Superoxide radicals dominated visible light driven peroxymonosulfate activation using molybdenum selenide (MoSe2) for boosting catalytic degradation of pharmaceuticals and personal care products
In recent years, molybdenum disulfides (MoS 2 ) have been widely recognized as a promising catalyst or cocatalyst in Advanced Oxidation Processes (AOPs); however, the discharge of hydrogen sulfide (H 2 S) after catalytic process is still a key issue that needs to be addressed. Hence, in this study, a superoxide radical (O 2 − ) dominated visible-light-driven peroxymonosulfate activation process has been established by adopting molybdenum selenide (MoSe 2 ) to replace MoS 2 in order to dramatically enhance the catalytic degradation efficiency of three types of pharmaceuticals and personal care products (PPCPs) (e.g., ibuprofen, benzophenone-3 and carbamazepine). This enhancement is due to its exposed surface metallic Mo 4+ ions, accompanied with the oxidization to Mo 5+ and Mo 6+ for further participating in the decomposing of PMS, as well as the photo-generated electrons playing a prominent role in reducing the Mo 5+ and Mo 6+ back to Mo 4+ . Scavenger tests and electron paramagnetic resonance (EPR) identify the O 2 − as the primary reactive oxygen species (ROS) in the MoSe 2 /PMS system, and singlet oxygen ( 1 O 2 ) is mainly derived from the transformation of O 2 − . Density Functional Theory (DFT) is used to explain the elongation of O O bond in the PMS molecule that would facilitate the generation of sulfate radicals and hydroxyl radicals in both of MoSe 2 catalyzed PMS system and cocatalyzed Fe(II) or Fe(III)/PMS systems. Ultimately, the MoSe 2 /PMS system is also applicable for the treatment of actual sewage. This work highlights the important role of photo-generated electrons and molybdenum ions in PMS reduction and oxidation , and establishes theoretical support for further relevant studies.
危险品化学品经营许可证（带存储）