Fe sub(3)O sub(4)SiO sub(2) nanoparticles as a high-performance Fenton-like catalyst in a neutral environment

Advanced oxidation processes (AOP) have been widely applied in water treatment. However, traditional Fenton reactions based on a Fe super(2+)-H sub(2)O sub(2) system requires an acidic environment and generates a large amount of Fe super(3+) ions. Herein, we reported that magnetic Fe sub(3)O sub(4) core-SiO sub(2) shell nanoparticles (Fe sub(3)O sub(4)SiO sub( 2) NPs) could be used as a Fenton-like catalyst for the decomposition of H sub(2)O sub(2), resulting in the decoloration of methylene blue (MB). Fe sub(3)O sub(4)SiO sub(2 ) NPs had much higher activity than bare Fe sub(3)O sub(4) cores, suggesting the coating of SiO sub(2) enhanced the catalytic activity. Most importantly, the best performance of Fe sub(3)O sub(4)SiO sub(2 ) NPs was observed at neutral pH values. A higher temperature facilitated the diffusion of MB in solution, and thus, promoted the decoloration efficiency. The radical reaction nature was reflected by the electron spin resonance spectrum and the significant inhibition of the decoloration in the presence of the radical scavenger tertiary butanol. Fe sub(3)O sub(4)SiO sub(2 ) NPs could be magnetically separated and partially regenerated after the decoloration. The implication for the applications of Fe sub(3)O sub(4)SiO sub(2 ) NPs in water treatment is discussed.