Effective photodegradation of tetracycline by narrow-energy band gap photocatalysts La2-xSrxNiMnO6 (x = 0, 0.05, 0.10, and 0.125)
Effective photodegradation of tetracycline by narrow-energy band gap photocatalysts La2-xSrxNiMnO6 (x = 0, 0.05, 0.10, and 0.125)
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DOI：
10.1016/j.jallcom.2019.07.233
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发表时间：
2019-10
影响因子：
6.2
通讯作者：
Xiaoyan Yu;Junfeng He;Yimin Zhang;Jiamin Hu;Fuming Chen;Yinzhen Wang;Guannan He;Junming Liu-
中科院分区：
文献类型：
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作者：
Xiaoyan Yu;Junfeng He;Yimin Zhang;Jiamin Hu;Fuming Chen;Yinzhen Wang;Guannan He;Junming Liu-
由于四环素对人体健康的不良影响，它应该被通常由光催化剂在紫外线辐射下产生的活性物质完全降解。这种辐射大约只占太阳光能量的5%。一般来说，由于光的光谱宽，光催化剂在光照射下获得活性物质是具有挑战性的。为了解决这一问题，设计并通过固相反应制备了具有高电位价带边（EVB）、丰富氧空位（v -s）和窄能带隙（Eg）的新型光催化剂La2-xSrxNiMnO6（x = 0,0.05,0.10和0.125，分别表示为LNMO、LSNMO005、LSNMO010和LSNMO0125）。用多种技术对合成的粉末进行了表征。Sr2+的掺入显著提高了LNMO的evb，而sov -s略有增加。LSNMO010光生载流子的evb最高，mov -s最大，寿命最长，传输速度最快。结果表明，LSNMO010能在240 min内有效降解TC。在LSNMO010存在下，TC也可以在100 °C、90 min条件下进行热催化降解。然而，在没有LSNMO010的情况下，仅通过光解或热解都不能有效地降解TC。结果表明，光生空穴（h+-s）和羟基自由基（•OH）在TC的光降解过程中起主导作用。总有机碳（TOC）测定结果表明，直接光解作用仅去除18.28%的TOC，约83.90%的TOC被LSNMO010矿化。这项工作的结果表明，引入掺杂剂来增加ovand以获得高电位的evbin双钙钛矿可能是设计一类能有效降解TC的窄型egp光催化剂的新方法。
Owing to the adverse effects of tetracycline (TC) on human health, it should be completely degraded by the active species that are usually generated by photocatalysts under ultraviolet (UV) radiation. Such radiation which accounts for about only 5% energy of the sunlight. In general, obtaining the active species of the photocatalysts upon irradiation with light is challenging because of the wide spectrum of light. To address this, novel photocatalysts, La2-xSrxNiMnO6(x = 0, 0.05, 0.10, and 0.125, denoted by LNMO, LSNMO005, LSNMO010, and LSNMO0125, respectively), with high-potential valence band edge (EVB), abundant oxygen vacancies (OV-s), and narrow-energy band gap (Eg) were designed and prepared via a solid-state reaction. The synthesized powders were characterized by several techniques. Sr2+doping was found to significantly raise theEVBof LNMO and slightly increase itsOV-s. The highestEVB, maximumOV-s, longest lifetime, and fastest transferring speed of the photogenerated carriers were observed for LSNMO010. It was found that LSNMO010 could effectively photodegrade TC in 240 min. TC could also undergo thermocatalytic degradation at 100 °C in 90 min in the presence of LSNMO010. However, TC could not be effectively degraded either by photolysis or thermolysis alone, in the absence of LSNMO010. It was concluded that the photogenerated holes (h+-s) and hydroxyl radicals (•OH) played dominant roles in the photodegradation of TC. Measurement of the total organic carbon (TOC) revealed that only 18.28% TOC was removed by direct photolysis, and about 83.90% TOC was mineralised by LSNMO010. The outcomes of this work suggest that introduction of dopants to increaseOVand to obtain high-potentialEVBin double perovskites could be a novel methodology for designing a class of narrow-Egphotocatalysts that can effectively degrade TC.