Papers by Keyword: Nanoparticles

Abstract: This study assesses the photovoltaic potential of pure Bismuth Ferrite (BiFeO₃) and its doped variants, specifically Samarium (Sm)-doped and Cobalt–Samarium (Co–Sm) co-doped BiFeO₃ nanoparticles. The materials were synthesized using sol-gel methods, followed by post-annealing to promote high crystallinity. A comprehensive characterization was performed to evaluate the structural, morphological, and optical properties utilizing X-ray diffraction (XRD), Field-Emission Scanning Electron Microscopy (FESEM), and UV-Vis spectroscopy. The findings indicate that doping and co-doping have a substantial influence on the optical bandgap, particle morphology, and crystallite dimensions. Sm and Co–Sm doping reduced the bandgap, enhancing visible-light absorption and solar energy-harvesting efficiency, whereas pure BiFeO₃ exhibited a bandgap of 2.03 eV. Electrical investigations further revealed greater charge separation, underscoring the superior charge-transport properties of the modified materials. The results indicate that doped BiFeO₃ systems hold potential as tunable multiferroic materials for advanced, high-efficiency solar applications.

Abstract: A typical Nebulizer Spray Pyrolysis (NSP) technology was used to produce and deposit CuO nanoparticles on glass substrates. In this work, the effects of different precursor volumes on the properties of CuO thin films produced by Nebulizer Spray Pyrolysis (NSP) were investigated. In this work, CuO thin films have been developed using the NSP approach with three different precursor quantities (3, 4, and 5 ml). A monoclinic crystal structure was found using X-ray diffractometry (XRD), which was confirmed to be consistent with JCPDS card No. (89-5899). The XRD studies have been used to calculate the dislocation density, micro strain, and crystallite size. The average thickness was measured using a surface profilometer. High-resolution Schottky emitter FE-SEM has been used to study morphological properties, and the results demonstrate that each film has been evenly deposited on the glass substrate. The presence of the element in the CuO thin films has been confirmed by energy dispersive X-ray analysis (EDAX). Transmission values ranging from 20% to 65% at varied volumes were achieved, according to the optical measurements. The energy band gaps were determined using tauc plots to be between 1.85 eV and 2.15 eV, with 4 ml having the lowest band gap value at 1.85 eV. CuO thin-film’s electrical conductivity was measured in DC, and the highest conductivity value for 4ml was 2.5x10^-8 S/cm.

Abstract: The decline in conventional oil recovery efficiency necessitates the development of advanced tertiary methods such as Enhanced Oil Recovery (EOR). This study investigates a hybrid nanofluid composed of acetylated cassava starch and silica nanoparticles for application in chemical EOR. Acetylated starch was synthesized to enhance viscosity and thermal stability, while silica nanoparticles were incorporated for their interfacial activity and wettability alteration capabilities. Comprehensive laboratory experiments were conducted to evaluate the hybrid fluid’s physicochemical, rheological, and recovery performance. Characterization using FTIR, XRD, SEM, and TGA confirmed successful functionalization and improved thermal resilience. Rheological tests demonstrated shear-thinning behavior with high viscosity retention. The hybrid fluid also achieved a 57.7% reduction in interfacial tension and altered sandstone wettability from oil-wet to strongly water-wet conditions. Core flooding tests revealed a recovery factor of 68.9%, outperforming starch-only, silica-only, and brine controls. The synergy between the polymer and nanoparticles enhanced colloidal stability, flow performance, and oil displacement efficiency under simulated reservoir conditions. The use of cassava starch as a biodegradable and locally sourced material underscores the environmental and economic viability of the formulation. These findings support the potential of acetylated starch–silica nanofluids as sustainable, high-performance EOR agents.

Abstract: Phase components of experimental low cost titanium alloys, their substructure and parameters, dislocation structure, features of phase formation in the metal, which differ in alloying systems, were studied using complex research methods. The stoichiometric composition of dispersed phases in the internal volumes of alloy grains was determined by diffraction patterns using transmission electron microscopy. It is shown that in the structure of titanium alloy Ti-2,8Al-5,1Mo-4,9Fe there are dispersed nanoparticles of intermetallic phases of different morphology and stoichiometric composition. These are the phases: Ti₃Al and Fe₂Ti with a size of 10…40 nm; Mo₉Ti₄ - 20…120 nm. Studies of titanium alloy Ti-1,5Fe-O showed the presence in the structure of mainly nanoparticles of oxides: Ti₃O₅ size 10…30 nm and Ti₄Fe₂O, FeTiO₅ (10…90 nm), as well as intermetallics Fe₂Ti (10…40 nm). It is established that the formation of nanoparticles of intermetallic and oxide phases in the thin plate structure of the investigated experimental low cost titanium alloys promotes the formation of the substructure with uniform distribution of dislocation density. This provides a high level of mechanical properties of alloys.

