Enhanced photocatalytic degradation of organic contaminants over CaFe2O4 under visible LED light irradiation mediated by peroxymonosulfate
Enhanced photocatalytic degradation of organic contaminants over CaFe2O4 under visible LED light irradiation mediated by peroxymonosulfate
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DOI：
10.1016/j.jmst.2020.05.057
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发表时间：
2021-01-30
影响因子：
10.9
通讯作者：
Zhou, Kun
中科院分区：
文献类型：
--
作者：
Guo, Sheng;Yang, Zhixiong;Zhou, Kun
本文提出了一种简单的溶胶-凝胶法制备CaFe 2 O 4，用于在LED光照射下降解各种有机污染物（罗丹明B（RhB）、盐酸四环素、腐殖酸和亚甲基橙子）。结果表明，煅烧温度对CaFe 2 O 4的PMS活化性能有显著影响，在800 ℃煅烧得到的CaFe 2 O 4 -800样品对RhB的降解效果最好，远高于Fez 03 - 800样品。这可以归因于PMS对光生电子（e（-））和空穴（h（+））的有效分离，瞬态光电流响应和光致发光测量验证了这一点。密度泛函理论计算结果表明，CaFe 2 O 4 -800的价带具有较高的载流子浓度和较弱的电子局域化，有利于PMS的激活。自由基清除结果证实，H（+）和O-2（中心点-）是主要的反应物种。此外，CaFe 2 O 4 -800不仅在8次循环运行中表现出稳定的性能，铁浸出可忽略不计，而且在自然水和阳光下表现出优异的降解效率。最后，提出了CaFe（2）O（4）-800/PMS/LED体系降解RhB的机理和途径。这项工作提出了巨大的前景的CaFe 2 O 4作为一个环境友好的光催化剂激活PMS。(C)2020由Elsevier Ltd代表Journal of Materials Science & Technology编辑部出版。
A simple sol-gel approach is proposed herein to fabricate CaFe2O4 for the degradation of various organic pollutants (rhodamine B (RhB), tetracycline hydrochloride, humic acid, and methylene orange) under LED light irradiation mediated by peroxymonosulfate (PMS). The results indicate that the calcination temperature can significantly influence the performance of CaFe2O4 for PMS activation, and the CaFe2 04 sample obtained at 800 degrees C (CaFe2O4-800) exhibits the best efficiency in degrading RhB, which is much higher than that of Fez 03 -800. This can be attributed to the efficient separation of photogenerated electrons (e(-)) and holes (h(+)) by PMS, which is validated by transient photocurrent response and photoluminescence measurements. Results from density functional theory calculations indicate that the valence band of CaFe2O4-800 exhibits a high concentration of carriers and weak localization of electrons, which are favorable for PMS activation. Radical scavenging results confirm that h(+) and O-2(center dot-) are the dominant reactive species. Moreover, CaFe2O4-800 not only demonstrated a stable performance during eight cycling runs with negligible iron leaching but also exhibited excellent degradation efficiency under natural water and sunlight. Finally, the mechanism and pathway of RhB degradation by theCaFe(2)O(4)-800/PMS/LED system are also proposed. This work presents the enormous prospect of CaFe2O4 as an environmentally benign photocatalyst for PMS activation. (C) 2020 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.