Departamento de Química, Universidade Federal de Lavras, CEP: 37200-000, Lavras, MG, Brasil.
Departamento de Química, Universidade Federal de Minas Gerais, CEP: 31270-901 99, Belo Horizonte, MG, Brasil.
Environ Sci Pollut Res Int. 2021 Aug;28(31):42093-42106. doi: 10.1007/s11356-021-13727-7. Epub 2021 Apr 1.
Water contamination is a common problem, especially considering dyes and drugs disposal. A possible and effective treatment method to remove these organic pollutants from water is photocatalytic reaction. This study aimed to improve the photocatalytic properties of TiO using iron oxides (Ti/Fe composite). Different magnetic photocatalysts based on commercial TiO were obtained with 30, 50, and 80% (wt./wt.) of TiO supported on maghemite. X-ray diffraction with Rietveld refinement confirms the presence of γ-FeO, α-FeO, anatase, and rutile, as well as the relative percentages of the phases present in each photocatalyst. The magnetic properties were certified by VSM and sedimentation kinetics in the presence of a magnetic field. Besides their magnetic properties, UV-vis DRS shows that the obtained photocatalysts presented lower bandgap values when compared with TiO. These factors allowed the materials to absorb radiation in the visible-light region and the separation from the reaction medium by the application of magnetic field. It was observed an enhancement of photodegradation reaction of methylene blue (MB) and paracetamol (PC). For example, when the content of TiO increased from 30 to 80% (wt./wt.), the efficiency increased from 58 to 99% (for MB) and 39 for 80% (for PC) under UV (λ = 254 nm). The reactions carried out with solar radiation showed 56 to 95% efficiency to discolor MB. In addition, the results of sedimentation kinetics and characterization confirmed the goals of the synthesis.
水污染是一个常见的问题，特别是考虑到染料和药物的处理。一种可能且有效的处理方法是光催化反应，用于从水中去除这些有机污染物。本研究旨在通过氧化铁（Ti/Fe 复合材料）来提高 TiO 的光催化性能。通过在商业 TiO 上负载 30、50 和 80%（wt./wt.）的 TiO ，获得了不同的磁性光催化剂，得到了基于商业 TiO 的不同磁性光催化剂。X 射线衍射与 Rietveld 精修证实了 γ-FeO、α-FeO、锐钛矿和金红石的存在，以及每种光催化剂中存在的各相的相对百分比。磁性通过 VSM 和磁场存在下的沉降动力学得到证实。除了磁性之外，UV-vis DRS 表明，与 TiO 相比，所获得的光催化剂具有更低的带隙值。这些因素允许材料在可见光区域吸收辐射，并通过施加磁场从反应介质中分离出来。观察到亚甲基蓝（MB）和扑热息痛（PC）的光降解反应增强。例如，当 TiO 的含量从 30%增加到 80%（wt./wt.）时，在 UV（λ=254nm）下，效率从 58%提高到 99%（用于 MB）和 80%（用于 PC）。在太阳辐射下进行的反应对 MB 的脱色效率为 56%至 95%。此外，沉降动力学和表征的结果证实了合成的目标。
