Journal of Nano Research Vol. 92

Abstract: A new 2D material structure, a brickwall structure, has been proposed using density functional theory (DFT). The structure was obtained from square lattice optimization. Based on the minimum energy results, the brickwall structure has smaller energy than the square structure. From the calculated density of states, the brickwall structure is metallic, like the square structure. The brickwall structure has a C_2v symmetry while the square structure has D_4h symmetry. This research opens opportunities for exploring new two-dimensional materials.

Abstract: We have carried out the density functional theory (DFT) calculations of substitutional, interchange, and Stone-Wales defects in monolayer hexagonal Boron Nitride (h-BN). We model four configurations: nitrogen substitution (S_B→N), boron substitution (S_N→B), interchange (I_B↔N), and Stone-Wales (SW). The calculated formation energies of S_B→N, S_N→B, I_B↔N, and SW are-186.50 eV, 200.45 eV, 7.48 eV, and 6.70 eV, respectively. In the case of substitutional defects, SB→N is more stable than SN→B, and the reaction is exothermic. The SW configuration has an energy 0.78 eV smaller than the I_B↔N configuration. During atomic relaxation, S_B→N and SW cause inward relaxation while S_N→B and I_B↔N cause outward relaxation. Furthermore, we calculated the density of states (DOS), and we show that new groups of states are formed around the Fermi level.

Abstract: Silver nanowires (AgNWs) have garnered significant attention for their applications in flexible electronics, sensors, and transparent conductive films. Traditional synthesis methods are often energy-intensive and involve hazardous chemicals. However, this study investigated a green synthesis approach using tannic acid as reducing and stabilizing agents, focusing on the effect of light intensity on nanoparticle formation. AgNWs were successfully synthesized at room temperature via a light-assisted reduction method using tannic acid. Various intensities of blue light with a wavelength of 456-467 nm were applied to determine their influence on the morphology AgNWs. Light intensity was found to play a crucial role in controlling the nucleation and growth rate of AgNWs. Higher intensities accelerated the reduction of Ag⁺ (silver ion) to Ag⁰ (silver atom), promoting the formation of longer nanowires with increased diameters. Furthermore, these AgNWs demonstrated good stability after one month of storage, with zeta potential values of-20.0 ± 1.01 mV. This study demonstrated that blue light intensity significantly affected the morphology of AgNWs synthesized using tannic acid, providing a sustainable and tunable method for fabricating high-aspect-ratio nanowires under mild conditions.

Abstract: Yttrium-doped ZnO aerogel nanostructures with low Y concentrations (0.5 and 1 at.%) were synthesized through a modified sol–gel process coupled with supercritical isopropanol drying, yielding highly porous and crystalline materials. Structural and optical characteristics were investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Utraviolet–Visible (UV–Vis) spectroscopy, and photoluminescence (PL) spectroscopy. XRD results confirmed the formation of single-phase polycrystalline ZnO with a hexagonal wurtzite structure for all samples, along with lattice perturbations consistent with the substitution of Zn²⁺ by Y³⁺ ions. FTIR spectra further supported successful ZnO network formation, revealing a systematic shift of the Zn–O stretching band toward lower wavenumbers upon Y incorporation. UV–Vis measurements showed that yttrium doping enhances optical absorbance and induces a slight redshift of the absorption edge, indicating a modest narrowing of the band gap. PL analysis demonstrated a remarkable enhancement in UV and visible emission for the ZnO:Y (0.5 at.%) sample, which exhibited the highest overall PL intensity across the investigated spectral range. This enhancement is attributed to an increased radiative recombination rate of photogenerated carriers and the formation of additional defect-related states introduced by low-level Y doping. These findings highlight the strong potential of yttrium-modified ZnO aerogels for tunable optical and photonic applications.

Abstract: Abstract. In this work, ZnO nanoparticles (NPs) were prepared using Thymus vulgaris extract and modified through copper doping and copper–lanthanum co-doping. Structural analyses (XRD, Raman, FTIR, SEM) confirmed the wurtzite crystal phase with polyhedral morphology across all samples. Distinct performance trends were observed depending on the doping strategy. Cu–ZnO demonstrated the highest insecticidal efficacy against Myzus persicae, achieving complete mortality within four days, and exhibited superior photocatalytic activity, removing 86.3% of methylene blue within one hour under visible light. In contrast, Cu–La–ZnO displayed enhanced antibacterial performance, producing the largest inhibition zones against Staphylococcus aureus (17 mm), Escherichia coli (15 mm), and Salmonella typhimurium (16 mm). These findings suggest that copper doping predominantly promotes reactive oxygen species generation, favoring insecticidal and photocatalytic functions, while the synergistic incorporation of lanthanum enhances antibacterial interactions.

Abstract: In this study, TiO₂ nanoparticles (NPs) were co-doped with silver (Ag) and gold (Au) via a solvothermal method conducted at for 30 min to enhance their structural, morphological, and optical properties. The TiO₂ samples were prepared as follow: pure TiO₂, TiO₂ doped with 0.5% Ag:1% Au, 1% Ag:0.5% Au and 1% Ag:1% Au NPs named as, S₀, S₁, S₂ and S₃, respectively. The samples were annealed at for 2 hours. Several characterizing methods namely; XRD, FTIR, AAS, FESEM, EDX and PL were used to investigate the presences of doping ratios with noble metals and their effects on the structural, morphological and optical properties of TiO₂. The XRD results revealed that the average crystallite size of the doped samples decreased compared to the un-doped TiO₂. The average crystallite size of S₀, S₁, S₂ and S₃ were found to be 13.56, 12.69, 11.76 and 11.49 nm, respectively, which can be related to the inhibition of crystal growth due to doping. FTIR analysis confirmed slight shifts and changes in intensity in O-H and C-O bands suggest the interaction between the TiO₂ matrix and the Ag/Au dopants, indicating successful surface modification and potential changes in surface chemistry. AAS revealed the presence of Ag and Au. The average particle size of S₀, S₁, S₂ and S₃ were found to be 23.82, 20.05, 19.25 and 18.89 nm, respectively. At the same time, element mapping images confirmed the homogeneous spatial distribution and incorporation of Ag and Au in the doped samples. PL analysis indicated that doping TiO₂ with Ag/Au NPs significantly decreases electron –hole recombination.

