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Magnetic Cobalt Oxide (CoO/Co₂O₃/Co₃${\text{O}}_4)$ and Nickel Oxide (NiO) Nanoparticles have been widely reported as heterogeneous catalysts for the preparation of derivatives of heterocycles. These are abundant, eco-friendly, relatively nontoxic and inexpensive catalysts. This review consists of the previous 10-year publications on the catalytic applications of Cobalt Oxide and Nickel Oxide Nanoparticles for the synthesis of heterocycles and their derivatives. Among the various metal oxide nanomaterials reported in the literature as catalyst materials for the synthesis of varied heterocycles and their derivatives, we have kept our focus on the key materials viz. Cobalt Oxide and Nickel Oxide Nanoparticles. In the conclusion part, we have also commented on the better options for the catalyst selection among the reports covered in this paper. This paper will definitely be useful for new researchers in the metal oxide nanomaterials-based catalytic applications for synthetic heterocyclic compounds.

This study investigates the synthesis and characterization of graphene oxide (GO) and its reduced form, reduced graphene oxide (rGO), focusing on their structural, physicochemical and electrochemical properties. Graphene oxide was synthesized from graphite flakes using the modified Hummer’s method, and hydrothermal reduction with ascorbic acid, which was employed to convert GO into rGO, forming a two-dimensional structure with a high surface area. The structural transformations were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), which revealed a significant reduction in interlayer spacing and restoration of the $s{p}^2$ hybridized carbon network in rGO, confirming the successful reduction of GO. Chemical modifications were characterized through Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible (UV–Vis) spectroscopy and X-ray photoelectron spectroscopy (XPS). These techniques demonstrated a marked decrease in oxygen-containing functional groups in rGO, indicating effective reduction and restoration of graphitic structure. Electrochemical studies using cyclic voltammetry demonstrated that rGO-modified carbon paste electrodes (rGO/MCPE) offer superior sensitivity and enhanced electron transfer efficiency. The effects of scan rate, concentration and pH were also evaluated, underscoring its potential for high-sensitivity detection applications. These findings highlight the potential applications of GO and rGO in electrochemical sensors, particularly for detecting biomolecules like serotonin, as well as in energy storage devices such as supercapacitors and batteries, where their high surface area and conductivity offer significant advantages.

The paper provides an overview of the significance of nanomaterials as additives, in the tribological performance of lubricants. This review describes the ascendancy of different nanoparticles such as carbon-based nanoparticles, metallic nanoparticles, oxide nanoparticles, sulphide nanoparticles, nanocomposites, hybrid and bimetallic nanoparticles in lubricants. The study also evaluates the underlying principles of lubricant-nanoparticle interactions and their effects on wear prevention and friction reduction. The key parameters including particle morphology, particle size, weight concentration, and functionalization of the particle surface, that determine the friction and wear characteristics are discussed. Also, the science behind surface interaction and various mechanisms involved in friction and wear modification is described. The review highlights the prospect of various nanomaterials in the field of lubrication and facilitates development of advanced nanolubricants with superior tribological properties, that attributes to the reduction in energy consumption and improved performance.

The latent heat storage system is considered the most promising technology in thermal energy storage (TES) because of its many advantages. This technique uses phase change material (PCM) as a TES medium. However, the low thermal conductivity (TC) of PCM is the major drawback of the system. Previous studies have shown that the addition of nanomaterials to PCM generally increases its TC. On the other hand, researchers tend to study the possibility of using enhanced PCM to cool solar cells. In fact, raising the solar cell’s operating temperature negatively impacts its efficiency. This problem is considered one of the biggest problems in solar energy systems, and researchers are still working to solve it. This paper focused on the possibility of enhancing the TC of paraffin by adding different shapes of silver nanomaterials to it (silver nanoparticles, silver nanowires and nanohybrid with silver nanoparticles and silver nanowires). Nanomaterials were added at volume fractions of 0.5% and 1%. Then, the study examined the ability to use this improved material to reduce the temperature of solar cells. We used the “Solidworks” program to create a 3D system, and then we used the “Ansys Fluent” software to simulate five cases; PV without PCM, PV with PCM, PV with PCM enhanced by nanoparticles, PV with PCM enhanced by nanowires, PV with PCM enhanced by nanohybrid (a mixture of nanoparticles and nanowires). The results show that using PCM enhanced by nanowire at a volume fraction of 0.5% gave the best results in decreasing the temperature of PV. The average temperature of PV declined by 14.9${}^{\circ }$. In addition, the efficiency of PV rose by about 7.6%. Followed by using PCM enhanced by nanoparticles at a volume fraction of 1%. The average temperature of PV declined by 12.9${}^{\circ }$. Moreover, the efficiency of PV rose by about 6.6%.

