Binary sulfides were deposited by sequential thermal evaporation with the stacking order glass/CuS/SnS/ZnS and subsequently subjected to a sulfurization-crystallization process, considering two thermal treatment time intervals, 5 and 20 min. The objective of implementing different annealing durations was to identify the best conditions to form CZTS films in the pure kesterite phase. After being subjected to the annealing, the films show structural characteristics of the kesterite phase. However, XRD data showed that prolonged annealing causes degradation of the kesterite phase, leading to the formation of traces of CuS and Cu₅Sn₂S₇. The films annealed for shorter duration, in this case 5 min, present a denser and more uniform surface morphology, better degree of preferential orientation, small Urbach energy of 0.302 eV, and higher photosensitivity. The band gap of the films was 1.46 eV and 1.53 eV for annealing durations 5 and 20 min, respectively. Graphical abstract

In this study, the catalytic potential of peroxidase enzymes obtained from soybean industrial residues was investigated for the decolorization of the azo dye Direct Blue 2 (DB2) in textile wastewater. Peroxidase fractions (15 ± 5 U/L) were extracted and partially purified by ion-exchange chromatography and applied to a pilot-scale effluent, achieving DB2 degradation rates of 1.48 mg/L·h in the presence of chemical additives. High-performance liquid chromatography confirmed dye removal and detected benzidine (1 mg/L) as a degradation byproduct. Acute toxicity tests using Vibrio fischeri showed minimal variation, with values of 8 TU for untreated wastewater and 7.94 TU after enzymatic treatment. A subsequent Fenton process was implemented as a polishing step, achieving up to 90% decolorization, a 30% reduction in organic matter, and complete elimination of toxicity at an FeSO₄/H₂O₂ ratio of 1:2.4. The results demonstrate a sustainable strategy for pre-treating textile effluents containing azo dyes through the enzyme-based valorization of agro-industrial residues.

En este trabajo se analizó la importancia del pH en un proceso de fotocatálisis al igual que se determinó el pH con el cual se obtiene mayor degradación del contaminante. Los resultados muestran que los contaminantes textiles azul de metileno y rodamina B con una concentración de 10ppm con un pH elevado obtienen mayor degradación esto debido a que al cambiar el pH con una solución de hidróxido de sodio con una concentración de 2M esta libera iones de hidroxilo los cuales pueden absorber hidrogeno (H+), lo que hace que la carga superficial y el tamaño de la banda del óxido de zinc se vean influenciados al igual que la carga del contaminante textil y al cambiar el tamaño de la banda se necesita menor energía para realizar la actividad electrón- hueco por lo que tiene mayor velocidad para la remoción del contaminante.