Abstract: In this study, we systematically evaluated the fluid loss reduction effect of four nanomaterials in high-temperature water-based drilling fluids. Compared to the natural polymer PAC, the synthetic acrylamide-based polymer-maintained integrity and reduced fluid loss from 36.25 mL to 14 mL after aging at 180 °C, while forming a thinner and less permeable filter cake. Among the nanomaterials tested, 0.5 wt.% TiO₂ showed the most significant fluid loss reduction after aging at 180 °C, significantly optimizing the particle size distribution and reducing the fluid loss. When the polymer was used in combination with TiO₂, a significant synergistic enhancement was observed, which reduced the fluid loss to a minimum value of 11.6 mL at 180 °C. Zeta potential, particle size analysis, and SEM images showed that the effect resulted from the improved colloidal stability, closer packing of the particles, and the formation of a dense filter cake structure. The results show that the nanomaterial-polymer composite system can significantly improve the high-temperature fluid loss reduction performance of drilling fluids through the dual mechanism of physical blocking and chemical interaction, which provides an effective strategy for the design of high-performance fluid loss reduction agents.

Abstract: Recent interests in hybrid polymers for fuel cell applications have given rise to the exploration, modification, and application of various polymer ionomers. Polymer membranes doped with suitable fillers have improved fuel cell performance compared to the pristine polymers. In this study, three ionomers, PAN, PVP, and PVA were synthesised idividually and then functionalised with zirconium phosphate nanoparticles as membrane nanofillers. The nanofibers were synthesised using the sol-gel polymerisation method from their respective precursors dissolved in either water or DMF solution. This was followed by their subsequent fabrication through the incorporation of the zirconium phosphate nanoparticles, which were synthesised from their precursor salt using the precipitation method. Techniques such as SEM, FTIR, TGA, and XRD were employed to characterise the physiochemical properties of the synthesised polymers. In addition, the electrochemical properties of the synthesised polymers were evaluated using CV and EIS. The obtained results showed that conductive nanofibers were successfully synthesized. As the scan rates increased under cyclic voltammetry, the reduction peak for PVP voltammograms disappeared, and the PAN exhibited an irreversible redox system. It is also noticeable that when scan speeds increase, the oxidation peaks for PAN voltammograms shift to higher potentials. On the other hand, the TGA results indicated that these nanoparticles had excellent thermal stabilities, making them suitable for use in fuel cell membranes under tough conditions. Based on these findings, PAN, PVA, and PVP polymer materials can be used as filler (dopant) materials for fuel cell membranes.

Abstract: In this study, SnO₂ was successfully synthesized using spray pyrolysis method. Knowing that lanthanides has the capability to enhance the performance of metal oxides in supercapacitor application, Samarium was loaded to Tin Dioxide (SnO2) at different percent weight concentrations (0.5%, 1%, 3% 5%). XRD diffractograms shows the formation of tetragonal rutile structure with prominent peaks at 26.6, 34.08, 51.94 that corresponds to (110), (101), and (211) respectively and no additional peaks was detected with the incorporation Sm³⁺ ions which. The data obtained from Energy Dispersive X-ray Spectroscopy confirm the presence of Sm on the spray pyrolyzed SnO2. Scanning electron micrograph revealed that the increase in loading of Sm changes the morphology of the samples from 1D to 2D structures. Faradaic reactions indicated by the oxidation and reduction peaks were monitored using cyclic voltammetry in 1M KOH electrolyte. The specific capacitances were determined by analyzing the galvanostatic charge discharge profile of each sample. SnO₂ with 0.5% Sm yield the the highest specific capacitance, energy density and power density of 54.55 F/g, 1.60 WHr/kg, and 230 W/kg respectively. The results from this research offers a valuable information in synthesizing binder-free electrode and modifying its properties by incorporating samarium. These electrodes can be used for advanced applications such as electrochemical energy storage device, electrochemical sensors, and electrocatalytic applications.

Abstract: Pb–Sn mixed perovskite solar cells offer narrow bandgaps suitable for high efficiency photovoltaic applications, yet numerical simulations often overestimate experimental performance due to neglected defect and interface losses. In this work, an experiment calibrated and uncertainty aware benchmarking framework for Pb–Sn perovskite solar cells is developed using drift diffusion modeling combined with Monte Carlo sampling. Series resistance and interfacial recombination parameters are calibrated against twelve experimentally reported devices to ensure quantitative agreement. Global sensitivity analysis based on Sobol indices and partial rank correlation coefficients identifies bulk trap density as the dominant efficiency limiting factor, contributing more than 70% of the total performance variance, followed by interfacial recombination. Statistical yield analysis reveals that efficiencies above 20% are only probabilistically achievable under strict trap suppression and optimized band alignment conditions. The framework provides reproducible, population level design rules for Pb–Sn perovskite devices and establishes a reliable modeling platform for performance prediction and manufacturability assessment.