Non-Radical Activation of Low Additive Periodate by Carbon-doped Boron Nitride for Acetaminophen Degradation: Significance of High-potential Metastable Intermediates

Metal-free environmental-friendly and cost-effective catalysts for periodate (PI) activation are crucial to popularize their application for micropollutant removal in water. Herein, we report that carbon-doped boron nitride (C-BN) can efficiently activate PI to degrade acetaminophen under very low oxidant doses (40 μM) and over a relatively wide pH range (3-9). As expected, the significant reduction in periodate addition is likely to be due to the higher chemical utilization efficiency achieved by a non-radical oxidation pathway. This involved two main mechanisms, the electron transfer process mediated by the high-potential metastable C-BN-900-PI* complex and singlet oxygen. In this case, the C=O groups and defects on the C-BN surface were identified as key active sites for PI activation. Notably, the prepared C-BN-900 had good cycling performance and the degradation efficiency is recovered after simple annealing. The existence of HCO3− and HA significantly inhibited the reaction, whereas Cl−, SO42−, and NO3− had little effect on the degradation of ACE. Overall, this study provides a new alternative method to regulate the non-radical pathway of boron nitride/periodate system.