ChemNanoMat最新文献

The oxygen evolution reaction (OER) is the rate-limiting step in overall water splitting for hydrogen production. Transition metal hydroxides have emerged as the most promising candidate for efficient OER. In this study, polydopamine coordination and nitridation strategy is combined to obtain a series of bimetallic catalysts including FeCoN/NF, FeNiN/NF, FeCuN/NF, and CoCuN/NF. Competitive OER activities are achieved with the low overpotentials of 223/268 mV at the current density of 10/100 mA cm⁻² in the FeCoN/NF catalyst with a good stability. The OER mechanism is further explored via the introduction of molecular probe of tetramethylammonium cation in the electrolyte and methanol oxidation reaction. The results indicate that the excellent OER activities of the catalysts are achieved through the lattice oxygen oxidation mechanism pathway. Moreover, hydrogen evolution reaction activities of the catalysts are evaluated and the low overpotentials of 302/393 mV at the current density of 10/100 mA cm⁻² are achieved in the FeCoN/NF catalyst, suggesting great potential of catalysts in the overall water splitting.

Photocatalysis is emerging as a sustainable technique for green hydrogen production, where optimization of reaction parameters along with material engineering plays a crucial role. Herein, a systematic study on the role of various reaction parameters affecting photocatalytic hydrogen evolution has been explored using Degussa P25 as the model catalyst under both particulate and thin film mode. The effect of various reaction parameters, such as catalyst loading, scavenger loading, co-catalyst loading, and temperature on photocatalytic hydrogen evolution is studied under different modes, such as stirring, sonication, and thin film. The studies reveal that the optimization of the above reaction parameters can improve the photocatalytic hydrogen production performance significantly in all the irradiation conditions and reaction modes. Sonication-assisted photocatalytic hydrogen evolution could enhance the optimal catalyst loading, co-catalyst loading, leading to superior hydrogen evolution. Further, the optimized thin-film configuration could achieve a hydrogen evolution rate of 0.19 mol g⁻¹ h⁻¹, over 4 h at 40 °C under solar irradiation which is nearly 3 times over the reported value of Degussa P25 in particulate mode and 2.5 times improvement in thin film mode over optimized particulate mode. These findings highlight the critical role of reaction parameter optimization in achieving enhanced hydrogen evolution efficiency.

The COVID-19 pandemic highlights the urgent need for rapid, accessible, and cost-effective diagnostic technologies. Traditional diagnostic methods, although effective, often require high-cost equipment and lengthy processing times. Herein, the development of an electrochemical immunosensor based on fluorine-doped tin oxide (FTO) electrodes modified with zinc oxide nanorods (ZnONRs) for detecting the receptor-binding domain (RBD) of SARS-CoV-2 in saliva is presented. ZnONRs offer a favorable platform due to their large surface area, low production cost, and efficient electron transport properties. To improve selectivity and sensitivity, ZnONRs are functionalized with monoclonal antibodies (mAbs) conjugated to gold nanoparticles (AuNPs). Four murine anti-RBD mAbs (2B9F9, 3E5G8, 4B1D3, and 4H4A2) are evaluated by ELISA and electrochemical methods. While all mAbs demonstrate recognition of the RBD in ELISA, only the 4B1D3 mAb produces a measurable electrochemical signal, achieving a detection limit of 1.7 μg mL⁻¹ and exhibiting recognition of both the original Wuhan-Hu-1 strain and the Omicron variant. The immunosensor demonstrates excellent performance in tests with real human saliva samples, reinforcing its potential as a noninvasive, rapid, and scalable platform for point-of-care viral diagnostics.

With the increasing demand for high-performance lithium-ion batteries, carbon nanotubes and graphene have emerged as key conductive additives driving technological advancements in this field. Compared to traditional carbon black, these materials exhibit superior electrical conductivity, excellent mechanical flexibility, and unique dimensional advantages, demonstrating significant potential in constructing efficient 3D conductive networks and markedly enhancing the kinetics of electron and ion transport within electrodes. This review comprehensively explores their dimension-dependent properties, synergistic effects in composite systems, and specific applications alongside performance optimization mechanisms in various electrode systems such as lithium iron phosphate, nickel-cobalt-manganese cathodes, and silicon-based anodes. Key challenges including dispersion homogeneity and long-term structural stability of the conductive networks are critically examined. Furthermore, future development pathways for scalable fabrication strategies are outlined.

Effective pulmonary drug delivery necessitates synergistic integration of functional carriers with optimized administration routes. Notably, inhalation administration of artificial cell-derived vesicles (ACDVs) has emerged as a compelling therapeutic paradigm. However, while ACDVs leverage cell-inherent bio-functionality for lung cancer targeting, their lipid-protein fragility under nebulization shear stress causes structural collapse and drug leakage. To address this challenge, a lipid fusion strategy, engineering lipid-hybridized nanovesicles (LNVs) is developed through coextrusion of ACDVs with liposomes (LIPs), creating composite membranes with cholesterol-enhanced ordering. LNVs are verified to exhibit the homogeneous lipid-protein integration while preserving parental membrane proteomics. Clinically relevant nebulization (vibrating mesh/jet) assessments demonstrated LNVs’ superior stability: minimal hydrodynamic diameter variation (<10 nm vs. > 50 nm for ACDVs) and controlled polydispersity at low lipid ratios, addressing particle aggregation. Notably, LNVs retained 87% tumor-targeting efficiency postnebulization, demonstrating comparable performance to nonnebulization ACDVs. Furthermore, they maintained >90% cell viability across lung cell lines BEAS-2B and exhibited excellent bio-compatibility. This stabilization strategy preserved critical bio-functionality and reinforced biological vesicles against nebulization instability without additional sophisticated surface modifications. The simplicity and scalability of such methodology highlight transformative potential for pulmonary delivery of complex biologics.

