions between water and glycerol restrict the rotation of polar molecules under external electromagnetic fields, optimising polarisation loss within the gel. Experimental results demonstrate that the Ti3C2Tx/ZnS gel achieves a minimum reflection loss (RLmin) of −43.76 dB at 8.79 GHz, with an effective absorption bandwidth (EAB) covering the entire X‐band. Additionally, the gel exhibit exceptional stretchability, frost resistance, shape adaptability, and photothermal conversion properties.

Electronic Modulation and Symmetry‐Breaking Engineering of Single‐Atom Catalysts Driving Long‐Cycling Li−S Battery

AbstractDeveloping efficient and durable single‐atom catalysts is vitally important for the sulfur redox reaction (SROR) in Li−S battery, while it remains enormous challenging. Herein, undercoordinated Ni−N3 moieties anchored on N,S‐codoped porous carbon (Ni−NSC) is obtained to enhance the SROR. The experiments and theoretical calculations indicate that the symmetry‐breaking charge transfer in Ni single‐atom catalyst originates from tuning effect of sulfur atoms mediated Ni−N3 moieties, which can both facilitate the chemical adsorption by formation of N−Ni⋅⋅⋅Sn2−, and achieve a rapid redox conversion of polysulfides because of the enhanced electron transfer. As results, the Ni−NSC based Li−S battery delivers a very high initial reversible capacity (1025 mAh g−1 at 1 C), as well as outstanding cycling‐stability for 2400 cycles at 2 C and 3 C, respectively. Noteworthy, the areal capacity can reach 7.8 mAh cm−2 at 0.05 C and a retention capacity of 4.7 mAh cm−2 after 100 cycles at 0.2 C for Ni−NSC based Li−S battery with sulfur loading of 5.88 mg cm−2. This work provides profound insight for rational optimizing microscopic electronic density of active site to promoting SROR in metal‐sulfur batteries.

Electronic Modulation and Symmetry-Breaking Engineering of Single-Atom Catalysts Driving Long-Cycling Li-S Battery.

Developing efficient and durable single-atom catalysts is vitally important for the sulfur redox reaction (SROR) in Li-S battery, while it remains enormous challenging. Herein, undercoordinated Ni-N3 moieties anchored on N,S-codoped porous carbon (Ni-NSC) is obtained to enhance the SROR. The experiments and theoretical calculations indicate that the symmetry-breaking charge transfer in Ni single-atom catalyst originates from tuning effect of sulfur atoms mediated Ni-N3 moieties, which can both facilitate the chemical adsorption by formation of N-Ni⋅⋅⋅Sn 2-, and achieve a rapid redox conversion of polysulfides because of the enhanced electron transfer. As results, the Ni-NSC based Li-S battery delivers a very high initial reversible capacity (1025 mAh g-1 at 1 C), as well as outstanding cycling-stability for 2400 cycles at 2 C and 3 C, respectively. Noteworthy, the areal capacity can reach 7.8 mAh cm-2 at 0.05 C and a retention capacity of 4.7 mAh cm-2 after 100 cycles at 0.2 C for Ni-NSC based Li-S battery with sulfur loading of 5.88 mg cm-2. This work provides profound insight for rational optimizing microscopic electronic density of active site to promoting SROR in metal-sulfur batteries.

The Electron‐Rich Interface Regulated MBene by S‐Bridge Guided to Enhance Nitrogen Fixation under Environmental Conditions

AbstractThe underutilization of active sites limits the performance enhancement of 2D transition metal boride (MBene) in electrocatalytic nitrogen reduction reaction (NRR). Herein, a highly efficient NRR electrocatalyst with S atoms bridging Fe and Mo atoms on the surface of MBene is successfully constructed by using an active site electron optimization strategy, which increases the charge density around the Mo active site and enhances the activation ability of the catalyst to N2 molecules. It is noteworthy that FeS2‐MBene demonstrates a low intrinsic potential for NRR (−0.2 V vs RHE). It is more favorable for the adsorption of nitrogen atoms in comparison to hydrogen atoms, thereby it can effectively inhibit the hydrogen evolution reaction (HER). Under a potential of −0.2 V versus RHE, the ammonia yield rate is 37.13 ± 1.31 µg h−1 mg−1, and the FE is 55.97 ± 2.63%. Density functional theory (DFT) calculations demonstrate that Mo on the surface of MBene serves as a site for the adsorption of N2. The formation of the heterostructure enhances electron transfer, resulting in the Mo active site becoming an electron‐rich state in favor of subsequent hydrogenation steps. This work offers significant insights into the design and utilization of 2D MBene‐based catalysts in NRR.

