Silver nanoparticles (AgNPs) have aroused great interest for applications as fungicides in agriculture. This study reports the synthesis of AgNPs by green chemistry using silver nitrate (AgNO₃) as the precursor agent and a coriander leaf extract as the reducing agent and surfactant. The evaluation of their antifungal properties was carried out when placed in contact with Fusarium solani and Rhizopus stolonifer phytopathogens. The extract and AgNP characterizations were performed using UV–Vis spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), dynamic light scattering (DLS) and scanning electron microscopy (SEM). The evaluation of antifungal properties was carried out by exposing the phytopathogens to different concentrations of AgNPs in PDA (Potato Dextrose Agar). It was found that it was possible to identify the presence of flavones and flavonoids in the extract, compounds that were also involved in the synthesis process of AgNPs. In addition, the UV–Vis analysis of the obtained AgNPs by green chemistry showed resonance peaks at around 428 nm. Furthermore, a high distribution of AgNP sizes, with high concentrations of below 100 nm, was identified, according to DLS measurements. Using SEM images, the information provided by DLS was confirmed, and a crystallite size of 29.24 nm was determined with the help of XRD measurements. Finally, when exposing the phytopathogens to the action of AgNPs, it was concluded that, at a concentration of 1 mg/mL AgNPs, their growth was totally inhibited.

This study shows the energy optimization and stabilization in the time of solutions composed of H₂O + TX-100 + Multi-Wall Carbon Nanotubes (MWCNTs), used to improve the mechanical properties of Portland cement pastes. For developing this research, sonication energies at 90, 190, 290, 340, 390, 440, 490 and 590 J/g are applied to a colloidal substance (MWCNTs/TX-100 + H₂O) with a molarity of 10 mM. Raman spectroscopy analyses showed that, for energies greater than 440 J/g, there are ruptures and fragmentation of the MWCNTs; meanwhile at energies below 390 J/g, better dispersions are obtained. The stability of the dispersion over time was evaluated over 13 weeks using UV-vis spectroscopy and Zeta Potential. With the most relevant data collected, sonication energies of 190, 390 and 490 J/g, at 10 mM were selected at the first and the fourth week of storage to obtain Portland cement specimens. Finally, we found an improvement of the mechanical properties of the samples built with Portland cement and solutions stored for one and four weeks; it can be concluded that the MWCNTs improved the hydration period.

Nowadays, nanomaterials in cement pastes are among the most important topics in the cement industry because they can be used for several applications. For this reason, this work presents a study about the influence of changing the molarity of dispersed multiple wall carbon nanotubes (MWCNTs) and varying the number of storage days on the mechanical properties of the cement paste. To achieve this objective, dispersions of 0.35% MWCNTs, varying the molarity of the surfactant as 10 mM, 20 mM, 40 mM, 60 mM, 80 mM, and 100 mM, were performed. The mixture of materials was developed using the sonication process; furthermore, materials were analyzed using UV-Vis, Z-potential, and Raman spectroscopy techniques. Materials with a molarity of 10 mM exhibited the best results, allowing them to also be stored for four weeks. Regarding the mechanical properties, an increase in the elastic modulus was observed when MWCNTs were included in the cement paste for all storage times. The elastic modulus and the maximum stress increased as the storage time increased.

The objective of this study is to map, describe, and identify “water treatment using catalysts and/or nanomaterials” and their derivable aspects. A comprehensive search was conducted in academic databases such as WoS and Scopus, following the PRISMA methodology, to identify relevant studies published between 2010 and 2024. Inclusion and exclusion criteria were applied to select articles that address both experimental and theoretical aspects of photocatalysis in wastewater treatment. The methodology is developed through exploratory data analysis and the use of the Tree of Science algorithm. The first results indicate the roots, in which it is possible to gain knowledge of the environment for the implementation of a photoreactor it uses as a photocatalyst agent. A total of 94 relevant articles were identified. The results show that most studies focus on the degradation of organic pollutants using TiO₂ as a photocatalyst. Additionally, there has been a significant increase in the number of publications and citations in recent years, indicating growing interest in this field. Then, in the trunk, some more solid ideas in terms of basic concepts, techniques and possible variations for the application of knowledge and development of future research related to the initial topic are indicated. Finally, through the leaves, new modifications and combinations of the photocatalytic materials are obtained, in search of improving their performance in terms of reduction in water contaminants. From the above, centrality in photocatalysis is identified as an alternative for water remediation using different photocatalysts. It is concluded that the total citation network contains, within the most important nodes, articles of high interest in the community, such as those authored by Zhang, Xiaofei; Nezamzadeh-Ejhieh, Alireza; or Li, Jingyi, from countries in the Middle East and the Asian continent, justified not only by the research capabilities of these countries, but also by the needs and problems that these regions face in terms of water scarcity. Future work indicates the need for and interest in improving various characteristics such as photocatalytic performance, the number of cycles that the material supports, and its reduction capacity in the presence of high concentrations of contaminants, with the intention of maximizing the benefits of its applicability in water treatment.

In this study, we research the innovative application of multi-walled carbon nanotubes (MWCNTs) as corrosion inhibitors in Portland cement embedded steel. The physicochemical properties of the dispersion solutions were evaluated, varying the storage time, to analyze their effect on corrosion resistance. Using a dispersion energy of 440 J/g and a constant molarity of 10 mM, stable dispersions were achieved for up to 3 weeks. These dispersions were characterized using Raman spectroscopy, UV-Vis spectroscopy and Zeta potential spectroscopy to assess the stability and structural damage of the MWCNTs. These results show that the addition of MWCNTs not only reduces the porosity of the cement matrix, but also forms an effective barrier against chloride ion intrusion, protecting the reinforcing steel. This approach stands out for combining improved mechanical properties and significant corrosion resistance, representing a promising innovation in the development of more durable construction materials.