Abstract: Ice slurry offers a promising solution for enhancing energy efficiency and environmental sustainability in industrial refrigeration and thermal energy storage applications. This review critically examines the effects of additives and production methods on the thermo-physical properties of ice slurry, focusing on viscosity and heat transfer performance. Additives such as ethylene glycol (6.5–10.3%), sodium chloride (up to 9%), and propylene glycol (5–24%) significantly enhance heat transfer coefficients by up to 33%, while alumina-based nanofluids (0.2 wt%) increase thermal conductivity by as much as 67%. Optimal ice packing factors (10–25%) and advanced production techniques, including direct contact and fluidized bed methods, improve energy efficiency, scalability, and operational reliability while mitigating issues such as particle agglomeration and viscosity rise. The study emphasizes rigorous methodological transparency with explicit equation definitions, controlled variables, and standardized measurement units (e.g., W/m²K for heat transfer, kg/m·s for viscosity). These findings provide valuable insights to guide the development of robust, high-performance ice slurry systems for large-scale cooling and energy storage applications.

Abstract: Zinc oxide is the most widely used nanomaterial in nanotechnology due to its outstanding properties and characterizations. Enormous attention has arisen due to its unique physical properties consists of a wide energy band gap of 3.37 eV at ambient temperature and large binding energy of 60 meV, which give development to an extensive range of potential applications in many areas such as electronics, solar cells, and biological applications. The size and shape of nanoparticles are significant to ensure the process becomes faster, cheaper and more efficient compared with traditional methods. By having more active area of nanoparticles, the biological and chemical process become more effectives. The biological activity of ZnO Nanoparticles was investigated through the antibacterial activity, anti-microbial activity, as anticancer and antioxidant material. The method used to prepare the ZnO Nanoparticles also take an important part which is to reduce the by-product formation when applied in wastewater treatment. This article summarizes different preparation methods of ZnO Nanoparticles and its application uses. The ZnO nanoparticles can be used the various applications, for example for the antibacterial, anti-cancer, anti-microbial, antioxidant and for wastewater treatment applications.

Abstract: The modification of titanium dioxide (TiO₂) with zirconium dioxide (ZrO₂) supported by chitosan (CS) was carried out to obtain a binary oxide system, which should have the properties of both components such as high stability, solar propulsion, non-toxicity and good corrosion resistance. The sample with a ratio of 1:1:3 (TiO₂:CS:ZrO₂) showed the best results with a photocatalytic degradability of 99 % after 90 minutes at a pH of 7 and in 10 ppm Malachite Green (MG). Under visible light, the photocatalytic degradability of the CS/TiO₂-ZrO₂ hybrid was more than 90 %. The enhanced photocatalytic degradation of MG by hybrid catalyst beads was attributed to the synergistic effect of hybrid CS/TiO₂-ZrO₂.

Abstract: Ni and Ni-containing nanoparticles exhibit promising magnetic properties. In a preliminary experiment, these nanoparticles aggregated after synthesis. Because nanoparticle aggregation may degrade their unique properties, a method to prevent their aggregation is required. In this study, Ni-Pt nanoparticles were synthesized and coated with silica to suppress aggregation. A colloidal solution of Ni-Pt nanoparticles was synthesized in water exposed to air using nickel(II) acetate tetrahydrate (Ni source), hexachloroplatinate(IV) hexahydrate (Pt source), sodium borohydride (reducing agent), and citric acid (stabilizer). Silica-coated Ni-Pt nanoparticles (Ni-Pt/SiO₂) were synthesized by adding a tetraethylorthosilicate (TEOS)/ethanol solution to the colloidal Ni-Pt nanoparticle solution. The morphology of the Ni-Pt nanoparticles varied with reaction time. The Ni-Pt/SiO₂ nanoparticles consisted of Ni-Pt cores and SiO₂ shells, with their morphology dependent on the TEOS concentration. Furthermore, the Ni-Pt/SiO₂ nanoparticles were more dispersed than the uncoated Ni-Pt nanoparticles, suggesting that the silica coating suppressed aggregation.

Abstract: Zinc oxide (ZnO) is a common photocatalyst for dye degradation, but its efficiency is limited by surface properties, photocorrosion, and pH sensitivity. This study functionalized ZnO with 2-aminophenol (ZnO-AP) to enhance dye adsorption and stability under varying pH. FTIR, XRD, and UV-Vis confirmed successful synthesis, with ZnO-AP showing a reduced band gap for improved visible light absorption. Photodegradation tests using Brilliant Blue G (BBG) revealed that ZnO-AP has the highest efficiency (36.17%) at pH 4, driven by strong electrostatic interactions. Performance decreased at pH 7 and 11 due to reduced dye adsorption, especially at basic pH with electrostatic repulsion. Functionalization also protected ZnO against photocorrosion, improving stability in acidic conditions. These results highlight 2-AP functionalization as a promising strategy to enhance the photocatalytic performance of ZnO across pH ranges.

Abstract: Copper sulphide (Cu₂S) is an indirect gap p-type semiconductor belonging to I-VI group. The wet chemical route was used to synthesize manganese (Mn) doped copper sulphide nanoparticles with a decrease in particle size by increasing the concentration of manganese element. These nanoparticles were analyzed by using the various characterization techniques like ultraviolet-visible (UV) absorption spectroscopy, photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM). The dip coating method was used to prepare Mn doped Cu₂S thin films on fluorine doped tin oxide (FTO) glass slides with varying the dip time. These thin films were heat treated in air atmosphere at 420°C for 20 minutes and investigated by using the various analysis techniques like scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive analysis by X-rays (EDAX) and mapping. The detailed explanation of obtained experimental results is discussed in this paper.