This work describes a novel method for converting bismuth triiodide (BiI₃) microplates into bismuth oxyiodide (BiOI) nanoflakes under ultrasonic irradiation. To produce BiOI nanoflakes with a high yield and high purity, the conversion process was carefully adjusted. Rapid reaction kinetics and increased mass transfer are benefits of the ultrasonic-assisted approach that result in well-defined converted BiOI nanostructures with superior characteristics. The produced BiOI nanoflakes were examined utilizing a range of analytical methods, such as Transmission Electron Microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The progress in the ultrasonic conversion process with time was monitored through diffuse reflectance spectroscopy (DRS). The outcomes demonstrated the effective conversion of BiI₃ microplates into crystalline, homogeneous, high-surface-area BiOI nanoflakes. Additionally, the degradation of organic dyes (methylene blue) under ultraviolet (UV) light irradiation was used to assess the photocatalytic efficacy of the produced BiOI nanoflakes. Because of their distinct morphology and electrical structure, the BiOI nanoflakes remarkably demonstrated remarkable photocatalytic activity, outperforming traditional photocatalysts. The ability of BiOI nanoflakes to effectively separate and utilize visible light photons makes them a viable option for environmental remediation applications. This work not only shows the promise of BiOI nanoflakes for sustainable photocatalytic applications but also demonstrates a simple and scalable approach to their manufacturing. The knowledge gathered from this work opens up new avenues for investigating ultrasonic-assisted techniques for creating sophisticated nanomaterials with customized characteristics for a range of technological uses.

In this work, epoxy composites filled with flake graphite of various size (less than 10 μm and less than 45 μm) were produced. The aim of the research was to develop a self-lubricating material with favorable tribological properties, i.e., reduced friction coefficient compared to unfilled epoxy resin and limited abrasive wear. The research material was produced using technical epoxy resins based on bisphenol A. The detailed process of composite production was described, and typical technological problems were considered. The addition of graphite led to an increase in dynamic viscosity, which positively limits the phenomenon of sedimentation, but an increase in the filler content also led to an increase in the porosity of the material. A series of tests have shown that the addition of graphite above 5% by weight allows for a reduction in the friction coefficient from 0.6 to 0.4 and significantly reduces the material’s tendency to abrasive wear.

Bismuth sulfide (Bi ₂ S ₃ ) is a chalcogenide semiconductor with a relatively narrow energy band gap that is promising for use in solar cells and photodetectors.

Modification of DSSC photoanodes by adding various types of materials is a widely used method to improve the performance of electrochemical devices. In this work, selected rare-earth oxide (RE₂O₃) nanoparticles, such as erbium oxide (Er₂O₃), holmium oxide (Ho₂O₃), neodymium oxide (Nd₂O₃), and ytterbium oxide (Yb₂O₃), were applied for photoanode preparation. A simple method for photoanode fabrication based on the direct mixing of oxide nanoparticles with TiO₂ paste was employed. The effect of variation in the rare-earth oxide content in the photoanode was investigated. The prepared composite photoanodes were characterized by XRD and FE-SEM for structural and morphological studies. XRD verified the anatase polymorph of TiO₂; FE-SEM with EDS mapping validated the uniform morphology of the anode and the distribution of RE₂O₃, as well as its amount. The photovoltaic parameters of modified DSSCs based on the current-voltage measurements were analyzed.