X-ray diffraction (XRD) is one of the most essential techniques for characterizing various crystals. However, when nanocrystals are present, the diffraction peaks become significantly broadened and reduced in intensity, making phase and microstructure analysis challenging. To obtain more refined microstructural information from nanocrystals, various methods have been developed to enhance diffraction peaks, with step scanning being a commonly used approach. Additionally, increasing instrument broadening (IB) by adjusting slit sizes to enlarge the irradiation area is a convenient yet often overlooked method. In this study, the effects of IB on the diffraction peak intensities of nanocrystals and micron crystals in mixed materials were thoroughly investigated. The results show that the intensities of both nanocrystals and micron crystals increase as IB increases, a behavior similar to that observed when extending the testing time during step scanning. However, the rate of increase in peak heights for nanocrystals is higher than for micron crystals, while the rate of increase in peak width for nanocrystals is lower, which is a significant departure from the effects seen in step scanning. In other words, nanocrystal peaks become sharper and more distinct as IB increases. This phenomenon is explained by the different components of peak width for nanocrystals and micron crystals, based on Lorentz mathematical model analysis. Based on these findings, it is recommended to utilize larger IBs in combination with step scanning to further reinforce nanocrystal peaks in mixed materials.

Regarding diagnosis, treatment, monitoring, and prognosis, nanomedicine will play a critical role in customized medicine in the future. Nanomedicine allows for better targeting, more accurate disease mapping, and fewer side effects by delivering drugs straight to the sick cells. The advantageous alterations that nanotechnology makes to the physiochemical, mechanical, magnetic, electrical, and optical properties of computing materials enable the development of new and innovative products. Food security, processing, coloring, nutritional absorption, flavor, nutrition, delivery, disease detection, food functioning, environmental protection, and cost-effective storage and distribution are a few of the important links between nanotechnology and food systems. Nanomaterials are used in biofuel production, wastewater treatment, biosensor pollution removal tools, photocatalysts, biomedical imaging and cancer treatments, and wearable chemical and environmental sensors, as shown by a number of academic publications. A few of the main challenges facing the application of nanotechnology are scalability, increased production rates, managing unwanted byproducts, repeatability and quality control of nanomaterials, and enhanced manufacturing rates.

${\mathrm{\text{TiO}}}_2$ nanomaterials with different content of ${\mathrm{\text{Ce}}}^{4+}$ ion were synthesized by the chemical method from solutions and demonstrated improved photocatalytic and optical properties with significant redshift compared to pristine ${\mathrm{\text{TiO}}}_2$. According to X-ray phase analysis and transmission electron microscopy, all synthesized materials are characterized by anatase modification, which holds up to $800^{\circ }$C, the particle size for all materials is 12–21 nm. X-ray diffraction spectra revealed that the anatase to rutile phase transition for materials doped with ${\mathrm{\text{Ce}}}^{4+}$ ions begins at a higher temperature of $800^{\circ }$C compared to pristine ${\mathrm{\text{TiO}}}_2$. The influence of synthesis conditions and ${\mathrm{\text{Ce}}}^{4+}$ content (0.1–2 mol.%) on characteristics and photocatalytic activity were investigated. The Ce-doped ${\mathrm{\text{TiO}}}_2$ nanomaterial, containing 0.1% ${\mathrm{\text{Ce}}}^{4+}$ provides an extremely high degree of methylene blue decomposition by 93% within visible light irradiation for 3 h. The stability of the catalyst over four cycles has been shown, which makes it possible to use it in the purification of water resources from dyes or other pollutants.

