In this study, a hydrothermal technique was used to synthesize lead sulfide (PbS) and silver (Ag)-doped PbS nanoparticles (NPs) at different concentrations of 20, 40, and 60% of Ag. The small lattice phase changes appeared due to the shifting of diffraction angle peaks toward higher 2 θ for samples doped with PbS with increasing Ag content. The analysis of average crystallite size, phase structure, and lattice constant was observed under X-ray diffraction. The value of crystallite size, volume of the unit cell, and porosity (%) were found to increase with the increasing concentration of Ag NPs in PbS. The pure PbS crystallite size is small compared to Ag-doped PbS. The optical characteristics including absorption spectra of the prepared samples were investigated and confirmed by using scanning electron microscope and UV-Vis spectroscopy. The observation of the composition showed that higher doping concentrations of Ag lead to an increase in particle size. Absorption peaks in the UV-Vis spectra corresponding to pure and 20, 40, and 60% of Ag/PbS were observed at different wavelengths of 368, 369, 371, and 372 nm, respectively. Fourier transformation infrared spectroscopy peaks were found in the vibration mode of the ions due to the increment in Ag doping concentrations. These results indicate the possibility of tuning the optical structural properties of Ag-doped PbS through doping various concentrations of Ag NPs. Ag-doped PbS is considered promising future semiconductor nanomaterial, which will enhance the efficiency of photovoltaic device applications.

Recent developments propose renewed use of surface-modified nanoparticles (NPs) for enhanced oil recovery (EOR) due to improved stability and reduced porous media retention. The enhanced surface properties render the nanoparticles more suitable compared to bare nanoparticles, for increasing the displacement efficiency of waterflooding. However, the EOR mechanisms using NPs are still not well established. This work investigates the effect of in-situ surface-modified silica nanoparticles (SiO₂ NPs) on interfacial tension (IFT) and wettability behavior as a prevailing oil recovery mechanism. For this purpose, the nanoparticles have been synthesized via a one-step sol-gel method using surface-modification agents, including Triton X-100 (non-ionic surfactant) and polyethylene glycol (polymer), and characterized using various techniques. These results exhibit the well-defined spherical particles, particularly in the presence of Triton X-100 (TX-100), with particle diameter between 13 to 27 nm. To this end, SiO₂ nanofluids were formed by dispersing nanoparticles (0.05 wt.%, 0.075 wt.%, 0.1 wt.%, and 0.2 wt.%) in 3 wt.% NaCl to study the impact of surface functionalization on the stability of the nanoparticle suspension. The optimal stability conditions were obtained at 0.1 wt.% SiO₂ NPs at a basic pH of 10 and 9.5 for TX-100/ SiO₂ and PEG/SiO nanofluids, respectively. Finally, the surface-treated SiO₂ nanoparticles were found to change the wettability of treated (oil-wet) surface into water-wet by altering the contact angle from 130° to 78° (in case of TX-100/SiO₂) measured against glass surface representing carbonate reservoir rock. IFT results also reveal that the surfactant treatment greatly reduced the oil-water IFT by 30%, compared to other applied NPs. These experimental results suggest that the use of surface-modified SiO₂ nanoparticles could facilitate the displacement efficiency by reducing IFT and altering the wettability of carbonate reservoir towards water-wet, which is attributed to more homogeneity and better dispersion of surface-treated silica NPs compared to bare-silica NPs.

Carbon nanotubes have long attracted great scientific interest because of their simplicity, ease of synthesis and unique properties. The novel properties of nanostructured carbon nanotubes including its high surface area, stiffness, tensile strength, thermal and electrical properties which become suitable for the application in the fields of energy storage, hydrogen storage, electrochemical supercapacitor, field-emitting devices, transistors, nanoprobes and sensors, composite material, templates, etc. In this study, carbon nanotubes were synthesized through arc discharge plasma with two different configurations, transverse and axial field, applied across arc plasma synthesis process to enable a much rapid rate growing of tubular carbon multi-walled carbon nanotubes (MWCNTs). TEM, FESEM, RAMAN, FTIR and XRD were used to investigate the morphology and structural evolution of the MWCNTs samples produced with different synthesize environment. Introduction of magnetic field during the MWCNTs synthesized through arc discharge plasma technique has also been found to enhance the carbon nanotube growth, increase the high aspect ratio and its chemical stability, and shows potential for regulating the number of walls formed.

Polystyrene/Silica Nanocomposites (PS/Si NCs) are attractive material due to their stability (chemical and thermal), low toxicity, the probability from controlling their particle size, ability to be functionalized with a range of molecules and polymers, biocompatibility, degradability below physiographic statuses and low-cost production of materials. In that paper now, The procedure to fabricate polystyrene/silica (PS/SiO₂) hybrid hollow spheres did successfully combine by precipitation technique, which was then used to react with silica nanoparticles that were prepared by the sol-gel method to fabricate PS/SiO₂ nanocomposite. Four Point Probe, Transition electron microscopy (TEM), and XRD are used to analyze the physical, chemical, optical properties and electric of polystyrene/SiO₂ nanocomposites. The experimental effects indicate the possibilities for PS/SiO₂ to be used as biomaterials, coating and catalyst materials.

A First-principles research based on density functional theory is used to explore the various properties of pure and Sr-doped-KNbO_3-perovskites compounds such as structural, electronic, magnetic, and optical characteristics. The Sr impact on structural, optical, electronic, and magnetic properties of Sr-doped-KNbO₃ are investigated using ultra-soft pseudo-potential. The band gap of Sr-doped-KNbO₃ is found to be remarkably increased from 1.50 eV to 1.83 eV after the doping of Strontium (Sr) with various percentages (0%, 12.5%, 25%, 37.5%). Under the DFT study, strontium(Sr) is appropriate material for increasing the band gap of KNbO₃. Owing to the difference in ionic radii of Mo and Sr volume of crystal cells also decreased from 82.68 to 42.89 A³ after the doping of Strontium (Sr). The bandgap nature is found indirect furthermore bandgap showed that the material is a prominent semiconductor. A significant increment is obtained in the optical conductivity and also bandgap. After the doping of strontium (Sr) impurities, the energy absorption peaks are amplified. It is also observed that due to Sr substitution optical conductivity shifted toward higher energies. Sr-doped-KNbO₃ has enhanced optical conductivity, energy absorption, and refractive index, making it an appropriate material for perovskite solar cell applications.