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. [Display omitted] •Hollow tubular MoS2 (htMoS2) was doped with Ru for peroxymonosulfate (PMS) activation and carbamazepine (CBZ) degradation.•Ru afforded the main responsibility for PMS activation, and htMoS2 accelerated the Ru redox cycles.•The 5.7Ru-htMoS2/PMS system performed preeminently on CBZ removal and good resistance to environmental interferences.•The dominant production of non-radical 1O2 made contribution to these advantageous performances.