Search Results (96)

We report a galvanic replacement-driven strategy for the in situ growth of highly uniform one-dimensional (1D) Cu@CuO-X (X = Ag, Bi) nanobelts directly on aluminum foils. Unlike conventional multi-step coating or hard-template replication strategies, the formation of these heterostructured nanobelts is governed by a spontaneous interfacial galvanic replacement process between Cu and the introduced metal species, ensuring in situ growth and intimate interfacial integration. Comprehensive SEM, TEM, XRD, and XPS characterizations confirm the successful formation of Cu@CuO-Ag and Cu@CuO-Bi architectures, where Bi predominantly exists in the oxidized Bi³⁺ state, forming Bi₂O₃-like surface species. Benefiting from their 1D anisotropic framework and controllable heterointerfaces, this work underscores the distinctiveness and versatility of the self-templated galvanic replacement strategy for the design of multifunctional nanomaterials. Full article

Tetracycline (TC), a widely used antibiotic, persists in aquatic environments due to its chemical stability, bioaccumulation potential, and role in promoting antimicrobial resistance, posing significant ecological and public health risks. To address the pressing need for effective wastewater treatment technologies, a cobalt nanoparticle-embedded boron nitride nanocomposite (Co/BN) was developed for efficient peroxymonosulfate (PMS) activation. Among the synthesized catalysts, Co/BN-1 exhibited outstanding performance, achieving near-complete TC degradation within 5 min under mild conditions, along with excellent stability and reusability over four consecutive cycles, accompanied by minimal cobalt leaching. Mechanistic studies combining radical scavenging assays and LC-MS analysis revealed the involvement of both radical species (SO₄⁻ and OH) and non-radical pathways (¹O₂), highlighting a synergistic effect between Co nanoparticles and the BN matrix. This work demonstrates the feasibility of Co/BN composites as highly efficient, stable, and eco-friendly catalysts for sulfate radical-based advanced oxidation processes (SR-AOPs), providing a promising strategy for the rapid and sustainable removal of antibiotic pollutants from water systems. Full article

Harnessing ubiquitous mechanical energy for chemical transformations is a grand challenge, primarily impeded by the crystallographic symmetry constraints of conventional piezocatalysts. Here, this long-standing paradigm is shattered by demonstrating potent mechanocatalytic activity in a centrosymmetric material. Synthesized via a facile hydrothermal method, unique SnS nanobelts exhibit a hydrogen evolution rate of 3889 µmol g⁻¹ h⁻¹ under mechanical vibration—achieved without any cocatalysts—a performance substantially surpassing that of most reported piezocatalysts and comparable to state-of-the-art photocatalytic systems. Moreover, the SnS nanobelts were also found to present good cyclic stability. This unprecedented activity was rationalized by the synergy between two effects: sonoluminescence, for which the material’s ideally suited band structure allows efficient photon capture, and flexoelectricity. Furthermore, direct electrical measurements confirmed that SnS generates a flexoelectric current under mechanical deformation, thereby driving the H₂ evolution reaction. These findings not only expand the scope of potential mechanocatalysts by unlocking a vast and previously ignored territory of centrosymmetric materials but also offer valuable guidance and insights for designing high-efficiency, mechanically driven chemical reactions. Full article

The sustainable development of our society faces significant challenges, including the need for environmentally friendly energy storage devices. Our work is concerned with the conversion of Mo-based recycled industrial waste into active nanocatalysts for energy storage applications. To reach this goal, we employed hydrothermal synthesis, a low-cost and temperature-scalable method. The proposed synthesis produces MoO₃ nanobelts (50–200 nm in width and 2–5 µm in length) with a high yield, about 74%. The synthesized nanostructures were characterized in 1 M KOH and 1 M NH₄OH, as alkaline environments are a promising choice for the development of eco-friendly devices. To investigate the material’s behaviour cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) measurements were carried out. From CV curves, it was possible to evaluate the specific capacitance values of 290 and 100 Fg⁻¹ at 5 mVs⁻¹ in 1 M KOH and 1 M NH₄OH, respectively. Also, GCD was employed to evaluate the specific capacitance of the material, resulting in 75 and 60 Fg⁻¹ in 1 M KOH and 1 M NH₄OH, respectively. CV and GCD analyses revealed that MoO₃ nanobelts act as two different types of energy storage devices: supercapacitors and pseudocapacitors. Additionally, EIS allowed us to distinguish between the resistive and capacitive behaviour contributions depending on the electrolyte. Furthermore, it provided a comprehensive electrochemical characterization in different alkaline electrolytes, with the intention of conjugating waste management and sustainable energy storage device production. Full article

