Hybrid solar cells show an increasing number in researches due to its low cost and easy of production. They are composed by and organic material and a semiconductor oxide. The aim of this paper was to synthesis and characterize zinc oxide by coprecipitation and apply it in a hybrid solar cell that uses a P3HT/P3OT copolymer as charge carrier. The cell was assembled in "sandwich" form using FTO/ZnO/P3HT-P3OT as work electrode, (Pt/FTO) as conter electrode and I/I-3 redox couple as electrolyte. Through the X-ray diffractogram the formation of a single ZnO wutzite hexagonal phase was observed. The morphology obtained for the oxide was spherical. The results of photochronoamperometry showed current density values of jP3HT/P3OT =0.55 mA.cm^-2 for the cell in the presence of the copolymer and the curve jxV showed an efficiency of 0.16% for the studied cell, demonstrating that the polymer was a satisfactory sensitizer.

Ethylparaben (EtP) is an emerging pollutant that is widely found in the environment, particularly in agricultural landscapes. With the extensive contamination of agricultural soils and irrigation waters, there is a rising concern about their potential impact on crop yields. To provide some of the first evidence that EtP may be more than just an agricultural contaminant, but a potential pollutant, we evaluated the systemic toxicities and cellular responses triggered by EtP in seed roots of Daucus carota, Lycopersicum esculentum, and Cucumis sativus, and in bulb roots of Allium cepa, at environmentally relevant concentrations of 1, 10, 100, and 1000 ng·L⁻¹. The seeds and bulbs remained in contact with the concentrations for 7 days. Distilled water and Tween 80 at 1000 ng·L⁻¹ were used as negative controls. The results were subjected to Kruskal–Wallis analysis of variance followed by Dunn’s test (p ≤ 0.05). In all plants, all concentrations significantly altered the activity of catalase, ascorbate peroxidase, guaiacol peroxidase, and superoxide dismutase. In carrot (10, 100, and 1000 ng·L⁻¹), tomato (1000 ng·L⁻¹), and cucumber (all concentrations), such concentrations caused lipid peroxidation, leading to the accumulation of hydrogen peroxide, as well as hydroxyl and superoxide radicals in the cells. These oxidants caused a delay in the progression of the cell cycle and alterations to the mitotic spindle in the root meristems, significantly inhibiting root growth in the plants evaluated. Recurrent contamination with EtP can potentially harm soil quality, posing a risk to both agricultural productivity and the environment.

The development of dye-sensitized solar cells (DSSCs) has gained prominence as an economical alternative for photovoltaic energy conversion. This work investigates the synthesis of niobium pentoxide (Nb₂O₅) by the Pechini method, followed by calcination at different temperatures (500 °C, 600 °C and 700 °C) to evaluate its structural, morphological, and electrochemical properties as a photoanode material in DSSCs. SEM and XRD analyses revealed that calcination at 600 °C produced a material with optimized particle size (642.17 ± 37 nm) and adequate crystalline structure, favoring dye adsorption and electronic transport. Electrochemical characterization, including open-circuit potential and impedance spectroscopy, indicated that the sample at 600 °C presented superior photovoltaic performance, achieving a power conversion efficiency of 1.39% and electron lifetime equal to 0.159 s. These findings suggest that Nb₂O₅, under controlled calcination conditions, may act as a promising alternative to TiO₂ substitution in DSSC applications.