Single-walled carbon nanotubes (SWCNTs) are a unique material. The properties of SWCNTs can be modified with covalent and noncovalent functionalization, the substitution of carbon atoms in the SWCNT walls, intercalation, and filling. Filling the SWCNTs can lead to novel materials with modified properties. In this work, we filled the SWCNTs with cobalt chloride and investigated the filled material using different methods to reveal the modification of the electronic properties. First, we investigated the filled SWCNTs with optical absorption spectroscopy (OAS). In the OAS spectra, the characteristic peak of optical transitions between the first van Hove singularities of the semiconducting SWCNTs was suppressed. This corresponded to the Fermi level shift of the SWCNTs. Second, we applied Raman spectroscopy to the cobalt chloride-filled SWCNTs to investigate the changes in the Raman modes of the filled SWCNTs. In the radial breathing mode, shifts in the peaks of D-, G-, and 2D-bands of the cobalt chloride-filled SWCNTs were observed. With three laser wavelengths, the changes in the properties of the semiconducting and metallic-filled SWCNTs were analyzed. The doping of the SWCNTs was subsequently detected. Third, near-edge X-ray absorption fine-structure spectroscopy was applied to reveal and prove the chemical bonding in the cobalt chloride-filled SWCNTs. Fourth, the C 1s X-ray photoelectron spectra of the cobalt chloride-filled SWCNTs were analyzed. The spectra of the filled SWCNTs demonstrated shifts and broadening, which confirmed the p-doping of the SWCNTs. Therefore, all four methods proved the variations in the electronic properties of the cobalt chloride-filled SWCNTs. These results are needed for nanoelectronic applications.

Silicon dioxide (SiO2) has emerged as a highly promising material that is currently under extensive investigation due to its remarkable capability to facilitate the generation of nanostructures, which are of significant interest in various scientific and technological applications [1]. In order to effectively conduct molecular dynamics simulations that involve the intricate properties and behaviors of SiO₂, it is imperative to accurately fit the potentials that characterize this particular material. However, it is regrettably the case that the existing literature provides limited information concerning the parameters A + R of SiO₂ when utilizing the DL_POLY simulation code [2]. Consequently, this limitation necessitated the development of our own set of potentials specifically tailored for these materials. To successfully achieve this objective, a total of nine pairs of parameters are generally required, yet it is noteworthy that the interatomic pair parameters for the oxygen–oxygen (O-O) interactions had already been fitted based on the established TiO2 potentials, which allowed us to focus on fitting only six pairs of parameters instead. More specifically, we concentrated our efforts on the short-range parameters, which include the values of {A_ij, ρ_ij, and C_ij} associated with each of the two distinct atomic pair interactions, namely Si-Si and Si-O. The reference crystal structure that served as the basis for our investigation of SiO₂ is the tetragonal stishovite structure, which is characterized by the space group notation p42/mnm. We sourced the necessary values for the elastic constants, lattice constant, bulk modulus, and static dielectric constant from a reputable study conducted by Cem Sevik and Ceyhun [3], while the cell parameters were obtained through the use of the MedeA software platform. It is worth mentioning that the process of manually adjusting the values of Aij, ρij, and Cij using the GULP program [3] poses significant challenges, making it a complex task to derive.

Technology has taken a strategic role in the livelihoods of many due to advancing ways of life, such as small-device-controlled gadgets, access points and home appliances. This requires a reliable energy supply and a sustainable energy storage in order to function. Energy storage devices have become the newest technology in the spotlight due to the demand for small, reliable and long-life electronic gadgets. Lithium-ion batteries (LIBs), when used as storage devices, have never performed to expectation; thus, they leave room for improvement. Manipulating one or two of the components of LIBs could result in improved storage capabilities. Most LIBs use graphite as their anode material with properties somehow lacking due to lower conductivity, side reactions, wear and tear, and oxidising at high temperatures. This study compares various biomass feedstocks for potential application in lithium-ion batteries for energy storage enhancement. Biomass feedstocks are processed through pyrolysis, and the resulting product is analysed for graphite-like properties. Very high temperatures are used, and the obtained products are then activated using KOH for high levels of graphitisation. SEM, XRD, and FTIR results suggest a very rich area of study that is open to be explored, with improved structural properties observed. Physical observations indicate indistinguishable characteristics and potentially superior properties with plant-based biomass feedstocks. Mass differences indicate that a large amount of feedstock is required; eventually, the pollution satisfying set from the sustainable development goals is reduced. As graphite is insoluble in water and other liquids such as ethanol, the obtained materials have same property.

