https://repositorio.ifg.edu.br/handle/prefix/80 2026-08-19T13:05:34Z 2026-08-19T13:05:34Z Castro, Aline Souza https://repositorio.ifg.edu.br/handle/prefix/2440 2025-10-09T16:55:33Z 2025-08-30T00:00:00Z

Título: Avaliação fotocatalítica do TiO2 Funcionalizados com Nanopartículas Metálicas Autor(es): Castro, Aline Souza Primeiro Orientador: Santos, Lidiaine Maria dos Abstract: The present study aimed to evaluate the photocatalytic activity of TiO₂ functionalized with metal nanoparticles for the degradation of the Ponceau 4R dye. To this end, TiO₂ was synthesized by the sol-gel method, followed by hydrothermal treatment to enhance its properties. The incorporation of metal nanoparticles was performed by photodeposition. The materials were characterized by thermal analysis, Fourier transform infrared pectroscopy, and X-ray diffraction. X-ray diffraction (XRD) analysis confirmed that the anatase phase crystal structure of TiO₂ was maintained in all samples, and thermal analysis indicated that the material is thermally stable up to 600 °C. The experimental photodegradation results of the Ponceau 4R dye demonstrated that silver-functionalized TiO₂ performed better, achieving a decolorization efficiency of 83% in 120 minutes, superior to both pure TiO₂ (64%) and copper-modified TiO₂ (54%). Silver's high efficiency is explained by its ability to capture electrons, preventing the recombination of electron-hole pairs and, consequently, increasing the production of oxidizing free radicals. Conversely, exchange with copper proved inefficient, inhibiting photocatalytic activity by acting as a recombination center for electrons and holes. Editor: Insitituto Federal de Educação, Ciência e Tecnologia de Goiás Tipo: Trabalho de Conclusão de Curso

2025-08-30T00:00:00Z Barreto, Mateus Silva https://repositorio.ifg.edu.br/handle/prefix/2427 2025-09-26T11:59:28Z 2025-08-30T00:00:00Z

Título: Células Solares de Perovskita: Uma Revisão Sistemática da Literatura Autor(es): Barreto, Mateus Silva Primeiro Orientador: Santos, Lidiaine Maria dos Abstract: Solar Cell as a Promising and Sustainable Emerging Technology.Solar Cells as a Promising and Sustainable Emerging Technology Perovskite solar cells (PSCs) stand out as a promising technology for clean energy generation, combining high efficiency (>26%), low cost, and application flexibility, such as in tandem and transparent devices. This study, based on 25 articles selected between 2015 and 2025 from Scopus, Web of Science, ScienceDirect, and Google Scholar, highlights that, although they show great potential, PSCs still face barriers related to environmental degradation, lead toxicity, and industrial scaling limitations. In this context, strategies such as advanced encapsulation, replacement of toxic elements, and hybrid architectures emerge as essential paths to their commercial viability. Editor: Insitituto Federal de Educação, Ciência e Tecnologia de Goiás Tipo: Trabalho de Conclusão de Curso

2025-08-30T00:00:00Z Teixeira, Bruno, de Ávila https://repositorio.ifg.edu.br/handle/prefix/2309 2025-06-10T21:26:47Z 2025-05-14T00:00:00Z

Título: Análise da viabilidade do uso do cloreto de sódio como conservante em detergentes: uma solução sustentável Autor(es): Teixeira, Bruno, de Ávila Primeiro Orientador: Santos, Lidiaine, Maria dos Abstract: Detergents are widely used in cleaning and differ from soaps in terms of chemical composition and manufacturing process, offering greater efficiency, especially in hard water. However, many conventional detergents contain non-biodegradable surfactants and synthetic preservatives, such as triclosan and isothiazolinones, which can harm the environment and pose health risks. Considering these impacts, this study evaluated the feasibility of using sodium chloride (NaCl) as a preservative in detergents, aiming to minimize environmental effects and protect consumer health while maintaining product quality and effectiveness. To achieve this, three formulations were developed with different combinations of raw materials, replacing synthetic preservatives with NaCl, which has low toxicity and antimicrobial properties due to its osmotic action. The samples were analyzed for appearance, density, and viscosity over time to verify the stability of the formulations. Microbiological tests were conducted to monitor fungal and bacterial growth using specific culture media and controlled incubation conditions. The results indicated that the formulations showed good stability and that NaCl was effective as a thickener and preservative, preserving product quality. The samples had higher viscosity than commercial detergents, providing a competitive advantage, although adjustments are needed to avoid flow difficulties. Cleaning efficiency was not directly tested but was considered satisfactory based on the selection of raw materials and the positive results of the stability and microbiological tests. The absence of microbial growth for four months confirmed the antimicrobial activity of NaCl. It was concluded that the use of NaCl as a preservative is a viable and sustainable alternative to replacing synthetic compounds in detergents, reducing environmental impact and health risks. However, antimicrobial efficacy was only proven in the short term, suggesting the need for further research to improve long-term preservation. The developed formulations demonstrated potential for local commercialization, with the possibility of regional or national expansion if future studies confirm greater durability. Editor: Insitituto Federal de Educação, Ciência e Tecnologia de Goiás Tipo: Trabalho de Conclusão de Curso

2025-05-14T00:00:00Z Silva Filho, Welton, Martins da https://repositorio.ifg.edu.br/handle/prefix/2271 2025-05-27T15:13:28Z 2025-03-24T00:00:00Z

Título: Avaliação de eficiência de fotocatalisadores à base de dióxido de titânio na degradação de formaldeído Autor(es): Silva Filho, Welton, Martins da Primeiro Orientador: Santos, Lidiaine, Maria dos Abstract: Formaldehyde, widely used in industries and consumer products, is a highly toxic and potentially carcinogenic substance associated with respiratory irritation, dermatitis, and environmental risks due to its persistence in aquatic ecosystems. Among Advanced Oxidation Processes (AOPs), photocatalysis, which uses light-activated photocatalysts, enables the degradation of persistent pollutants. A highly promising photocatalyst is titanium dioxide (TiO₂). Two TiO₂ samples were compared—one thermally treated in a muffle furnace (GM) and the other by a hydrothermal method (HT)—both synthesized via the sol-gel method. The samples were characterized by X-ray diffraction (XRD), diffuse reflectance spectroscopy, and specific surface area analysis (BET). The results showed that the hydrothermal treatment yielded a photocatalyst with a smaller crystallite size (51 Å) and a larger surface area (246.8 m²/g) compared to the muffle furnace treatment, which had a crystallite size of 179 Å and a surface area of 51.8 m²/g. Photocatalytic experiments demonstrated that the HT photocatalyst was more efficient, degrading 93% of formaldehyde in 120 minutes, while GM achieved 89% degradation in the same experimental time. The higher efficiency of the HT photocatalyst is attributed to its larger surface area, which favors the generation of free radicals. The hydrothermal treatment is more advantageous in terms of both efficiency and energy cost. Editor: Insitituto Federal de Educação, Ciência e Tecnologia de Goiás Tipo: Trabalho de Conclusão de Curso

2025-03-24T00:00:00Z