College of Resource and Environment, Qingdao Agricultural University, Qingdao 266109, China.
College of Resource and Environment, Qingdao Agricultural University, Qingdao 266109, China; Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
J Colloid Interface Sci. 2022 Nov 15;626:629-638. doi: 10.1016/j.jcis.2022.06.144. Epub 2022 Jun 30.
Catalytic activity is the main obstacle limiting the application of peroxymonosulfate (PMS) activation on transition metal oxide catalysts in organic pollutant removal. Herein, ultrasonic treatment was applied to α-MnO to fabricate a new u-α-MnO catalyst for PMS activation. Dimethyl phthalate (DMP, 10 mg/L) was almost completely degraded within 90 min, and the pseudofirst-order rate constant for DMP degradation in the u-α-MnO/PMS system was ∼7 times that in the initial α-MnO/PMS system. The ultrasonic treatment altered the crystalline and pore structures of α-MnO and produced defects on the u-α-MnO catalyst. According to the XPS, TG, and EPR results, higher contents of trivalent Mn and oxygen vacancies (OVs) were produced on the catalyst surfaces. The OVs induced the decomposition of PMS to produce O, which was identified as the main reactive oxygen species (ROS) responsible for DMP degradation. The u-α-MnO catalyst presented great reusability, especially by ultrasonic regeneration of OVs toward the used catalyst. This study provides new insights into regulating OVs generation and strengthening catalyst activity in the PMS activation process for its application in water purification.
催化活性是限制过一硫酸盐（PMS）在过渡金属氧化物催化剂上用于有机污染物去除的主要障碍。在此，采用超声处理来制备新型 u-α-MnO 催化剂以活化 PMS。二甲苯（DMP，10mg/L）在 90min 内几乎完全降解，u-α-MnO/PMS 体系中 DMP 的假一级降解速率常数是初始α-MnO/PMS 体系的约 7 倍。超声处理改变了α-MnO 的晶型和孔结构，并在 u-α-MnO 催化剂上产生了缺陷。根据 XPS、TG 和 EPR 结果，催化剂表面产生了更高含量的三价 Mn 和氧空位（OVs）。OVs 诱导 PMS 分解产生 O，这被鉴定为降解 DMP 的主要活性氧物种（ROS）。u-α-MnO 催化剂具有很好的可重复使用性，特别是通过超声再生 OVs 来实现对使用过的催化剂的再生。本研究为调节 OVs 的生成和增强 PMS 活化过程中的催化剂活性提供了新的见解，有望将其应用于水净化领域。