Infectious diseases are illnesses caused by pathogenic microorganisms, including viruses, bacteria, fungi, and parasites. These diseases can be transmitted from one individual to another, as well as through contaminated food, water, and insect bites, infectious agents invade the body, multiply, and disrupt normal bodily functions, leading to various health issues. However, due to antimicrobial resistance, the need to develop nanoenabled medicine gained significant attention recently. The management of infectious diseases using carbon nanotubes (CNTs) is an emerging field that leverages the unique properties of these nanostructures for enhanced drug delivery and therapeutic applications. Therefore, this review explores the transformative potential of CNTs in the diagnosis, prevention, and treatment of infectious diseases. As global health challenges escalate due to emerging pathogens and increasing drug resistance, the need for innovative solutions becomes critical. Moreover, the review systematically examines the unique properties of CNTs, including their mechanical, thermal, and electrical characteristics, that make them suitable for various biomedical applications. Further, the review highlights recent advancements in CNTs-based technologies, focusing on their roles in biosensing, drug deliver, and antiviral agents. Furthermore, the review also discusses how CNTs enhance the sensitivity and specificity of diagnostic tools, enabling rapid detection of infectious agents. Additionally, the multifunctional capabilities of CNTs in therapeutic applications, such as targeted drug delivery and pathogen inactivation, are also discussed. Challenges related to the clinical translation of CNTs technologies, including safety, biocompatibility, and regulatory concerns, are critically analyzed. In addition, the review concludes with clinical data by emphasizing the need for interdisciplinary collaboration to harness the full potential of CNTs in the management of infectious diseases, paving the way for future research and development in this promising field.

This paper proposes a generative model and transfer learning powered system for classification of Scanning Electron Microscope (SEM) images of defective nanofibers (D-NF) and nondefective nanofibers (ND-NF) produced by electrospinning (ES) process. Specifically, a conditional-Generative Adversarial Network (c-GAN) is developed to generate synthetic D-NF/ND-NF SEM images. A transfer learning-oriented strategy is also proposed. First, a Convolutional Neural Network (CNN) is pre-trained on real images. The transfer-learned CNN is trained on synthetic SEM images and validated on real ones, reporting accuracy rate up to 95.31%. The achieved encouraging results endorse the use of the proposed generative model in industrial applications as it could reduce the number of needed laboratory ES experiments that are costly and time consuming.

Electronic characteristics are difficult to monitor in nanocomposites. Here we describe indirect assessments of these characteristics using THz, Raman and IR spectroscopy. Specifically we seek to gain understanding of the electron mobility in semiconductive and conductive nanostructures for electronic, electrooptic and nonlinear optical purposes.

Volatile organic compounds (VOCs) are important biomarkers in exhaled breath or skin secretion of patients under various medical or pre-medical conditions. As such, VOCs have been explored as alternative biomarkers in the detection of diseases, including asthma, tuberculosis, and lung cancer. In this regard, a rapid, cost-effective, facile, and sample-free strategy is advantageous and critically needed for premedical screening, medical diagnosis, and health monitoring. In this review, we present an overview of the latest progress of using nanomaterial-based chemo-resistive VOC sensors for fast, real-time, and non-invasive diagnosis of diseases via detecting VOCs from exhaled breath and other sources from human body. The origin and emission of VOCs are summarized from human body, and the VOC signatures are discussed as related to specific disease. Targeting specific VOCs, chemoresistive sensors using different nanomaterials are reviewed in terms of their sensing performance metrics including sensitivity, selectivity, response/recovery time, and stability. Various strategies for improving VOC sensor performance are discussed, specifically on the material and signal processing-based approaches.

A set of Benzorod arrays on a graphene substrate has been investigated by performing classical molecular-dynamics simulations. Benzorod is composed of aligned and dehydrogenated benzene rings that are stacked to form a rod-like structure. It has been found that the arrays considered are thermally stable up to elevated temperatures, with a dependence on length.

Computer modeling was applied to the study of $(n,\alpha )$ transmutations in ${\mathrm{\text{Si}}}_3{\mathrm{\text{N}}}_4$ nanoparticles under the influence of neutrons at different energies. The modeling was separately performed for each Si and N atoms in the ${\mathrm{\text{Si}}}_3{\mathrm{\text{N}}}_4$ nanoparticles and the effect of neutrons on transmutations was investigated. The simulations were conducted individually for each stable isotope due to different effective cross-section of the probability of transmutation in the different types of isotopes of silicon and nitrogen atoms. Effective cross-section spectra of $(n,\alpha )$ transmutation in Si and N atoms were comparatively studied.

In order to study nanostructured materials, a fundamental framework of the theory and the computer-experimental studies is established. The essential characteristics of the mesoscopic phase transitions and critical phenomena in these materials are evaluated by means of this approach. For nanostructured materials consisting of inert gas atoms, we study mesoscopic phase transitions and critical phenomena by generalizing the renormalization theory and the Metropolis Monte Carlo method. The results obtained by the both methods are reported in two papers: computational results in the present paper and the theoretical results in the paper which follows.