Self-Etching Synthesis of Superhydrophilic Iron-Rich Defect Heterostructure-Integrated Catalyst with Fast Oxygen Evolution Kinetics for Large-Current Water Splitting.

Developing catalysts with rich metal defects, strong hydrophilicit, and extensive grain boundaries is crucial for enhancing the kinetics of electrocatalytic water oxidation and facilitating large-current water splitting. In this study, we utilized pH-controlled etching and gas-phase phosphating to synthesize a flower-like Ni2P-FeP4-Cu3P modified nickel foam heterostructure catalyst. This catalyst features pronounced hydrophilicity and a high concentration of Fe defects. It exhibits low overpotentials of 156 mV and 210 mV at current densities of 10 and 100 mA cm-2 respectively, and maintains stability for up to 200 h at 100 mA cm-2 with only 7.3% degradation, showcasing outstanding electrocatalytic water oxidation performance. Furthermore, when integrated into a Ni2P-FeP4-Cu3P/NF||Pt-C/NF electrolyzer, it achieves excellent overall water splitting performance, reaching current densities of 10 and 400 mA cm-2 at just 1.47 V and 1.73 V, respectively, and operates stably for 60 h at 500 mA cm-2 with minimal degradation. Analysis indicates that high-valence oxyhydroxides/phosphides of Ni, Fe, and Cu act as the primary active species. The presence of abundant Fe defects enhances electron transfer, strong hydrophilicity improves electrolyte contact, and numerous grain boundaries synergistically modulate the activation energy between active sites and oxygen-containing intermediates, significantly improving the kinetics of water oxidation.

Electrochemical investigations of decorated graphite felt electrodes with Nafion/TiO2 nanoparticles for vanadium redox flow battery: Improving electro-catalytic characteristics

The present study aimed to investigate the effect of Nafion/TiO2 nanoparticles as an electrocatalyst on the electrochemical behavior of graphite felt (GF) electrodes in a vanadium redox flow battery. Various electrochemical tests, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and linear sweep voltammetry (LSV), were conducted to assess the performance of these electrodes at different concentrations of nanoparticles (2–4 g l-1). Additionally, X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy were employed to analyze the chemical composition, bonding, and morphology of the decorated electrodes, respectively. The CV results revealed several effects of TiO2 nanoparticles on the GF electrode, such as increased peak intensity and shifted peak sites. As the concentration of nanoparticles increased, the peak intensity rose by up to 44%. Moreover, the potentials of the decorated electrodes shifted towards the favorable side compared to the GF electrode, with changes ranging from 18 to 84%. Overall, the optimal concentration of TiO2 nanoparticles (3 g l-1) exhibited excellent electrode performance, characterized by the highest calculated diffusion coefficient, greater reversibility, enhanced electron transfer kinetics, improved stability, lower over-potential, and the lowest activation energy for redox reactions. EIS results demonstrated a significant decrease in polarization resistance (67.2–70.8%) for the decorated electrodes. Furthermore, LSV measurements indicated that the utilization of nano-electrocatalysts effectively inhibited hydrogen evolution at negative potentials.

Tailored electronic properties of PdAu nanocatalysts via one-step electrodeposition for high-performance glucose sensors

The development of efficient and reliable glucose sensors is crucial for the early detection and management of diabetes mellitus. This study introduces a novel one-step electrodeposition method for fabricating bimetallic palladium-gold (PdAu) nanocatalysts directly onto gold electrodes, aimed at enhancing the electrocatalytic performance for non-enzymatic glucose sensing. The one-step electrodeposition technique not only simplifies the fabrication process but also enables precise control over the morphology and electronic properties of the PdAu nanostructures. The optimized electronic interactions between palladium and gold within the nanocatalyst significantly enhance electron transfer kinetics, leading to a high electroactive surface area and improved catalytic activity for glucose oxidation. As a result, the PdAu electrodes demonstrated superior glucose sensing capabilities, with a low detection limit of 83 µM and an impressive sensitivity of 67.2 µA mM-1cm−2 across a linear range of 1–8 mM glucose. The catalyst also exhibited excellent selectivity against common interfering species, as well as remarkable stability and reproducibility over an extended period. These findings underscore the significance of the one-step electrodeposition method in producing bimetallic catalysts with tailored electronic properties, offering a promising approach for advancing electrochemical biosensors in diabetes diagnosis.

