This study addresses the influence of ultrasound irradiation on the activation of peroxymonosulfate (PMS) using reduced graphene oxide (rGO) under metal-free conditions for the catalytic degradation of rhodamine B (RhB), bisphenol A (BPA) and tetracycline (TC). Our results revealed that the combination of PMS/rGO and ultrasonication enhanced significantly the degradation rate, reaching full degradation in relatively short times with total organic carbon (TOC) removal exceeding 85% of the investigated pollutants. In contrast, under these experimental conditions, rGO/ultrasound and PMS/ultrasound achieved less than 20% degradation of the same pollutants. Electron paramagnetic resonance (EPR) studies along with quenching experiments suggested that hydroxyl radicals (^•OH) are the dominant reactive species in the degradation process. Furthermore, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and EPR data revealed the presence of trace manganese (Mn) in rGO. To elucidate the role of Mn on the degradation process, rGO was subjected to hot acid treatment for 48 h to remove trace Mn. While the chemical composition of rGO was not significantly altered by this chemical treatment, the degradation efficiency decreased upon Mn dissolution. The result suggests that trace metal in rGO might account for the efficiency of PMS activation. Finally, plausible degradation pathways were proposed based on LC-MS analysis of the reaction intermediates.

这项研究解决了超声照射对在无金属条件下使用还原型氧化石墨烯（rGO）催化降解若丹明B（RhB），双酚A（BPA）和四环素（TC）的过氧化单硫酸盐（PMS）活化的影响。我们的结果表明，PMS / rGO和超声处理的结合显着提高了降解速率，在相对较短的时间内达到了完全降解，去除的总有机碳（TOC）超过了所调查污染物的85％。相反，在这些实验条件下，rGO /超声波和PMS /超声波对相同污染物的降解不到20％。电子顺磁共振（EPR）研究和淬灭实验表明，羟基自由基（^•OH）是降解过程中的主要反应性物质。此外，电感耦合等离子体原子发射光谱（ICP-AES）和EPR数据显示rGO中存在痕量锰（Mn）。为了阐明Mn在降解过程中的作用，对rGO进行了48 h的热酸处理，以去除痕量Mn。尽管rGO的化学组成并未因该化学处理而显着改变，但降解效率因Mn溶解而降低。结果表明，rGO中的痕量金属可能解释了PMS激活的效率。最后，基于反应中间体的LC-MS分析，提出了可能的降解途径。