Enhanced paracetamol degradation via strong covalent coupling of Mo[sbnd]O[sbnd]C bonds in C/MoS2 nanocomposites for piezoelectric activation of peroxymonosulfate: Electron bridge and enrichment

Abstract

Paracetamol (PCM) has been frequently detected in natural water bodies, posing potential threats to human health and the natural environment. In this work, we developed a strong covalent coupling system of MoOC within carbon doped MoS2 (C/MoS2) material to piezoelectrically activate peroxymonosulfate (PMS) for PCM degradation. The C/MoS2 was synthesized successfully using one-step hydrothermal method and exhibited 91.8 % of PCM degradation efficiency and 0.04042 min−1 of rate constant (3.29 times of pristine MoS2) within 60 min under ultrasonic vibration. According to characterization and theoretical computational results, the Mo atoms near sulfur vacancies exhibited unsaturation, enabling them to bond with oxygen atoms on carbon substrate, forming a strong covalent coupling structure primarily driven by MoOC bonds. MoOC bonds served as “electron bridges” that efficiently transported electrons from the piezoelectrically excited electron reservoir of MoS2 to the active sites at heterogeneous interfaces, creating electron-rich surface regions and simultaneously inhibiting the recombination of piezoelectric charge carriers, thereby essentially enhancing the intrinsic conductivity of MoS2. Furthermore, as active adsorption sites, MoOC bonds initially strongly adsorbed PMS, activating it into reactive oxygen species (ROS), subsequently absorbing O2 to realize the enrichment of oxides and further promote the PCM decomposition. This work offered new perspectives on the interface modification and development of efficient MoS2-based piezoelectric catalysts for water purification.