Photocatalytic Analysis of Titanium Semiconductors Anodized in H ₃ po ₄ , Hf and <i>Psidium guajava</i> -Based Electrolyte

Titanium is a versatile material that can be used both as a semiconductor in heterogeneous photocatalysis and in the medical field, mainly to produce implants aimed at restoring, replacing, and correcting biological structures with poor osseointegration performance. This versatility is directly related to its unique properties, such as low toxicity, chemical stability, ability to absorb UV light, durability, stability at different pHs, and photosensitivity. Therefore, this study aims to compare titanium anodizing in <i>Psidium guajava</i> using an anodizing bench with the industrial process. For this purpose, samples anodized in <i>Psidium guajava</i> and anodized by the industrial process (H₃PO4 or H₃PO₄ + HF) were compared regarding morphology, roughness, color, electrochemical corrosion tests, and Raman spectroscopy. Additionally, heterogeneous photocatalysis tests were also performed to assess the photocatalytic activity of TiO₂ in the degradation of methylene blue dye. It was found that the samples anodized with the <i>Psidium guajava</i> electrolyte showed high photoactivity (99%) in the degradation of methylene blue, in addition to a performance similar to that of H₃PO₄ + HF and better than that of H₃PO₄. This can be attributed to the presence of phenolic compounds such as quercetin and indicates that <i>Psidium guajava</i> anodizing is an efficient and sustainable alternative to the industrial process.