531-53-3Relevant articles and documents
A facile synthesis of Mn3O4/Fe3O 4 superparamagnetic nanocomposites by chemical precipitation: Characterization and application in dye degradation
Silva, Gabriela C.,Ciminelli, Virginia S.T.,Ferreira, Angela M.,Pissolati, Nathalia C.,Paiva, Paulo Renato P.,López, Jorge L.
, p. 544 - 551 (2014)
Degradation of methylene blue (MB) is investigated using Mn 3O4 as an oxidant. Discrete Mn3O4 particles and Mn3O4/Fe3O4 nanocomposites are synthesized via coprecipitation by using air as an oxidant in the absence and presence of previously synthesized magnetite nanoparticles, respectively. Characterization results show that superparamagnetic magnetite nanoparticles of ～10 nm were synthesized. The Mn3O4 synthesis in the presence of these magnetite nanoparticles favors the formation of a pure, highly ordered Mn3O4/Fe3O 4 superparamagnetic nanocomposite, which can be separated by an external magnetic field. This nanocomposite is applied to the oxidative decolorization of methylene blue (MB) and is capable of catalyzing the complete N-demethylation of MB, forming thionine as the final product and removing 93% of the dye in approximately 1 h.
HPLC-MS and UV–Visible Coupled Analysis of Methylene Blue Photodegradation by Hydrothermally Grown ZnO Nanowires
Martin, Nathan,Leprince-Wang, Yamin
, (2021/10/27)
Photocatalysis is an efficient and promising method to purify water. Numerous studies have been dedicated to demonstrate its efficiency on several hazardous compounds, derived from various industries. However, even if the degradation of such products has been extensively studied, obtaining information on their photodegradation pathway is still challenging, leading to concerns about the innocuousness of the treated water. In this study, the authors use ZnO nanowires (ZnO NWs), to photodegrade a solution of the commonly used organic dye methylene blue (MB) under ultraviolet (UV) irradiation, followed simultaneously by UV-visible (UV-vis) spectrometry and high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). Combining these two methods real-time information on the photodegradation efficiency and degradation mechanism are given. The HPLC-MS analysis allows us to confidently identify three reaction intermediates of the MB degradation: Azure A, B and C, as well as spot three other compounds, with uncertain formulas, leading to the presented hypothesis on the beginning of the MB degradation pathway. While the UV-visible analysis shows a total degradation of MB after 2 h of photodegradation, the HPLC-MS analysis indicates that some MB remain in the solution. Its quantity is calculated to be 14 μg L?1, which is harmless to humans.