The electrochemical conversion of CO₂ into valuable chemical fuels offers a promising approach to addressing environmental and energy challenges. However, catalysts used in the electrochemical CO₂ reduction reaction (eCO₂RR) often undergo structural evolution under operational conditions, leading to uncertainties regarding active sites and reaction mechanisms. Real-time monitoring of catalytic surfaces and intermediates is therefore crucial. Among various characterization techniques, in situ Fourier-transform infrared spectroscopy (FTIR) provides unique molecular-level insights into surface-bound species, reaction pathways, and catalyst-electrolyte interactions. This review highlights recent advancements in in situ FTIR applications for eCO₂RR, emphasizing its role in identifying active sites, materials interfaces, and transient intermediates. Additionally, methodological challenges are discussed, particularly the need for continuous-flow electrolyzers for in situ studies, and outline future research directions to improve real-time catalyst monitoring, advance mechanistic understanding, and enhance industrial scalability.

The synthesis of metal-free electrocatalysts for oxygen reduction reaction (ORR) in fuel cells has attracted remarkable attention. We report the synthesis of B, N, and BN co-doped carbon materials by the hydrothermal method. The effect of surface oxygen on graphene oxide over the amount of N and B doping was investigated. Two types of carbon were evaluated: 1) commercial graphene oxide (GO_comm) and 2) GO chemically modified. GO exhibited higher surface oxygen (27.16%) and structural defects (I_D/I_G = 0.97) after chemical modification, which favors the amount of heteroatom doping. The N-doped carbon (N-GO and N-GO_comm) showed a higher onset potential (E_onset) than B-doped carbon samples (B-GO and B-GO_comm), which can be associated with the higher amount of N-doping, N electronegativity, and N-species obtained. The BN co-doped GO showed a synergetic effect, increasing the limited and kinetic current density, and the number of electrons transferred closer to four (n = 3.9 e-). The presence of both N (pyridinic/quaternary) and B (BC₃) heteroatoms increased the activity of B-N-GO for the ORR, showing a higher current density in both kinetic and mass transfer regions. This work provides new alternatives of an attractive electrocatalyst (B-N-GO) for ORR application.

A sensitive electrochemical immunosensor is developed for detecting insulin antibodies, predictive biomarkers of early type 1 diabetes in genetically predisposed individuals. The sensor is prepared by immobilizing chromone-indole-pyrazole cobalt nanoparticles (CIP-CoNPs) onto a platinum electrode, followed by insulin antigen attachment and surface blocking with bovine serum albumin. The CIP ligand, with its electron-rich π-system and strong coordination sites, enhances electron transfer, nanoparticle stability, and biomolecule immobilization, boosting sensitivity and selectivity. The nanoparticles are synthesized via a green route using lemon peel extract, increasing surface area and electrochemical conductivity. Scanning electron microscopy confirms a spherical morphology. Fabrication steps are characterized using cyclic voltammetry and electrochemical impedance spectroscopy, linking the nanocomposite structure to changes in electrochemical properties during sensor assembly. Under optimized conditions, square wave voltammetry detects insulin antibodies over a linear range of 0.001–50 ng mL⁻¹. The sensor achieves a detection limit of 0.34 ng mL⁻¹ and a sensitivity of 5.60 μA ng mL⁻¹. It shows excellent reproducibility and accuracy in synthetic human serum, with recoveries of 98.7–101.3% and relative standard deviations of 1.19–2.34%, confirming strong potential for clinical application.

The alarming increase in pharmaceutical contaminants and toxic dyes in aquatic environments necessitates the development of innovative and sustainable remediation strategies. This study presents a circular economy-driven method to synthesize nanocrystalline ZnMn₂O₄ photocatalysts from spent zinc–carbon batteries for the degradation of ciprofloxacin, a widely used broad-spectrum antibiotic. The ZnO (from the anode) and MnO₂ (from the cathode) are recovered and used as precursors in the solid-state synthesis of ZnMn₂O₄ via thermal treatment. Characterizations by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy confirm the formation of a crystalline spinel structure with uniform elemental distribution. The synthesized ZnMn₂O₄ exhibits strong visible-light absorption with a narrow bandgap of 1.94 eV and high photocatalytic efficiency in degrading ciprofloxacin, with a 71% degradation. The material displays excellent stability, reusability, and degradation kinetics, making it suitable for real-world applications. This work not only provides a sustainable method for valorizing battery waste but also offers a low-cost, environmentally friendly photocatalyst for wastewater processing, following green chemistry guidelines and the circular economy.

Understanding the synergy of different fundamental components of a rechargeable aqueous battery is quite pivotal for making technological advances. Herein, the aqueous electrolyte-enabled electrochemical K⁺ ion storage in Bi₅Nb₃O₁₅ is illustrated for the first time. While achieving a satisfactory electrochemical cycling stability remains a bottleneck, it is shown that a favorable electrochemical interface between the electrode material and current collector can alleviate this issue. The crucial role of this active-inactive interface is unveiled using electrochemical impedance spectroscopy, electron microscopy, corrosion, and contact angle measurements. It reveals that the interface resistance plays a significant role in the achievement of long-term cycling stability. Graphitic substrate shows least corrosion rate among the others, whereas it has the highest polarization resistance. A stable capacity above 100 mAh g⁻¹ is achieved with the graphite current collector, whereas the other substrates, such as Ti, Ni, and stainless steel, are not beneficial. The wettability of the interface is also found to be crucial in the ion insertion phenomena. This work definitely serves as a pertinent guide to wring out the best of an electrode material in attaining high energy K⁺-ion aqueous batteries.