(A) C 1s XPS spectra of POP-rGO NSs and EPR spectra of GO, rGO, POP-rGO NSs, and POP. (B) Distributions of electrostatic potential (ESP) for different graphene fragments that O atom located in different positions via DFT calculations: No O atom (represents pure graphene), O atom in the surface oxygen functional groups (represents GO or rGO (with –OH groups)), and O atom in C–O–C bonding bridge that connected the graphene and POP molecule (represents POP-rGO NSs fragment). (C) 2-CP degradation curves in various suspensions with H₂O₂ and actual and stoichiometric H₂O₂ consumptions and the utilization efficiency of H₂O₂ during 2-CP degradation in the POP-rGO NSs suspension. Adapted with permission from ref. [36], Copyright©2017, American Chemical Society.