Yang Qina, Niu Xuyao, Zhu Yongjian, Cui Yu, Chao Yang, Liang Ping, Zhang Chi, Wang Shaobin
School of Applied Physics and Materials, Wuyi University, Jiangmen, China.
School of Applied Physics and Materials, Wuyi University, Jiangmen, China.
J Hazard Mater. 2022 Jun 15;432:128686. doi: 10.1016/j.jhazmat.2022.128686. Epub 2022 Mar 12.
Perovskite oxides are promising catalysts in peroxymonosulfate (PMS) activation for wastewater treatment, attributed to their flexible structures. In this study, halogen anion (F or Cl) was doped in LaSrCoFeO (LSCF) for PMS activation, showing that appropriate anion doping enhances the catalytic performances. LaSrCoFeOCl (LSCFCl) exhibits a superior catalytic activity to pristine LSCF and LaSrCoFeOF (LSCFF), attributed to the strong surface acidity, sufficient oxygen vacancies, and improved B-site metal-oxygen bonding. The rich acidic sites favor PMS adsorption on the catalyst surface. The sufficient hydrated electrons (e) in the oxygen vacancies participated in the generation of free radicals (SO and O) and singlet oxygen (O). The enlarged B-site metal-oxygen covalency could boost the electron transfer between PMS and Co/Fe, and thus accelerate the redox reaction. SO and O are the dominating species for the degradation. This study deepens the catalytic mechanism and uncovers the active sites of perovskite catalysts for PMS activation, providing an inspiring modification strategy to improve the catalytic performances.
钙钛矿氧化物因其结构灵活，在过一硫酸盐（PMS）活化用于废水处理方面是很有前景的催化剂。在本研究中，卤阴离子（F或Cl）被掺杂到LaSrCoFeO（LSCF）中用于PMS活化，结果表明适当的阴离子掺杂可提高催化性能。LaSrCoFeOCl（LSCFCl）对原始LSCF和LaSrCoFeOF（LSCFF）表现出优异的催化活性，这归因于其强表面酸性、充足的氧空位以及改善的B位金属 - 氧键合。丰富的酸性位点有利于PMS吸附在催化剂表面。氧空位中充足的水合电子（e）参与了自由基（SO和O）和单线态氧（O）的生成。扩大的B位金属 - 氧共价性可促进PMS与Co/Fe之间的电子转移，从而加速氧化还原反应。SO和O是降解的主要物种。本研究深化了催化机理，揭示了钙钛矿催化剂用于PMS活化的活性位点，提供了一种鼓舞人心的改性策略来提高催化性能。