Nanoparticles have gained significant attention as a cost-effective and robust alternative to natural enzymes. Their stability makes them suitable for a wide range of applications in medicine, science, and industry. Horseradish peroxidase (HRP) plays vital roles in biological systems by catalyzing substrate oxidation in the presence of hydrogen peroxide (H₂O₂). However, HRP is affected by harsh conditions of pH and temperature. In this work, carbon dots doped with metals (X-CDs) are utilized as nanozymes, mimicking the function of horseradish peroxidase (HRP) to some extent. Cobalt (Co), Nickel (Ni), Iron (Fe), and Copper (Cu) are used as the carbon dot-doping materials. X-CDs are synthesized from inexpensive chemicals in just a few steps, saving time and costs and showing better robustness. A total of 0.25 m mole of metal acetate was mixed with 87 mg L-Arginine, 80.6 µL Amine, and 100 µL distilled water at 240°C, for 3 minutes, and was then purified by a 0.5-1 kDa MWCO membrane against 1 liter of distilled water for five days. The peroxidase- like activity of the nanozymes was investigated by measuring the absorbance of TMB solution at 652 nm in the presence of H₂O₂. The results showed that X-CDs had a maximum ability to catalyze TMB in acidic buffer media at pH=4. High temperatures did not destroy the internal system of the X-CDs. Also, the X-CDs did not lose their activity after 3 months of storage at 4 C. To conclude, nanozymes exhibit evident peroxidase activity, which in some ways can be compared to the activity of horseradish peroxidase (HRP), with excellent stability at harsh pH and high temperature. They maintain their activity even after months, and they do not need to be stored at low temperature, nor do they need stabilizers. These features can be employed in biosensing by conjugating nanozymes to antibodies, where they appear in color as a sign of their presence.

Agricultural disease control faces serious hurdles due to the increasing resistance of pathogens and the banning of synthetic plant protection products (PPPs), resulting in environmental and public health risks. In this context, biodegradable nanocarriers derived from macroalgae (Bio-MACs), such as functional polysaccharides and proteins (e.g., alginic acids, chitosans, and carrageenans), offer promising technical solutions. The efficient encapsulation and controlled release of bioactive metabolites with antifungal, antibacterial, and biostimulant properties can be achieved using these nanocarriers. The developed systems protect the active ingredients from degradation, prolong their efficacy in soil, and minimize soil and water contamination by reducing application doses by up to 40%. Furthermore, these systems exhibit low toxicity to non-target organisms, such as Daphnia magna and Eisenia fetida, in accordance with the OECD TG 202 and 207 guidelines. Bio-MACs have regulatory advantages over synthetic nanoparticles because they are generally recognized as safe (GRAS), non-toxic, non-reactogenic, widely available and highly biodegradable. These characteristics make them uniquely suited for use in the food and agricultural industries, where sustainability is critical. Moreover, the economic potential and marketability of Bio-MACs are booming, particularly given the rising demand for eco-friendly agricultural inputs and the rapid expansion of the biopesticides sector, which is set to hit USD 10 billion by 2027. However, successful market integration requires acknowledging and addressing challenges such as public and regulatory concerns surrounding nanotechnology. This requires standardizing production protocols and conducting large-scale field trials to demonstrate the effectiveness and safety of nanotechnology. Thus, the objective of this systematic review is to explore the potential of Bio-MACs for encapsulating and releasing biological metabolite activities.