Oxygen-Doped Porous Ultrathin Graphitic Carbon Nitride Nanosheets for Photocatalytic Hydrogen Evolution and Rhodamine B Degradation.

Graphite phase carbon nitride (g-C3N4) is a highly promising metal-free photocatalyst, but its low activity, due to limited quantum efficiency and small specific surface area, restricts its practical application. While exfoliating bulk crystals into porous thin-layer nanosheets and incorporating dopants have been shown to improve photocatalytic efficiency, these methods are typically complex, time-consuming, and costly processes. In this study, we developed a simple approach to synthesize oxygen-doped porous g-C3N4 (OCN) nanosheets. The resulting OCN exhibited significantly enhanced light absorption and visible-light photocatalytic activity compared to bulk g-C3N4 (BCN) and g-C3N4 (CN). The OCN achieved an impressive hydrogen evolution reaction (HER) rate of 8.02 mmol g-1 h-1, eight times greater than BCN, and demonstrated a high Rhodamine B (RhB) degradation rate of 97.3 % owing to the generation of abundant singlet oxygen. These improvements in photocatalytic performance are attributed to the narrow band gap and enhanced electron transfer properties, suggesting a promising route for the efficient design of g-C3N4-based photocatalysts.

Potential of Cellulomonas fimi for polysaccharide-fueled microbial fuel cells.

This study examined the feasibility of using Cellulomonas fimi and Shewanella oneidensis as microbial fuel cells fueled by starch, cellulose, chitin, and chitosan. To our knowledge, this is the first report of power generation using C. fimi fueled by these polysaccharides other than cellulose, furthermore the first report of S. oneidensis fueled by chitosan. No differences were observed in the power generation capacities between C. fimi and S. oneidensis when chitin and chitosan were used. However, C. fimi demonstrated effective power generation from starch and cellulose, showing a maximum current density of 17.4mA m-2 for starch and 38.8mA m-2 for cellulose. S. oneidensis could not utilize these fuels to generate electricity. Power generation using C. fimi fueled by starch and cellulose produced acetic acid, lactic acid, and formic acid. However, when chitin and chitosan were used, only acetic acid was produced. These results indicate that electron transfer from C. fimi to the anode may be inefficient. The accumulation of organic acid in the anode solution indicates insufficient electron transfer to the anode. To improve power generation efficiency, it may be necessary to enhance electron transfer from the cells to the anode, for example, by adding a mediator.

Structure-activity relationship between crystal plane and pyrite-driven autotrophic denitrification efficacy: Electron transfer and metagenome-based microbial mechanism

Pyrite-driven autotrophic denitrification (PAD) has been recognized as a promising treatment technology for nitrate removal. Although the occurrence of PAD has been found in recent years, there is a knowledge gap about effects of crystal plane of pyrite on the performance and mechanism of PAD system. Here, this study investigated the effects of crystal planes ({100}, {111} and {210}) of single-crystal pyrite on denitrification performance, electron transfer, and microbial mechanism in PAD system. The removal efficiency of nitrate in B-{210} reached 100%, which was 1.67-fold and 2.86-fold higher than that of B-{100} and B-{111}, respectively. X-ray photoelectron spectroscopy and electrochemical results indicated that Fe-S bonds of pyrite with {210} crystal plane were more susceptible to breakage by Fe3+ oxidation assault, and leaching microbially available Fe2+ and sulfur intermediates to drive autotrophic denitrification. Metagenomic results suggested that community of functional pyrite-driven denitrifiers varied in response to crystal plane, and abundances of N-S transformation and EET-related microbes and genes in B-{210} notably up-regulated compared to B-{100} and B-{111}. In addition, this work proposed a dual-mode for electron transfer pathway during pyrite oxidation and nitrogen transformation in PAD system. In B-{210}, Fe(II)- and sulfur-driven denitrifiers obtained electron after pyrite oxidation-dissolution, and the enrichment of pyrite-oxidizing bacteria in B-{210} could enhance the electron transfer from pyrite through electron shuttles. This work highlighted that stronger surface reactivity and electron shuttle effect in B-{210} enhanced electron transfer, leading to favorable PAD performance in B-{210}. Overall, this study provides novel insights into the structure-activity relationship between the crystal plane structure of pyrite and denitrification activity in PAD system.

