In sustainable hydrogen generation, photoelectrochemical (PEC) water splitting stands as a crucial technology, offering solutions to the global energy crisis while tackling environmental challenges. PEC water splitting relies on metal oxide nanostructures due to their unique electronic and optical characteristics. This research highlights the development of a CuO-Fe₂O₃@g-C₃N₄ nanocomposite, created through the integration of three components and fabricated via a one-pot hydrothermal process, precisely engineered to enhance PEC water-splitting efficiency. The combination of CuO, Fe₂O₃, and g-C₃N₄ results in a unified heterojunction structure that efficiently mitigates issues associated with charge carrier recombination and structural stability. Additionally, the analyses of both the structure and composition confirmed the precise synthesis of the composite. The CuO-Fe₂O₃@g-C₃N₄ nanocomposite achieved a photocurrent density of 1.33 mA cm⁻² vs. Ag/AgCl upon exposure to light, demonstrating superior PEC performance and outperforming the individual CuO and Fe₂O₃ components. The enhanced performance is attributed to g-C₃N₄ acting as a photoactive material, generating charge carriers, while the combination of CuO-Fe₂O₃ enables efficient carrier separation and mobility. This synergistic interaction significantly enhances photocurrent generation and ensures long-term stability, positioning the material as a highly promising solution for sustainable hydrogen production. These results highlight the promise of hybrid nanocomposites in driving progress in renewable energy technologies, opening new avenues for the development of more efficient and long-lasting PEC systems.

Biomedicine requires materials able to respond to specific needs without affecting the organism. Organic–inorganic fibrillar polymeric matrices possess unique properties that may fulfill these needs. In the present study, different topology-controlled poly(ε-caprolactone)-based fibrillar matrices containing glycine betaine at varying concentrations (0.5, 1, and 2% w/v) were prepared via electrospinning. The matrices were used as substrates in calcium carbonate crystallization assays with gas diffusion to obtain a single organic–inorganic hybrid material. The resulting matrices and crystalline material were characterized using spectroscopic, microscopic, and thermogravimetric analyses. The incorporation of glycine betaine into a poly(ε-caprolactone) mesh modified the diameter of the fibers, without affecting the thermal behavior of the matrices. However, the chemical and morphological characteristics of the matrices did influence in vitro inorganic mineralization. The thermogravimetric analysis of the matrices, performed after the mineralization tests, demonstrated the existence of a new organic–inorganic hybrid material with unique properties, which is discussed in the present study.

A new series of [Fe_3−xLn_x]O₄ nanoparticles, with Ln = Gd; Dy; Lu and x = 0.05; 0.1; 0.15, was synthesized using the coprecipitation method. Analyses by X-ray diffraction (XRD), Rietveld refinement, and high-resolution transmission electron microscopy (HRTEM) indicate that all phases crystallized in space group $Fd\overline{3}m$, characteristic of spinels. The XRD patterns, HRTEM, scanning electron microscopy analysis (SEM-EDS), and Raman spectra showed single phases. Transmission electron microscopy (TEM), Rietveld analysis, and Scherrer’s calculations confirm that these materials are nanoparticles with sizes in the range of ~6 nm to ~13 nm. Magnetic measurements reveal that the saturation magnetization (Ms) of the as-prepared ferrites increases with lanthanide chemical substitution (x), while the coercivity (Hc) has low values. The Raman analysis confirms that the compounds are ferrites and the Ms behavior can be explained by the relationship between the areas of the signals. The magnetic measurements indicate superparamagnetic behavior. The blocking temperatures (T_B) were estimated from ZFC-FC measurements, and the use of the Néel equation enabled the magnetic anisotropy to be estimated.

The high-voltage spinel ${\mathrm{LiNi}}_{0.5}{\mathrm{Mn}}_{1.5}{\mathrm{O}}_4$ (LNMO) is a promising cobalt-free cathode material for lithium-ion batteries, yet its integration as a binder-free thin film on metallic current collectors via simple solution routes remains underexplored. Here, LNMO films were synthesized on 304 stainless steel (SS304) by metal–organic decomposition (MOD) from metal–acetate precursors in ethanol, followed by spin-coating and annealing at 500, 600, and 700 °C under flowing ${\mathrm{O}}_2$. The films were characterized by XRD, FESEM–FIB cross-sectioning, EDS, and XPS, and tested as binder-free cathodes by cyclic voltammetry and galvanostatic charge/discharge. All samples are dense, approximately 1.9 μm thick, and crystallize in the disordered spinel phase. The LNMO crystallite size increases from 21.9 to 43.8 nm between 500 and 700 °C, while the grain size also shows a temperature dependence, increasing the average size from 25 up to 56 nm in diameter. XPS confirms ${\mathrm{Mn}}^{4+}$ as the dominant manganese surface species (45–49%) across all samples. The films deliver reversible discharge capacities of 92, 92, and 70 mAh ${\mathrm{g}}^{-1}$ at 0.1 C for LNMO500, LNMO600, and LNMO700, respectively, with well-defined ${\mathrm{Ni}}^{2+}{\mathrm{/Ni}}^{3+}$ and ${\mathrm{Ni}}^{3+}{\mathrm{/Ni}}^{4+}$ redox peaks at 4.7 and 4.8 V. DFT calculations independently predict a voltage plateau at ∼4.7 V for $0.2\le x\le 1$, in agreement with the experimental profiles. These findings establish MOD as a viable, vacuum-free route to the synthesis of nanostructured LNMO cathodes.