In the present work, a TiO₂/zeolite photocatalyst was synthesized by dispersing TiO₂ nanoparticles obtained through the sol-gel method onto the surface of natural zeolite derived from ignimbrite residue. The zeolite was obtained from an ignimbrite rubble treatment collected from a quarry in Arequipa City, Peru. The research focused on the effect of zeolite on the TiO₂ nanoparticles. The synthesized photocatalysts were characterized using various techniques, including field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDS), X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), and Brunauer–Emmett–Teller surface area analysis (BET). The results revealed that the TiO₂/zeolite samples displayed high crystallinity, with TiO₂ being present in three phases and zeolite being present in the analcime phase. Furthermore, these samples exhibited a band gap of 3.14 eV and a high surface area compared to that of bare TiO₂. Finally, the photocatalytic activity of the TiO₂/zeolite composite obtained was evaluated toward the decomposition of 10 ppm and 20 ppm of methyl orange (MO) dye. The TiO₂/zeolite samples demonstrated improved photocatalytic activity compared to that of pristine TiO₂ under the same experimental conditions. This enhancement is primarily attributed to the increased specific surface area of the TiO₂/zeolite samples, making them promising materials for future efficient and sustainable photocatalytic applications.

The persistence of azo dyes in industrial effluents poses significant environmental risks; therefore, there is a need to develop effective adsorbents. This study investigates the efficiency of a Cu₂O/CuO nanocomposite as an adsorbent for the removal of a model dye, methyl orange (MO), from aqueous solutions. The material was characterized by XRD, SEM and BET analyses, revealing a dominant Cu₂O phase (96 wt%) with CuO fractions, and an average particle size of ~18 nm paired with a specific surface area of 19.54 m² g⁻¹. FTIR and TOC assays revealed the adsorption and degradation of MO by action of the nanocomposite. Operational parameters such as adsorbent dosage, initial dye concentration, pH, and the point of zero charge (PZC) were investigated. Under the optimized conditions, the nanocomposite achieved a dye removal efficiency of 97.0%. The kinetic results showed a strong correlation with the pseudo-second-order model. Furthermore, isotherm analysis revealed that the adsorption process is best described by the Langmuir–Freundlich model, demonstrating an outstanding maximum theoretical adsorption capacity (q_max) of 254.76 mg g⁻¹, which closely aligns with the experimental value (249.48 mg g⁻¹). The findings demonstrated that the synthesized Cu₂O/CuO nanocomposite acts as an efficient and promising adsorbent for the remediation of dye-contaminated waters.

The present work aims to synthesize and characterize zinc oxide nanoparticles (ZnO-NP’s) to apply them as nano-priming of purple maize (Zea Mays L.) seeds. The ZnO NP’s were obtained by biosynthesis using leaf extract of Vasconcellea Pubescens. To determine the optimal process conditions, a full 23 factorial design was implemented, whose statistical analysis identified reaction temperature and precursor concentration as the most significant variables. Specifically, the combination of 20 °C and 0.05 mol L-1 favored the attainment of the smallest crystallite size, validating the efficiency of the proposed experimental model. Under the identified optimal conditions, comprehensive characterization by XRD, SEM, EDS, and TEM confirmed the obtainment of ZnO NP’s of approximately 3 nm, characterized by high crystalline purity and biocompatibility. Additionally, ATR-FTIR analysis identified that the phenolic and glycosidic functional groups of the extract act as the main reducing and stabilizing agents in the synthesis. The bionanotechnological potential of these nanostructures was evaluated through nano-priming of purple maize (Zea mays L.) seeds using concentrations of 50, 100, and 200 mg L-1. In comparison with the control group, the 100 mg L-1 dose significantly optimized the germination percentage, radicle and seedling length, and vigor index. As this is the first report on the use of Vasconcellea pubescens for the synthesis of ZnO-NP’s, this study highlights the potential of functional bionanomaterials and eco-friendly processes to strengthen the productivity of Peruvian agriculture.