Metal–organic frameworks (MOFs) with strong metal–ligand interaction are acceptable as a coordination polymer. They are porous and crystalline materials. Besides that, their surface area and pore volume can increase to 5900 m²/g and 2 cm³/g. MOFs have many topologies and pore sizes, and over 100,000 types of MOFs have been discovered up until now. There are a wide variety of application areas of MOFs. They have been used in catalysis, biomedical applications, chemical sensing, gas separation, and storage. Determining the topological features is important in revealing the porosity and mechanical properties of MOFs. It is also known that improving crystallinity paves the way for an increase in the porosity and surface area of MOFs. Hence, this study aimed to unveil the crystallographic features of some popular MOF types such as ZIF-8, ZIF-67, and UiO-66. The crystal data, bond length and angles, and crystal structure of the selected MOFs were identified by using ToposPro software. Besides that, some simplifications to the topology of the MOFs were made by utilizing ToposPro. Simplification included removing hydrogen atoms from the structure. Thus, a clear version of the structure was obtained. The crystallographic data observed with ToposPro was compared to data found in the Cambridge Structural Database (CSD). ToposPro is a new topology tool, so research is scarce on this topic for MOFs.

Introduction: Carbon dots (C-dots) are biocompatible, photoluminescent nanoparticles composed mainly of carbon, hydrogen and oxygen. They can be synthesized via pyrolytic decomposition of various precursors, including polymers, small organic molecules and biomass waste (1,2). Their chemical composition, size, shape and macroscopic properties are largely impacted by reaction parameters such as temperature, precursor concentration and duration.

Methods: C-dots were derived via pyrolytic treatment of citric acid and urea and were purified via dialysis, centrifugation and filtration before being subjected to post-synthesis hypochlorite treatment (3,4). They were characterized using a combination of spectroscopic and microscopic techniques such as TEM, XRD, FTIR and XPS. Their photoluminescent properties, cytotoxicity and antimicrobial activity were systematically evaluated.

Results: We demonstrate that varying the molar ratio of precursors and applying standard size-separation methods yields materials with strong photoluminescence in both liquid and solid states as well as advanced antimicrobial properties. The direct NaClO treatment of C-dots causes significant surface oxidation and etching, which is a process that reduces UV-vis absorbance, increases the quantum yield sixfold and greatly enhances antifungal activity.

Conclusion: We present a low-cost, time-efficient strategy to generate a range of highly photoluminescent materials based on C-dots. The resulting materials are promising candidates for various applications, including bioimaging, biosensing, antimicrobial treatment, environmental sensing and remediation, forensic science and optoelectronics.

References

1. A. Kelarakis, Current Opinion in Colloid and Interface Science 2015, 20, 354
2. A. Kelarakis MRS Energy and Sustainability, 2014, 1, E2
3. J.D. Stachowska, A. Murphy, C. Mellor, D. Fernandes, E. Gibbons, M. Krysmann, A. Kelarakis, E. Burgaz, J. Moore and S. G. Yeates, Scientific Reports, 2021, 11,10554
4. S. Gavalas, S. Beg, E. Gibbons, A. Kelarakis, Nanomaterials 2025, 15, 184

Green chemistry methods have clearly revealed the definite demands for chemical procedures in performing ecofriendly synthesis using so-called biogenic compounds (BGCs) extracted from biological resources, such as fungi, algae and plantae. These compounds can potentially be used as reducing and stabilizing agents in nanoparticle (NP) synthesis. Modern research in the field of NP synthesis increasingly goes beyond traditional thermodynamic and kinetic approaches. More complex interactions are considered, which are organized according to the analog principle in the environment where nanoparticles with a given morphology are formed. The media state where chemical reactions occur could be viewed as manifestations of specific conformational BGC changes, which influence NP formation with its defined morphology. In this work, the reaction media is considered not only as a chemical system but also as a kind of analog processing unit, where pH, temperature, and spectra (the environment parameters) are the input data, while the size and shape of the nanoparticles formed (the morphology parameters) are the output data. The presented approach allows us to focus on information structure analysis, where each media state transition is associated with a change in the BGC conformational structure which, in turn, affects the size and shape of the NP formed.

