Sunlight-Induced Interfacial Electron Transfer of Ferrihydrite under Oxic Conditions: Mineral Transformation and Redox Active Species Production
العنوان: | Sunlight-Induced Interfacial Electron Transfer of Ferrihydrite under Oxic Conditions: Mineral Transformation and Redox Active Species Production |
---|---|
المؤلفون: | Zhipeng Shu, Zezhen Pan, Xingxing Wang, Haohua He, Shuwen Yan, Xiuping Zhu, Weihua Song, Zimeng Wang |
المصدر: | Environmental Science & Technology. 56:14188-14197 |
بيانات النشر: | American Chemical Society (ACS), 2022. |
سنة النشر: | 2022 |
مصطلحات موضوعية: | Minerals, Nitrates, Hydroxyl Radical, Sulfates, Iron, Water, Electrons, General Chemistry, Oxidants, Ferric Compounds, Oxygen, Chlorides, Superoxides, Sunlight, Environmental Chemistry, Ferrous Compounds, Oxidation-Reduction |
الوصف: | Fe(II)-catalyzed ferrihydrite transformation under anoxic conditions has been intensively studied, while such mechanisms are insufficient to be applied in oxic environments with depleted Fe(II). Here, we investigated expanded pathways of sunlight-driven ferrihydrite transformation in the presence of dissolved oxygen, without initial addition of dissolved Fe(II). We found that sunlight significantly facilitated the transformation of ferrihydrite to goethite compared to that under dark conditions. Redox active species (hole-electron pairs, reactive radicals, and Fe(II)) were produced from the ferrihydrite interface via the photoinduced electron transfer processes. Experiments with systematically varied wet chemistry conditions probed the relative contributions of three pathways for the production of hydroxyl radicals: (1) oxidation of water (5.0%); (2) reduction of dissolved oxygen (40.9%); and (3) photolysis of Fe(III)-hydroxyl complexes (54.1%). Results also showed superoxide radicals as the main oxidant for Fe(II) reoxidation under acidic conditions, thus promoting the ferrihydrite transformation. The presence of inorganic ions (chloride, sulfate, and nitrate) did not only affect the hydrolysis and precipitation of Fe(III) but also the generation of radicals via photoinduced charge transfer reactions. The involvement of redox active species and the accompanying mineral transformations would exert a profound effect on the fate of multivalent elements and organic contaminants in aquatic environments. |
تدمد: | 1520-5851 0013-936X |
URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f56000fdc5bf703a982528e3e40e156f https://doi.org/10.1021/acs.est.2c04594 |
حقوق: | CLOSED |
رقم الأكسشن: | edsair.doi.dedup.....f56000fdc5bf703a982528e3e40e156f |
قاعدة البيانات: | OpenAIRE |
تدمد: | 15205851 0013936X |
---|