Boosted activity of δ-MnO2 by Kenaf derived carbon fiber for high-efficient oxidative degradation of bisphenol A in water

In this study, kenaf carbon fiber (KCF) was prepared via direct pyrolysis of kenaf fiber. Afterwards, the prepared KCF was incorporated with δ-MnO2 to prepare a series of δ-MnO2/KCF composites. The as-prepared composites were then used to degrade bisphenol A (BPA) in water via oxidative catalysis. Significantly enhanced oxidative capability of the δ-MnO2/KCF was realized, since the KCF could not only prevent δ-MnO2 aggregation, but also facilitate electron transferring between δ-MnO2 and BPA. The impacts of catalyst dosage, initial pollutant concentration, solution pH value, temperature, Mn2+ and natural organic matters on the performance of the δ-MnO2/KCF composites were examined in detail. The results showed that 0.025 mM of BPA could be completely degraded within 10 min by 0.5 g/L of the catalyst at the pH value of 3.80. The subsequent LC-MS analysis results indicated that the δ-MnO2/KCF initiated BPA oxidative degradation and mineralization through capturing one electron from the BPA molecules and forming BPA radicals. Moreover, the as-prepared δ-MnO2/KCF composites also had promising long-time use stability and reusability. This study demonstrates a potentially applicable and sustainable biochar support which could enrich the performance of a catalyst for refractory organic contaminant removals in aqueous environment.