Introduction

Chalcogens elements like Selenium (Se) and Tellurium (Te) have garnered significant interest within the scientific community due to their multidisciplinary applications in opto-electronic, bio-medicine and energy devices. Indeed, both (Se and Te) have been identified as energy-critical elements by the American Chemical Society and Materials Research Society. They both are rare earth elements that possess the same crystal structure with a chiral nature. When both of them are mixed, they easily form a totally miscible binary alloy, giving rise to unique properties like a tunable bandgap, stability, and high mobility, demonstrating their potential for use in high-performance opto-electronic devices. In this report, SeTe nanorods were synthesized for the first time by using the "bottom-ablation" Pulsed Laser Ablation in Liquids (PLALs) technique. PLALs is acost-effective and green technique that is used to produce nanoparticles with high purity in comparison to wet chemistry methods. Additionally, PLALs also helps to generate nanostructures with desirable phases, shapes and sizes.

Method

Bulk Selenium–Tellurium (SeTe) targets (99.999% purity) were immersed in a 50 ml single-neck glass flask containing 10 ml of acetone. The SeTe targets were irradiated for 5-minutes using a Nd:YAG laser, emitting at 1064 nm and pulsing at 1 kHz. The average laser power was 12.5 W, with an energy of 12.5 mJ/pulse at 1 kHz. The average beam spot size was measured to be around ~ 110 ± 28 μm, delivering a fluence of around ~131 ± 33 Jcm^-2.

Results

Finally, after 5 minutes of irradiation, monodispersed hexagonal-shaped TeSe nanorods were produced. The crystal structure of those nanorods is hexagonal. The bandgap was measured to be around ~ 2 eV.

Conclusions

Here, we reported the synthesis of the TeSe nanorod for the first time using the PLAL technique. Those synthesized rods were characterized by Scanning Electron Microscopy, X-ray Diffraction, and Raman and Photoluminescence Spectroscopy. Those rods will hold great potential for advancing the development of high-performance solar cells and photodetectors.

Bismuth antimonide (BiSb), a narrow-bandgap semiconductor, has attracted considerable interest for quantum applications due to its remarkable band structure and unique electronic properties. Composed of group V semimetals Bismuth (Bi) and Antimony (Sb), this miscible binary alloy forms a fully solid solution throughout the entire composition range. This material exhibits insulating behavior in its bulk and displays conducting surface states, making it the first experimentally observed 3D topological insulator. The alloy’s composition plays a crucial role in shaping its electronic band structure. Indeed, Bi_1-xSb_x undergoes a series of changes in its electronic structure as the Sb concentration increases: transitioning from a semimetal to an indirect bandgap semiconductor, followed by a direct bandgap semiconductor, then back to an indirect bandgap, and finally to a semimetal.

A BiSb target in pellet form (99.99% purity, from Sigma-Aldrich), cleaned with acetone, was placed at the bottom of a 50 mL single-neck round-bottom flask and submerged in 10 mL of acetone. Bottom ablation was carried out using a Q-switched Nd: YAG laser from Electro Scientific Industries operating at 1064 nm with a repetition rate of 1 kHz for 5 minutes. Morphological and structural properties were analyzed using HRTEM, EDX, Raman, XRD, UV-Vis, zeta potential, and DLS.

The size of the QDs was centered around 9 ± 2 nm and was spherical in shape. The bandgap was measured to be around 2.02 ± 0.27 eV, which is significantly higher than the bulk value. Strong evidence of quantum confinement was observed, as indicated by the peak shift in the Raman spectrum.

BiSb quantum dots were successfully synthesized for the first time using the PLAL technique. The QDs exhibited a spherical shape with a size of around 9 ± 2 nm and a significantly increased bandgap of approximately 2.02 eV, indicating strong quantum confinement effects. These results highlight the potential of BiSb QDs for quantum and optoelectronics applications.