Hydroxylamine-facilitated degradation of rhodamine B (RhB) and p-nitrophenol (PNP) as catalyzed by Fe@Fe2O3 core-shell nanowires

Fe@Fe 2 O 3 core-shell nanowire is a promising heterogeneous Fenton iron catalyst to degrade organic pollutants. So far, the roles of hydroxylamine (HA) in Fe@Fe 2 O 3 /HA system for pollutant degradation still remain unknown. In this study, the HA-facilitated degradation of rhodamine B (RhB) and p-nitrophenol (PNP) by Fe@Fe 2 O 3 was reported and the underlying mechanisms were explored. Results show that addition of HA significantly enhanced degradation of organic pollutants and a higher HA dosage caused a faster degradation rate . The degradation process was completely inhibited by scavengers, indicating the hydroxyl radical (HO ) from bulk solution dominated the reactions. HA in the Fe@Fe 2 O 3 /H 2 O 2 /HA system was highly efficient to promote the generation of HO by accelerating both the Fe 3+ /Fe 2+ cycle and the H 2 O 2 decomposition. Meanwhile, HA itself was rapidly decomposed along with the pollutants degradation. About 50.5% of RhB and 46.4% of PNP were mineralized in the presence of HA. The effective pH value for degradation was expanded from 4.0 to 5.0. The EE/O calculations demonstrate that a higher energy input for PNP was required than that for RhB. This study will shed lights on the reactivity of the Fe@Fe 2 O 3 /HA system and provide an alternative pathway for removal of organic contaminants.