Degradation of bisphenol A in an oxidation system constructed from Mo2C MXene and peroxymonosulfate

The etched Mo 2 C MXene with a layered structure was characterized as an environmentally friendly catalyst in the bisphenol A (BPA) removal by advanced oxidation. 99.75% of BPA was degraded in the oxidation system constructed using Mo 2 C MXene and peroxymonosulfate (PMS). The Mo 2 C MXene was recyclable, with a high removal percentage (89.29%) of BPA after even four cycles. The catalysis of Mo 2 C MXene on PMS was due to the Mo-deficit vacancy defects. The electron paramagnetic resonance technique and density functional theory (DFT)-based density of states calculations verified defect signals. In addition, the defective Mo 2 C MXene and PMS have strong binding and electron transfer capabilities. The reactive oxygen species (ROS, including O 2 •− , 1 O 2 , SO 4 •− , and • OH) produced by Mo 2 C MXene activates PMS, leading to BPA degradation. The condensed Fukui function predicted the active sites of the BPA molecule and found that the O1, O2, C3, C4, C6, C12, C15, and C16 sites have higher electrophilic reactivity. The C, C–C bonds, or C4/C16 sites in the isopropyl group connecting the two phenolic rings were attacked first, then further transformed BPA into non-toxic or low toxic small molecule degradation products through a series of reactions such as bond-breaking, addition, hydroxylation, and ring-opening. Moreover, the Mo 2 C MXene/PMS system has strong applicability in actual water bodies. The study provides valuable insights into PMS activation by two-dimensional MXenes to remove toxic organic pollutants in an aqueous matrix.