Iron-based nitrogen-rich metal-organic framework structure for activation of hydrogen peroxide and peroxymonosulfate for ultra-efficient tetracycline degradation

Fe-based metal–organic frameworks (Fe-MOFs) have been used to catalyze the degradation of organic pollutants; however, the underlying mechanism remains unclear. In this study, we prepared Fe-MOF catalysts featuring a three-dimensional ordered structure and active Fe-N4 coordination centers using self-designed polypyrazole compounds as ligands. Because the coordination centers are similar to the classical single-atom Fe-N4 active neutral structure, Fe-MOFs exhibit excellent performance in activating hydrogen peroxide (H2O2) and peroxymonosulfate (PMS) for the degradation of antibiotics. Moreover, the two adjacent nitrogen atoms in pyrazole strengthen the interaction with active neutral Fe, thereby enhancing the efficiency and selectivity of the catalytic sites. In the presence Fe-MOF/H2O2, a free radical process involving hydroxyl radicals (OH) is activated to achieve a degradation rate of 98.36 % for tetracycline (TC) within 10 min. In a Fe-MOF/PMS system, 97.01 % of TC can be degraded within 10 min through a non-free radical process with singlet oxygen (1O2) as the primary active species. The high degradation efficiency of Fe-MOF is primarily attributed to its highly catalytically active structure, which exerts a van der Waals force effect on the pollutants, thereby facilitating electron transfer between the pollutants and active centers. This shortens the distance between the pollutants and Fe catalytic center, enhances electron transfer, and promotes the chemical adsorption of H2O2 and PMS to form FeN4-H2O2 and FeN4-PMS, respectively. Additionally, the strong coordination within the Fe-N4 pyrazole structure significantly suppresses Fe leaching, facilitating a stable adsorption configuration.

Unveiling the synergistic mechanism of Co-Cu catalysts for efficient oxygen evolution reactions

The development of highly active electrocatalysts for Oxygen Evolution Reactions (OER) is critical in the field of energy conversion and storage. Among potential candidates, diatomic catalysts have demonstrated the potential to outperform monoatomic counterparts, though comprehensive studies on their reaction mechanisms remain limited. In this study, a Co-Cu diatomic catalyst was computationally designed using density functional theory (DFT), and four reaction pathways involving multiple intermediates (*O, *OH, *OOH, *2OH, *O + *OH) were calculated. The results indicate that the Co-Cu diatomic catalyst exhibits superior catalytic performance on pathway II (H2O → *OH → *2OH → *OOH → O2) with an overpotential of 0.27 V, overcoming the limitations imposed by the active site of conventional anion exchange membrane (AEM) catalysts. The high catalytic activity is attributed to the synergistic interaction between the metal atoms, bypassing the high-energy barrier step typically observed in conventional pathways. In this mechanism, the Cu d-band center is close to the Fermi energy level, enhancing electron transfer, while Co provides a stable adsorption site and effectively regulates the adsorption and conversion of reaction intermediates. These findings offer new strategies for the rational synthesis of bimetallic catalysts.

