Strengthened carbamazepine degradation via producing ¹O₂ with Ru-doped hollow tubular MoS₂ under peroxymonosulfate activation

Molybdenum disulfide (MoS₂) has received increasing concerns in the field of advanced oxidation processes (AOPs) in virtue of its flexible structure and versatility. However, the application of individual MoS₂ is often restricted since its low intrinsic reactivity. In this study, hollow tubular MoS₂ (htMoS₂) with the wall constructed by loosely stacked nanosheets was fabricated. Subsequently, Ru recognized as one of the most effective metals for peroxymonosulfate (PMS) stimulation, was immobilized within htMoS₂ through host-guest Ru-S interactions. The connections ensured the uniform dispersion of Ru centers on substrate in the obtained Ru-htMoS₂, enhancing its catalytic potentials. During PMS activation and carbamazepine (CBZ) degradation, 5.7Ru-htMoS₂ (5.7 referring to Ru loading, wt%) achieved complete removal within merely 30 min under optimal conditions. This remarkable efficiency was attributed to the highly dispersed Ru centers, which played a critical role during PMS activation. Additionally, the htMoS₂ substrate not only played the secondary role to trigger PMS, but also accelerated the redox cycles of Ru³⁺/Ru⁴⁺ to facilitate PMS stimulation. Moreover, the 5.7Ru-htMoS₂/PMS system exhibited high adaptability in a wide pH range along with tolerance to variable anions and cations, and demonstrated a high degradation efficiency in real aqueous matrices. Good sustained stability and further versatility to dyes, phenols and pharmaceuticals were also elicited by the 5.7Ru-htMoS₂/PMS system. These excellent performances were attributed to the predominant roles of non-radical singlet oxygen (¹O₂), which was not easy to actualize in traditional radical processes.