To exploit the near-infrared (NIR) light of MoO₃, the MoVO_x mixed oxide was synthesized using a one-pot approach. The effects of different electrodes, V doping, and bias on the optoelectronic properties were investigated. The photoelectric responses to light sources with wavelengths of 405, 532, 650, 780, 808, 980, and 1064 nm were studied using both Au and carbon electrodes with 6B pencil drawings. The results demonstrate that the MoVO_x nanoblets exhibit photocurrent switching characteristics across the broadband region of the light spectrum. Even when zero bias was applied and the mixed oxide sample was stored at room temperature for over two years, a good photoelectric signal was still observed. This demonstrates that the MoVO_x nanoblets present an interface where interfacial charge transfer forms a strong built-in electric field, promoting photogenerated charge separation and transfer while suppressing photogenerated carrier recombination, and exhibiting self-powered characteristics. Interestingly, reducing the power of the typical excitation light sources resulted in a transition from positive to negative photocurrent features. This reflects the result of an imbalance between the concentration of material defects and the concentration of photogenerated electrons. The MoVO_x nanoblets not only enhance charge transport performance, but also significantly improve the exploitation of near-infrared light. Doping with V significantly improves the nanocomposites’ near-infrared (NIR) photoelectric sensitivity. This study demonstrates that heavily doping aliovalent ions during the in situ preparation of nanocomposites effectively enhances their photophysical properties. It provides a straightforward approach to narrowing the band gap of wide-bandgap oxides and effectively avoiding the recombination of photogenerated carriers. Full article

This study investigates the performance of Cu-intercalated V₃O₇·H₂O (CuVOH) as a cathode material for aqueous zinc-ion batteries (AZIBs). Density Functional Theory (DFT) calculations were conducted to explore the effects of Cu²⁺ incorporation and structural water on the electrochemical performance of VOH. The results indicated that Cu²⁺ and structural water enhance Zn²⁺ diffusion by reducing electrostatic resistance and facilitating faster transport. Based on these insights, CuVOH nanobelts were synthesized via a one-step hydrothermal method. The experimental results confirmed the DFT predictions, demonstrating that CuVOH exhibited an initial discharge capacity of 336.1 mAh g⁻¹ at 0.2 A g⁻¹ and maintained a high cycling stability with 98.7% retention after 1000 cycles at 10 A g⁻¹. The incorporation of Cu²⁺ pillars and interlayer water improved the structural stability and Zn²⁺ diffusion, offering enhanced rate performance and long-term cycling stability. The study highlights the effective integration of computational and experimental methods to optimize cathode materials for high-performance AZIBs, providing a promising strategy for the development of stable and efficient energy storage systems. Full article

This work explores the self-assembly and optical properties of a novel chiral, aromatic-rich Boc-Phe-Phe dipeptide derivative functionalized with a benzothiazole bicyclic ring that forms supramolecular structures. Leveraging the well-known self-assembling capabilities of diphenylalanine dipeptides, this modified derivative introduces a heterocyclic benzothiazole unit that significantly enhances the fluorescence of the resulting nanostructures. The derivative’s rich aromatic character drives the formation of supramolecular structures through self-organization mechanisms influenced by quantum confinement. By adjusting the solvent system, the nanostructures exhibit tunable morphologies, ranging from nanospheres to nanobelts. The nonlinear optical properties of these self-assembled structures were studied and an estimated $d_{eff}$ of ~0.9 pm/V was obtained, which is comparable to that reported for the highly aromatic triphenylalanine peptide. Full article

