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

Yangyang Wang; Jianfeng Xu; Xiaoshu Wang; Tongtong Li; Gen Zhang; Zheng Yan; Jiancong Liu; Lei Wang

doi:10.3389/fchem.2022.967589

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

Front Chem. 2022 Jul 19:10:967589. doi: 10.3389/fchem.2022.967589. eCollection 2022.

Authors

Yangyang Wang^{1

2}, Jianfeng Xu³, Xiaoshu Wang¹, Tongtong Li⁴, Gen Zhang⁵, Zheng Yan⁶, Jiancong Liu¹, Lei Wang¹

Affiliations

¹ School of Materials and Environmental Engineering, Institute of Urban Ecology and Environment Technology, Shenzhen Polytechnic, Shenzhen, China.
² Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, Fujian Agriculture and Forestry University, Fuzhou, China.
³ Beijing GeoEnviron Engineering & Technology, Inc., Beijing, China.
⁴ Technical Centre for Soil, Agriculture and Rural Ecology and Environment, Ministry of Ecology and Environment, Beijing, China.
⁵ School of Ecology and Environment, Anhui Normal University, Wuhu, China.
⁶ Chinese Society for Environmental Sciences, Beijing, China.

Abstract

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 500^oC. 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.

Keywords: 2,4-dichlorophenol; DFT calculation; Fe3O4-encapsulated biochar; biomimetic synthesis; peroxydisulfate.