Nano Hybrids and Composites Vol. 48

Abstract: In this study, nanocrystalline ZnO-TiO2 hybrid metal oxide was successfully synthesized using a low-temperature hydrothermal method at 90 °C for 24 hours. Zinc nitrate hexahydrate, titanium (IV) oxide, and sodium hydroxide were employed as reactants without any additives. The synthesized ZnO-TiO2 hybrid nanomaterial was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanningelectron microscopy (FE-SEM), and Energy dispersive X-ray spectroscopy (EDAX). XRD results confirmed the presence of hexagonal zincite (ZnO) and rutile (TiO2) phases, with crystallite sizes of 60.28 nm and 48.12 nm, respectively. FT-IR analysis identified metal-oxide stretching vibrations, while FESEM revealed a granular and rod-like morphology, consistent with XRD results. EDAX confirmed the elemental purity of the hybrid metaloxide, detecting only Zn, Ti, and O elements. Due to its high crystallinity and controlled morphology, the ZnO-TiO2 hybrid nanomaterial has potential applications in gas sensing, environmental remediation, and energy-related fields.

Abstract: In contrast to bulk materials, nanoparticles, which are distinguished by their extremely small size and remarkable surface area-to-volume ratio, have unique physical and chemical properties. Among the several metal-oxide nanoparticles, green zinc oxide nanoparticles have drawn a lot of interest because of their wide range of uses, including antibacterial, antifungal, antimicrobial, and anticancer activities. To assess the potential of zinc oxide nanoparticles in developing domains like bioapplications, this thorough investigation offers insights into the shape and structure of ZnO NPs as well as their characteristics and attributes using characterisation procedures. This work is novel because it carefully examines various synthesis techniques for zinc oxide nanoparticles, provides a thorough understanding of their chemical and biological complexities, and investigates how these nanoparticles' special properties can revolutionise this field. Through this investigation, we want to clarify the complexities of synthesis while also illuminating the wide range of uses and constraints of zinc oxide nanoparticles, offering a path forward for further nanotechnology research and development.

Abstract: Chemical synthesis of nanocomposite particles based on titanium dioxide modified with iron and gold was carried out. It was shown that, depending on the mass content of the doping species, the phase transformation of titanium hydroxide at T = 700 °C proceeds with the formation of either anatase (2 wt.%) or anatase and rutile (8 wt.%). The doping species form a hematite phase and gold clusters on the metal-oxide surface. A weakly crystalline anatase obtained by the transformation of metatitanic acid (MTA), with a particle size of 8 nm and a sulfur content of 0.036%, was selected as the co-catalyst. The anatase co-catalyst exhibits photocatalytic activity in the destruction of organic dyes. Its introduction into the TiO₂&Fe₂O₃&Au nanocomposite suspension promotes the catalytic degradation of cationic and anionic dyes at temperatures ranging from 35 to 60 °C. It was observed that the degradation degree of the solutions after 150 min of catalytic process is the following: Methyl Orange (MO) – 72 %, Methylene Blue (MB) – 71.5 %, Rhodamine B (RhB) – 63.5 %, and Orange G (OG) – 47 %. The reaction rate constant depends on the composition of the dye, varying from 6.5·10^-4 min^-1 for OG to 2.56·10^-3 min^-1 for MB. The prospect of creating heterostructures based on TiO₂ modified with hematite and gold, and their further adaptation for photocatalytic hydrogen production, is considered.

Abstract: Thermoelectric materials are valued for their ability to convert waste heat into electrical energy. Antimonene nanosheets (AnNS) have recently emerged as a promising thermoelectric material due to their unique two-dimensional structure. However, developing efficient and scalable methods for preparing AnNS-based thermoelectric composites with improved performance remains challenging. In this study, we developed an efficient and environmentally friendly method for preparing antimonene nanosheet (AnNS)/graphene platelets (GNPs) composites using ultrasonic dispersion in an ethanol-based system, followed by thin film fabrication via cold-pressing. Atomic Force Microscopy (AFM) was used to characterize the microstructure and thickness of the nanosheets, while Scanning Electron Microscopy (SEM) images revealed the contact structures at different GNP concentrations. The characterization of the thermoelectric composites involved techniques such as X-ray diffraction (XRD) and Raman spectroscopy. The thermoelectric (TE) performance of the composites was systematically evaluated across different GNP volume fractions. Composites containing 1 vol% GNPs exhibited the highest electrical conductivity, measured at 2158.22 ± 25.5 S/cm, along with a Seebeck coefficient of 27.17 ± 0.15 µV/K, yielding a power factor of 159.34 ± 5.6 µW/m·K². When these composite films were integrated into a thermoelectric generator (TEG) and exposed to a human body temperature gradient of 11 °C, they produced a continuous voltage of 43.62 mV and a current of 0.21925 µA, yielding an output power of 9.56 nW. Additionally, the corrosion resistance of the composites was assessed, revealing that the 1 vol% GNPs composite exhibited superior performance compared to other compositions.

Abstract: Elemi essential oil, extracted from the resin of the elemi tree (Canarium luzonicum), is highly valued for its distinctive aromatic and medicinal properties. Its complex composition includes various monoterpenes and sesquiterpenes such as α-phellandrene, limonene, and elemicin, which collectively contribute to its unique fragrance and therapeutic benefits. However, the oil’s susceptibility to environmental factors such as heat, light, and oxidation often leads to degradation and reduced efficacy. In this study, we investigated the encapsulation of elemi essential oil components within cyclodextrin metal-organic frameworks (CD-MOFs) using molecular docking and molecular dynamics (MD) simulations to assess adsorption behavior and complex stability. Significant variation in binding affinities was observed, with cis-sabinene exhibiting the strongest adsorption driven by favorable hydrophobic interactions within the CD-MOF cavity, while β-phellandrene demonstrated weaker binding attributed to less optimal molecular fit. MD simulations further confirmed the stable encapsulation of hydrophobic compounds, including d-limonene, α-elemol, α-phellandrene, and elemicin within the CD-MOF structure. Despite conformational adjustments during simulation, these complexes maintained high structural integrity, as evidenced by consistently low root-mean-square deviation (RMSD) and radius of gyration values. These results underscore the critical role of non-covalent interactions, particularly van der Waals forces, and reveal the inherent structural flexibility and robustness of CD-MOFs in accommodating diverse hydrophobic guest molecules. This work demonstrates the strong potential of CD-MOFs as versatile and effective carriers for the encapsulation and stabilization of hydrophobic essential oil components, paving the way for their application in advanced delivery systems across pharmaceutical, cosmetic, and food industries.