Fast removal of bisphenol A by coconut shell biochar incorporated α-MnO2 composites via peroxymonosulfate activation

In this study, a series of coconut shell biochars (CSB) with different pyrolysis temperature were prepared and incorporated with α-MnO 2 for bisphenol A (BPA) degradation in water through activating peroxymonosulfate (PMS). The results showed that with the assistance of CSB, α-MnO 2 /CSB exhibited superior catalytic activity over pristine α-MnO 2 , in which CSB played multiple roles in the composite. Basically, CSB could effectively improve the dispersion and expose more active sites of α-MnO 2 . Besides, CSB could build solid interactions with α-MnO 2 and boost the electron transferring rate between catalyst, PMS and BPA. Moreover, α-MnO 2 and CSB were both enrolled in the generation of radical and non-radical species for BPA degradation. Having multiple active species, the α-MnO 2 /CSB composite could maintain high catalytic performance under a wide pH range with good reusability and adaptability. The existence of both radical and non-radical pathways was further verified through identifying the BPA degradation intermediates. This study provides a new insight for the design of novel composite catalyst for water decontamination using biochar as a multifunctional participant.