In recent years, organic pollutants have become a global problem due to their negative impact on human health and the environment. Photocatalysis is one of the most promising methods for the removal of organic pollutants from wastewater, and oxide semiconductor materials have proven to be among the best in this regard. This paper presents the evolution of the development of metal oxide nanostructures (MONs) as photocatalysts for ciprofloxacin degradation. It begins with an overview of the role of these materials in photocatalysis; then, it discusses methods of obtaining them. Then, a detailed review of the most important oxide semiconductors (ZnO, TiO₂, CuO, etc.) and alternatives for improving their photocatalytic performance is provided. Finally, a study of the degradation of ciprofloxacin in the presence of oxide semiconductor materials and the main factors affecting photocatalytic degradation is carried out. It is well known that antibiotics (in this case, ciprofloxacin) are toxic and non-biodegradable, which can pose a threat to the environment and human health. Antibiotic residues have several negative impacts, including antibiotic resistance and disruption of photosynthetic processes.

Polymer nanocomposite films based on poly(vinyl pyrrolidone) incorporated with different amounts of copper oxide (CuO) nanoparticles were prepared by the solution casting technique. The PVP/CuO nanocomposites were analyzed by X-ray diffractometry (XRD), scanning electron microscopy, UV–Visible absorption spectroscopy and dielectric spectroscopy. The XRD analysis showed that the monoclinic structure of cupric oxide was maintained in the PVP host matrix. The key optical parameters, such as optical energy gap E_g, Urbach energy E_U, absorption coefficient and refractive index, were estimated based on the UV-Vis data. The optical characteristics of the nanocomposite films revealed that their transmittance and absorption were influenced by the addition of CuO nanoparticles in the PVP matrix. Incorporation of CuO nanoparticles into the PVP matrix led to a significant decrease in band gap energy and an increase in the refractive index. The dielectric and electrical behaviors of the PVP/CuO nanocomposites were analyzed over a frequency range between 10 Hz and 1 MHz. The effect of CuO loading on the dielectric parameters (dielectric constant and dielectric loss) of the metal oxide nanocomposites was also discussed.

In this study, we report the synthesis and characterization of Fe₃O₄ nanoparticles coated with dextran. The structural and optical properties of the Dx:Fe₃O₄ synthesized composites were investigated by Fourier Transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and UV–Vis absorption spectroscopy. For the first time in this paper, the photophysics of Dx:Fe₃O₄ composites in water is studied using fluorescence and phosphorescence molecular spectrometry. An analysis of the absorption spectra of the Dx:Fe₃O₄ composite reveals the broad absorption bands with maxima at wavelengths of 227 nm, 264 nm, and 340 nm. Dx:Fe₃O₄ composite nanoparticles in water exhibit strong fluorescence with a quantum yield of 0.24% in contrast to 0.07% for dextran. Phosphorescence spectra confirm the formation of new emission bands within the Dx:Fe₃O₄ solution evidenced by the maxima shift for both dextran and Dx:Fe₃O₄ composites.

In this study, zinc phthalocyanine (ZnPc) and copper phthalocyanine (CuPc) thin films fabricated by drop casting (DC) and close space sublimation (CSS) have been investigated and compared with ZnPc and CuPc solutions in formic acid (29 µmol/L). The results show that the CSS method produces films with improved molecular ordering, enhanced surface uniformity, superior optical and morphological properties compared to those obtained by drop casting. Moreover, CSS allows a precise and reproducible deposition, resulting in thinner, homogeneous layers with strong substrate adhesion and fewer defects. Optical characterization confirms that CSS films display high transparency (~90%), a sharp Q-band around 680 nm, and a fluorescence maximum at ~825 nm with the strongest emission intensity.In contrast, DC films show lower transparency (<70%), a slightly shifted Q-band (~675 nm), and similar emission around 825 nm. The fluorescence is strongly thickness-dependent: at ~100 nm, the emission band appears at 795 nm, while films thicker than 300 nm exhibit a red-shifted maximum at ~825 nm. AFM analysis further demonstrates the influence of deposition method: CSS yields smoother films with tunable morphology, while DC produces rougher, less controllable surfaces. Overall, CSS is shown to be the more effective approach for fabricating high-quality phthalocyanine films for optoelectronic applications such as photovoltaics and sensors.

This study presents a comprehensive investigation of the structural, morphological, and optical properties of aluminum phthalocyanine (AlPc) and silicon phthalocyanine (SiPc) thin films prepared by the close space sublimation (CSS) method, deposited at different evaporator temperatures of 350 °C, 400 °C, and 450 °C, including heterostructures incorporating an indium tin oxide (ITO) layer. Scanning electron microscopy revealed a clear temperature-dependent evolution of surface morphology, with both materials transitioning from isolated crystallites to dense, highly crystalline films. SiPc exhibited higher nucleation density and earlier film densification, while AlPc showed more pronounced grain growth at elevated temperatures, accompanied by crack formation due to internal stress. Optical absorption spectra indicated a red shift in absorption maxima with increasing deposition temperature, associated with improved crystallinity and reduced defect density. The presence of ITO significantly modified the optical response, introducing additional absorption features in the near-infrared region due to interference effects and free-carrier contributions. Fluorescence measurements revealed enhanced emission intensity with increasing temperature for AlPc, while SiPc showed weaker emission overall. The incorporation of ITO led to substantial fluorescence enhancement and the appearance of additional near-infrared emission bands, highlighting the importance of interface engineering. Transmittance spectra demonstrated that ITO-based heterostructures provide a balance between transparency and absorption, with selective attenuation in the 600–800 nm range, enabling band-stop filter behavior. Raman analysis revealed opposite temperature-dependent trends: increasing structural order in AlPc and gradual disorder in SiPc. X-ray diffraction confirmed the crystalline nature of both materials, showing temperature-induced improvements in crystallinity and crystallite size, as well as distinct differences in molecular packing and preferred orientation. These results demonstrate the potential of AlPc and SiPc thin films as functional optical materials with tunable structural and optical properties.