Cobalt oxyhydroxide (CoOOH) has been turned out to be a high-efficiency catalyst for peroxymonosulfate (PMS) activation. In this study, CoOOH was loaded on bismuth oxide (Bi₂O₃) using a facile chemical precipitation process to improve its catalytic activity and stability. The result showed that the catalytic performance on the 2,4-dichlorophenol (2,4-DCP) degradation was significantly enhanced with only 11 wt% Bi₂O₃ loading. The degradation rate in the CoOOH@Bi₂O₃/PMS system (0.2011 min⁻¹) was nearly 6.0 times higher than that in the CoOOH/PMS system (0.0337 min⁻¹). Furthermore, CoOOH@Bi₂O₃ displayed better stability with less Co ions leaching (16.4% lower than CoOOH) in the PMS system. These phenomena were attributed to the Bi₂O₃ loading which significantly increased the conductivity and specific surface area of the CoOOH@Bi₂O₃ composite. Faster electron transfer facilitated the redox reaction of Co (III) / Co (II) and thus was more favorable for reactive oxygen species (ROS) generation. Meanwhile, larger specific surface area furnished more active sites for PMS activation. More importantly, there were both non-radical (¹O₂) and radicals (SO₄⁻•, O₂⁻•, and OH•) in the CoOOH@Bi₂O₃/PMS system and ¹O₂ was the dominant one. In general, this study provided a simple and practical strategy to enhance the catalytic activity and stability of cobalt oxyhydroxide in the PMS system.

羟基氧化钴（CoOOH）已被证明是用于过氧一硫酸盐（PMS）活化的高效催化剂。在这项研究中，使用简便的化学沉淀工艺将CoOOH负载在氧化铋（Bi ₂ O ₃）上，以提高其催化活性和稳定性。结果表明，仅以11wt％的Bi ₂ O ₃负载，对2，4-二氯苯酚（2，4-DCP）降解的催化性能显着增强。CoOOH @ Bi ₂ O ₃ / PMS系统（0.2011 min ^-1）的降解速率比CoOOH / PMS系统（0.0337 min ^-1）的降解速率高近6.0倍。此外，CoOOH @ Bi ₂ O ₃在PMS系统中显示出更好的稳定性，且Co离子的浸出更少（比CoOOH低16.4％）。这些现象归因于Bi ₂ O ₃负载，该负载显着增加了CoOOH @ Bi ₂ O ₃复合材料的电导率和比表面积。更快的电子转移促进了Co（III）/ Co（II）的氧化还原反应，因此更有利于活性氧（ROS）的产生。同时，较大的比表面积为PMS活化提供了更多的活性部位。更重要的是，CoOOH @ Bi ₂中同时存在非自由基（¹ O ₂）和自由基（SO ₄ ⁻ •，O ₂ ⁻ •和OH•）O ₃ / PMS系统和¹ O ₂是主要的系统。总的来说，这项研究提供了一种简单实用的策略来增强PMS系统中羟基氧化钴的催化活性和稳定性。