Boosting the activation of peroxydisulfate and the degradation of ofloxacin over polyaniline-derived N/B co-doped carbon through electron transfer dominated oxidation processes

Abstract

Persulfate advanced oxidation processes (PS-AOPs) based on non-radical pathways present great promise for complex aquatic environmental decontamination. Developing high-performance carbon-based materials to facilitate non-radical pathways is an effective strategy to promote their practical applications. In this study, a novel N/B co-doped carbon (CNB-1000) was simply synthesized via carbonization of boronic acid-doped polyaniline. The CNB-1000/PDS system could remove nearly 100 % OFX (0.01 g/L) within 45 min with a rate constant (k) of 0.12 min−1, reaching 3.8 times that of the N-doped material (CN-1000). This system exhibited interference resistance, favorable reusability and suitability for the degradation of the electron-rich contaminants. The mechanism study verified that electron transfer is the primary pathway in the system and singlet oxygen plays an auxiliary role. In addition, the density functional theory (DFT) calculations elucidated that the BN3 structure is the main active site that forms an inside-out electron delocalization as new electron transfer channel that facilitates electron transfer pathway. This study presents a simple method for the preparation of N/B co-doped carbon-based catalysts and deepens their activation persulfate mechanism for the degradation of ofloxacin, which provides theoretical and technical support for the application of carbon-activated persulfate systems based on the non-radical pathway.