Revealing the crystal phases of primary particles formed during the coprecipitation of iron oxides
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作者
Mao, Yu; Zhang, Zuoheng; Zhan, Hongfeng; Sun, Jianfei; Li, Yan; Su, Zhenhuang; Chen, Yonghua; Gao, Xingyu; Huang, Xiao; Gu, Ning
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刊物名称
CHEMICAL COMMUNICATIONS
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年、卷、文献号
2022, 58, 1359-7345
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关键词
Mao, Yu; Zhang, Zuoheng; Zhan, Hongfeng; Sun, Jianfei; Li, Yan; Su, Zhenhuang; Chen, Yonghua; Gao, Xingyu; Huang, Xiao; Gu, Ning
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摘要
The mechanistic investigation of the coprecipitation formation of iron oxides has been a long-standing challenge due to the rapid reaction kinetics and high complexity of iron hydrolysis reactions. Although a few studies have suggested that the coprecipitation of iron oxide nanoparticles follows a non-classic route through inter-particle attachment, the compositions of the primary particles remain undetermined. Herein, by using a specially designed gas/liquid mixed phase fluidic reactor we controlled the reaction time from 3 s to over 5 min, and successfully identified the concentration of different intermediate phases as a function of time. We suggest that the initial Fe3+ ions are hydrolyzed under the alkaline condition to give Fe(OH)(3), which then rapidly dehydrates to yield alpha-FeOOH. In the presence of Fe2+ ions, which could also act as the catalyst, alpha-FeOOH finally transforms to Fe3O4.
