Enhanced activation of peroxymonosulfate by Sr-doped LaFeO3 perovskite for Orange I degradation in the water
Enhanced activation of peroxymonosulfate by Sr-doped LaFeO3 perovskite for Orange I degradation in the water
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DOI：
10.1016/j.seppur.2020.117838
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发表时间：
2020-10
影响因子：
8.6
通讯作者：
Ying Zhao;Bin Huang;Hongze An;Guojun Dong;Jing Feng;Tong Wei;Yueming Ren;Jun Ma
中科院分区：
文献类型：
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作者：
Ying Zhao;Bin Huang;Hongze An;Guojun Dong;Jing Feng;Tong Wei;Yueming Ren;Jun Ma
在非均相催化中，钙钛矿的a位掺杂被认为是一种同时提高催化性能和限制金属释放的有效方法。本文合成了多种锶掺杂的lafeo3钙钛矿（La1-xSrxFeO3-δ），并对其作为非均相催化剂活化过氧单硫酸盐（PMS）降解水中的橙I （OI）进行了评价。其中，La0.6Sr0.4FeO3-δ(LSFO-40)的催化活性显著提高，常数为0.0411 min−1，是LaFeO3（0.0142 min−1）的3倍左右。锶掺杂后，稳定性好，金属浸出少。这种增强主要是由于Sr掺杂修饰了表面性质，如Fe(II)/Fe（III）氧化还原对的快速转变，大量的氧空位和表面羟基，此外，PMS和Fe位点之间的强相互作用以及lfos -40催化的PMS活化的电子转移也促进了OI的降解。这也促进了大量超氧自由基（o2自由基dot -）和单重态氧（1O2）的生成，后者被测试为主要的活性氧（ROSs）。铁和氧的协同作用保证了ROSs的连续生成和优异的催化性能。最后，无论是5.0-9.0的宽pH范围，还是共存的阴离子（Cl−和HCO3−），对OI去除的抑制作用都可以忽略不计，这表明LSFO-40/PMS系统在实际废水处理中具有很大的应用潜力。
A-site doping of perovskite has been considered to be an effective method to simultaneously boost catalytic performance and limit metal release in heterogeneous catalysis. Herein, various Sr-doped LaFeO3perovskites (La1-xSrxFeO3-δ) were synthesized and evaluated as a heterogeneous catalyst to activate peroxymonosulfate (PMS) for the degradation of Orange I (OI) in water. Specifically, La0.6Sr0.4FeO3-δ(LSFO-40) exhibited a remarkable improvement in catalytic activity with akconstant of 0.0411 min−1, which was approximately 3 times higher than that of LaFeO3(0.0142 min−1). The superior stability was obtained with less metal leaching after Sr doping. Such enhancement was mainly attributed to the modified surface properties created by Sr doping, such as a rapid transformation of Fe(II)/Fe(III) redox pair, a large number of oxygen vacancies and surface hydroxyl groups, additionally, the strong interaction between PMS and Fe sites and facilitated electron transfer for PMS activation catalyzed by LSFO-40 also stimulated OI degradation. These also promoted the generation of a considerable amount of superoxide radical (O2radical dot−) and singlet oxygen (1O2), which was tested as the main reactive oxygen species (ROSs). The synergistic effect of iron and oxygen species ensured a continuous ROSs generation and excellent catalytic performance. Finally, neither a wide pH range of 5.0–9.0 or co-existing anions (Cl−and HCO3−) showed a negligible inhibitory effect on OI removal, implying a great potential application of the LSFO-40/PMS system in practical wastewater treatment.