The search for novel materials and the development of improved processes for water purification have attracted the interest of researchers worldwide and the use of titanium dioxide in photocatalytic processes for the degradation of organic pollutants contained in water has been one of the benchmarks. Compared to crystalline titanium dioxide (cTiO₂), the amorphous material has the advantages of having a higher adsorption capacity and being easier to dope with metal and non-metal elements. In this work, we take advantage of these two features to improve its photocatalytic properties in the degradation of Rhodamine B. The structural characterization by XRD analysis gives evidence of its amorphous nature and the SEM micrographs portray the disc morphology of 300 nm in diameter with heterogeneous grain boundaries. The degradation of Rhodamine B tests with the amorphous TiO₂ using visible light confirm its improved catalytic activity compared to that of a commercial product, Degussa P25, which is a well-known crystalline material.

In this work, a novel route is discussed to produce in one step ZnO/Burkeite powders by the modified solution combustion method. The ZnO particles enhance the photocatalytic activity in the degradation of Rhodamine B, in which Burkeite mineral acts as a support due to the pH-dependent morphology of the particle aggregates of the as-synthesized powders. The X-ray diffraction (XRD) characterization shows the presence of a heterostructure: ZnO/Burkeite. The Scanning Electron Microscopy (SEM) image shows a morphological dependence with the pH of the solution used for the synthesis. The results show that the system with the highest degradation (92.4%) corresponds to the case in which ZnO/Burkeite heterostructure was synthesized with a pH 11.

This work proposes a new mathematical model for reproducing desertification and vegetation patterns. The model consists of two nonlinear partial differential equations. One of them describes the Spatio-temporal dynamic of vegetation in an analogous way to Lefever’s model, while the precipitation dynamic is given by one equation of Hardenberg’s model. The model’s equations are solved using a numerical-functional difference method for the Spatio-temporal terms. The numerical results reproduce various bi-dimensional (2D) patterns observed in water-limited regions, including stripes, spots, hollows, and labyrinths. 2D patterns with these morphologies are characterized by their Fourier spectra and quantified their dimension fractal. The numerical solutions of the model also predict transitions from bare soil at low precipitation to homogeneous vegetation at high rainfall. These results reveal an underlying mechanism for the local desertification process and the vegetation self-organization. The broad context of matter order-disorder transitions. The proposed model even reproduces the desertification patterns for local instabilities of the hydrodynamic type beyond the instability induced by diffusion.

In this work, the electronic, thermochemical, and vibrational characterization of the drug delivery system formed by clusters of selenium (Se₆ allotrope) and 5-fluorouracil (5-FU) are studied, based on density functional theory (DFT) calculations. Computational calculations were performed using the B3LYP functional and the 6-31G(d,p) base set, considering an aqueous medium through the CPCM solvation model. We propose evaluating two different interaction modes based on experimental observations: Se–H(N) (through the amino groups of 5-FU) and Se–O(C) (through the carbonyl oxygen of 5-FU). All complexes proved to be energetically stable, exhibiting chemisorption as their adsorption process. Analysis of adsorption energy and thermodynamic parameters indicates that both interaction pathways are equally viable, which agrees with previous experimental findings. The theoretical FT-IR spectra of these complexes also coincide with the experimental results. Furthermore, global molecular descriptors show that the stability of the selenium carrier is not affected by post-functionalization, which is desirable for more controlled drug delivery systems.