This study reports the development of shape-controlled TiO₂ (B)/anatase heterostructures for the degradation of emerging environmental pollutants, including phenol, methomyl (insecticides), and diclofenac sodium (drug), under UV-visible-light irradiation in ultrapure water and alkaline stormwater. TiO₂ nanobelts were synthesized via a surfactant-free hydrothermal method, yielding structures with widths ranging from 40 to 80 nm and lengths extending up to several micrometers. The synthesized nanobelts were calcined at 400 °C, 600 °C, and 800 °C to form a TiO₂ (B)/anatase heterostructure. For comparison, calcination at 900 °C was also performed, resulting in the formation of pure anatase. The samples calcined at 800 °C (~92% anatase, ~8% nanobelts) exhibited enhanced photocatalytic efficiency, achieving significant total organic carbon (TOC) removal and complete mineralization in both water matrices. These findings contribute to a cost-effective method for developing efficient TiO₂ (B)/anatase heterostructures to avoid rapid charge carrier recombination, with strong potential for advanced wastewater treatment. Full article

This study investigates the enhancement of organic light-emitting diode (OLED) performance through the integration of titanium dioxide (TiO₂) nanocomposites within a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT/PSS) matrix. The nanocomposite films were prepared using a controlled dispersion of TiO₂ belts into the PEDOT/PSS solution, followed by their incorporation into the OLED hole-injection layer (HIL). Our results demonstrate a significant improvement in device efficiency, attributed to the optimized charge carrier mobility and reduced recombination losses, which were achieved by the presence of TiO₂. The nanocomposite hybrid layer enhances light emission efficiency due to its role in modifying surface roughness, promoting better film uniformity, and improving hole injection. The incorporation of TiO₂ nanobelts into PEDOT/PSS led to significant efficiency enhancements, yielding a 39% increase in PE_max, a 37% improvement in CE_max, and a remarkable 72% rise in EQE_max compared to the undoped counterpart. This research provides insight into the potential of TiO₂ nanocomposites in advancing OLED technology for next-generation display and lighting applications. Full article

The triply twisted Möbius carbon nanobelt (TMCNB) possesses an extremely distinctive geometric and electronic structure and therefore is anticipated to demonstrate outstanding optical properties. In this paper, through integrating quantum chemical calculations and wave function analysis approaches, in-depth studies are conducted on the one-photon absorption (OPA) and two-photon absorption (TPA) characteristics, aromaticity, and circular dichroism of the TMCNB. Inspired by this structure, we further deform it to construct a novel structure, MCNB2, and verify the stability of this structure, thereby confirming its rationality. Since variations in structure will result in dissimilar optical properties, we also undertake theoretical analyses on the absorption properties and circular dichroism of MCNB2. The outcomes of this study offer a significant theoretical foundation for the design and construction of chiral optoelectronic materials. Full article

Metal oxide core–shell fibrous nanostructures are promising gas-sensitive materials for the detection of a wide variety of both reducing and oxidizing gases. In these structures, two dissimilar materials with different work functions are brought into contact to form a coaxial heterojunction. The influence of the shell material on the transportation of the electric charge carriers along these structures is still not very well understood. This is due to homo-, hetero- and metal/semiconductor junctions, which make it difficult to investigate the electric charge transfer using direct current methods. However, in order to improve the gas-sensing properties of these complex structures, it is necessary to first establish a good understanding of the electric charge transfer in ambient air. In this article, we present an impedance spectroscopy study of networked SnO₂/Ga₂O₃ core–shell nanobelts in ambient air. Tin dioxide nanobelts were grown directly on interdigitated gold electrodes, using the thermal sublimation method, via the vapor–liquid–solid (VLS) mechanism. Two forms of a gallium oxide shell of varying thickness were prepared via halide vapor-phase epitaxy (HVPE), and the impedance spectra were measured at 189–768 °C. The bulk resistance of the core–shell nanobelts was found to be reduced due to the formation of an electron accumulation layer in the SnO₂ core. At temperatures above 530 °C, the thermal reduction of SnO₂ and the associated decrease in its work function caused electrons to flow from the accumulation layer into the Ga₂O₃ shell, which resulted in an increase in bulk resistance. The junction resistance of said core–shell nanostructures was comparable to that of SnO₂ nanobelts, as both structures are likely connected through existing SnO₂/SnO₂ homojunctions comprising thin amorphous layers. Full article