Boosted Hydrogen evolution reaction based on synergistic effect of graphene, MoS2 and RuO2 ternary electrocatalyst

Hydrogen holds the promise of replacing fossil fuels and offers a sustainable pathway for energy generation. However, the large-scale production of hydrogen via the environment friendly electrocatalytic process relies heavily on the performance of electrocatalysts. In this study, we investigate the electrocatalytic performance of graphene nanosheets (GNS), molybdenum disulfide (MoS2), ruthenium dioxide (RuO2), and their composites for hydrogen evolution reaction (HER), a novel combination that has not been explored in previous literature. We synthesize the materials using Liquid Phase Exfoliation at 500 and 1000 RPMs for GNS and MoS2 and via hydrothermal methods for RuO2 nanosheets and nanoparticles, aiming to exploit synergistic effects for enhanced activity and stability. The synthesized GNS-1000/MoS2-1000/RuO2-NSs composite demonstrates promising HER results, showcasing a low overpotential of 63 mV and a reduced Tafel slope of 59 mV/dec. This improvement indicates enhanced electron transfer, improved active site dispersion, and increased surface area due to the synergistic effects, which also aids in long-term electrochemical stability. Our study underlines the potential of GNS/MoS2/RuO2 composites, particularly the GNS-1000/MoS2-1000/RuO2-NSs, in transforming hydrogen production methods and promoting efficient, sustainable energy solutions. The implications of our findings extend the boundaries of materials engineering, edging us closer to a sustainable energy future.

RGO-g-C3N4-Co3O4 Composite Modified Platinum Electrode for Electrochemical Detection of Dopamine

A novel RGO-g-C3N4-Co3O4 composite modified platinum electrode with significant sensing performance for dopamine was fabricated. Herein, RGO-g-C3N4-Co3O4 hybrid nanostructure could boost the electrocatalytic performance of nanoparticles by avoiding the clustering of nanoparticles. These spinel-based composites are stable and affordable materials. Electrochemical impedance spectroscopy revealed enhanced electron transfer at the modified electrode, as evidenced by the lowest charge transfer resistance (Rct) for the RGO-g-C₃N₄-Co₃O₄/Pt electrode. An increased electroactive surface area compared to bare and other modified Pt electrodes was obtained. Several experimental parameters were optimized to maximize sensitivity, including the choice of supporting electrolyte and pH. Cyclic voltammetry conducted at varying scan rates confirmed that the oxidation of dopamine followed a diffusion-controlled process. The modified electrode exhibits outstanding electrocatalytic activity, with a detection limit as low as 8.10 × 10−7 M, demonstrating a wide linear range between 2.00 × 10−6 M to 4 × 10−4 M. Selectivity tests indicated that the sensor could reliably detect dopamine in the presence of common interfering substances such as NaCl, KCl, glucose and urea, ascorbic acid, uric acid and L-dopa. This enhanced sensitivity and selectivity were validated in both synthetic blood and urine samples, providing the electrode’s potential for real-world applications in the diagnosis of neurodegenerative diseases.

Microwave‐assisted control of PtNi nanoalloy clusters on the nitrogen‐doped graphene oxide for energy conversion with oxygen reduction reaction and hydrogen evolution reaction

AbstractResearch on the production and utilization of hydrogen energy is essential to overcome the environmental issues caused by fossil fuels. Herein, we anchor PtNi nanoalloy clusters (Pt‐Ni NACs) on nitrogen‐doped graphene oxide (NrGO) by a facile microwave‐assisted synthesis and analyze the variations of catalyst properties based on the PtNi composition and the presence of nitrogen. Ni inclusion in the Pt matrix can induce lattice strain and change the electronic structure, while the doped nitrogen into the graphene can enhance electron transfer and improve the durability of the catalyst through strong chemical bonding with the alloy clusters. TEM analysis discovers that the NACs are uniformly decorated in a few‐nanometer‐size on the graphene surface, and the formation of the PtNi NACs and structural changes according to composition are confirmed through XRD and XPS. In addition, the structural changes due to N‐doping and its bonding with the NACs are observed through Raman spectroscopy and XPS. Electrochemical measurements reveal that Pt2.6Ni NACs/NrGO exhibits the highest ORR onset potential (0.893 V) and the lowest HER overpotential at 10 mA cm−2 (22 mV) among other catalysts, and those activities are almost unchanged under long‐term durability tests. From these results, Pt2.6Ni NACs/NrGO is utilized in a zinc‐air battery (ZAB) system, demonstrating better battery performance than commercial Pt and Ir‐based catalysts. Moreover, it is applied to hydrogen collection, showing linear trend in hydrogen production over time, confirming the catalyst's availability in hydrogen production and utilization.image