Biomimetic synthesis technology for preparation of Fe3O4-encapsulated biochar using in highly efficient peroxodisulfate activation

The background value of iron in red soil is superior, primarily absorbed and homogeneously encapsulated in harvested biomass. However, this property on the high-value utilization of bionic iron-encapsulated biomass remains unknown. In this study, special biochar (Fe@BC) was obtained from this kind of biomass by one-step pyrolysis method, which was further used to activate peroxydisulfate (PDS) and degrade 2,4-dichlorophenol (2,4-DCP). The results showed that Fe3O4 was formed and homogeneously embedded in biochar at 500oC. Comparing to catalysts prepared by impregnation pyrolysis (Fe/BC), Fe@BC exhibited excellent degradation performance (90.9%, k = 0.0037 min−1) for 2,4-DCP. According to the free radicals quenching studies, hydroxyl radicals (·OH) and superoxide radicals (·O2−) were the dominant reactive oxygen species (ROS) in Fe@BC/PDS system. Importantly, a PDS adsorption model was established, and the electron transport and PDS activation in the core-shell structure were demonstrated by DFT calculations. Therefore, this study could supply a high-performance catalyst and significant implications for high-value biomass utilization in red soil.