Porous α-Fe₂O₃ hollow rods/reduced graphene oxide (α-Fe₂O₃ HR/RGO) composites with unique morphological characteristics and a high surface area are prepared through a template strategy, which was systematically studied and found to have outstanding supercapacitive properties. When served as active material in a three-electrode setup, the optimized α-Fe₂O₃ HR/RGO-30, comprised 76.5 wt% α-Fe₂O₃ and 23.2 wt% RGO, was able to offer the largest specific capacitance of 426.3 F g⁻¹, an excellent rate capability as well as satisfactory cycle life with capacitance retention of 87.7% and Coulombic efficiency of 98.9% after continuously charging/discharging at 10 A g⁻¹ for beyond 10,000 cycles. Such electrochemical behaviors of the α-Fe₂O₃ HR/RGO-30 electrode can rival or even surpass those of many Fe₂O₃-based electrodes documented in the previous literature. Later, a symmetric supercapacitor cell of α-Fe₂O₃ HR/RGO-30//α-Fe₂O₃ HR/RGO-30 was fabricated. The assembled device offers the maximum energy density of 18.7 Wh kg⁻¹, and also exhibits commendable rate capability, and features stable cycling durability (with capacitance retention of 83.2% together with a Coulombic efficiency of 99.3% after 10,000-cycle charge/discharge at 5 A g⁻¹). These notable electrochemical performances enable the α-Fe₂O₃ HR/RGO-30 composite to be a high-potential material for advanced energy storage systems. Full article

In this work, we synthesized a new composite material comprised of previously formulated resveratrol nanobelt-like particles (ResNPs) and selenium nanoparticles (SeNPs), namely ResSeNPs. Characterization was provided by FESEM and optical microscopy, as well as by UV-Vis and FTIR spectroscopy, the last showing hydrogen bonds between ResNPs and SeNPs. DPPH, TBA, and FRAP assays showed excellent antioxidative abilities with ResNPs and SeNPs contributing mainly to lipid peroxidation inhibition and reducing/scavenging activity, respectively. The antibacterial effect against common medicinal implant colonizers pointed to notably higher activity against Staphylococcus isolates (minimal inhibitory concentrations 0.75–1.5%) compared to tested gram-negative species (Escherichia coli and Pseudomonas aeruginosa). Antibiofilm activity against S. aureus, S. epidermidis, and P. aeruginosa determined in a crystal violet assay was promising (up to 69%), but monitoring of selected biofilm-related gene expression (pelA and algD) indicated the necessity of the involvement of a larger number of genes in the analysis in order to further establish the underlying mechanism. Although biocompatibility screening showed some cytotoxicity and genotoxicity in MTT and alkaline comet assays, respectively, it is important to note that active antioxidative and antibacterial/antibiofilm concentrations were non-cytotoxic and non-genotoxic in normal MRC-5 cells. These results encourage further composite improvements and investigation in order to adapt it for specific biomedical purposes. Full article

Field-effect transistor (FET)-based biosensors are powerful analytical tools for detecting trace-specific biomolecules in diverse sample matrices, especially in the realms of pandemics and infectious diseases. The primary concern in applying these biosensors is their stability, a factor directly impacting the accuracy and reliability of sensing over extended durations. The risk of biosensor degradation is substantial, potentially jeopardizing the sensitivity and selectivity and leading to inaccurate readings, including the possibility of false positives or negatives. This paper delves into the documented degradation of silicon nanobelt FET (NBFET) biosensors induced by buffer solutions. The results highlight a positive correlation between immersion time and the threshold voltage of NBFET devices. Secondary ion mass spectrometry analysis demonstrates a gradual increase in sodium and potassium ion concentrations within the silicon as immersion days progress. This outcome is ascribed to the nanobelt’s exposure to the buffer solution during the biosensing period, enabling ion penetration from the buffer into the silicon. This study emphasizes the critical need to address buffer-solution-induced degradation to ensure the long-term stability and performance of FET-based biosensors in practical applications. Full article