Transparent mesoporous TiO₂ films consisting of uniform anatase particles have been deposited on glass slides by using sol-gel technique. A Europium complex Eu(TTA)₃(bpy), where the TTA ligand is β-diketonate thenoyltrifluoroacetonate and the bpy is 2,2-bipyridine, was formed on TiO₂ surface by physical adsorption of europium ions and successive formation of stable chelate complexes with TTA and bpy ligands. In this way a well dispersion of the complex has been achieved giving significant emission intensity. The excitation of the material in the UV region (374 nm) results in the emission of a nearly monochromatic light at 613 nm (⁵D₀→⁷F₂) via energy transfer from the excited organic ligands to europium emissive state.

A soft approach has been described for the formation of α–Fe₂O₃ nanorods by simple reaction of iron with water at a very low temperature range of 100–300°C. It is shown that the nanorods have diameters ranging from 50–80 nm, and their typical lengths are in the range of 5–10 μm. The chemical composition and crystalline structure of nanorods were investigated by various characterization techniques. The initial formation and subsequent growth of α–Fe₂O₃ nanostructures may be explained by the iron metal corrosion mechanism.

Pure nanocrystalline forsterite (Mg₂SiO₄) powder was successfully synthesized by mechanochemical route and subsequent annealing. The starting materials were talc (Mg₃Si₄ O₁₀(OH)₂) and magnesium carbonate (MgCO₃) powders. To produce forsterite powder, first talc and magnesium carbonate powders were calcined at 1200°C for 1 h and 700°C for 2 h, respectively. After that the mixture of obtained powders was milled by a planetary ball mill, and then annealed at 1000°C and 1200°C for 1 h. Thermogravimetric (TG) analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques were utilized to characterize the initial and prepared powders. The results showed that a single phase nanocrystalline forsterite powder with a crystallite size of 49 nm was obtained after 40 h milling and subsequent annealing at 1000°C for 1 h.

The exchange–coupling interaction between soft and hard phase layers and the effective anisotropy K_eff have been investigated by putting forward an expression of anisotropy at grain interface, , which is suitable for different coupling conditions in multilayered thin film. The results showed when the dimensions of soft and hard phases are the same (described by b), K_eff increases first, then decreases, and reaches a maximum at a certain value of b with increasing b. For the given hard phase dimension b_h, K_eff decreases monotonously with increasing soft phase dimension b_s. However, for the given b_s, K_eff increases monotonously with the increase of b_h. When the dimensions of soft and hard phases are the same, the variation of K_eff in multilayered thin film is very similar to that of coercivity given by Yang et al. Our results explained the experimental phenomenon better.

PbTiO₃ (PT) nanoparticles have been prepared by chemical route using polyvinyl alcohol (PVA) as an efficient surfactant. The effect of PVA to reduce the particle's sizes of PT has been observed. X-ray diffraction (XRD) pattern shows that the PT nanoparticles are tetragonal with distortion ratio, c/a ~1.061. The average particle's size calculated from XRD and transmission/scanning electron microscopy is ~24 nm for PT powder sintered at 700°C. The nanostructured grains were also observed in PT pellet sintered at 1000°C. The dielectric properties of PT pellet have been measured from room temperature to 200°C and in the frequency range of 0.075 to 10 MHz. The values of room temperature dielectric constant and tanδ are 117 and 0.05 respectively, measured at 0.5 MHz. It is found that the dielectric constant of PT nanoparticles can be controlled up to higher frequency region of 5 MHz.

A hexapod-like lead sulphide (PbS) nanostructure with six symmetric arms were investigated by Raman spectrum. The first order longitudinal optical phonons (1–LO) and second order longitudinal optical phonons (2–LO) vibration modes locate at 205 cm^-1 and 456 cm^-1, respectively. The transverse optical ( TO ) mode and combination modes (LO+TO and TO+TA) exist in the low frequency area. In air circumstance, the surface of PbS nanomaterials can be easily damaged by laser with power ~1.2 mW. The vacuum circumstance can avoid from photodegradation efficiently. Therefore, both irradiation by enough power laser and oxygen condition are necessary conditions for the photodegradation of PbS nanomaterials.