Efficient activation of peroxodisulfate by novel bionic iron-encapsulated biochar: The key roles of electron transfer pathway and reactive oxygen species evolution

作者：Wang, Yangyang; Wang, Ying; Wang, Xiaoshu; Chang, Ming; Zhang, Gen; Mao, Xuhui; Li, Ye; Wang, Jinsheng; Wang, Lei^*

来源：Journal of Hazardous Materials, 2023, 443: 130204.

DOI：10.1016/j.jhazmat.2022.130204

• Bionic
• Biochar
• CFe15
• 1
• Electron transfer
• Reactive oxygen species

In this study, a novel iron-encapsulated biochar (Fe@BC) was prepared using the biomass cultivated with an iron-containing solution. The iron in Fe@BC showed the phase change from Fe3O4 to alpha-Fe, and to CFe15.1, with the increase of pyrolysis temperature (500-900 degrees C), and a graphene shell formed on the surface of Fe@BC. In addition, the signals assigned to the pi-pi* shake up, pyridinic N, graphitic N, and defects of Fe@BC were found to be stronger as the pyrolysis temperature increased. The F4@B9 sample, which was prepared at 900 degrees C, exhibited an excellent performance (98.01 %) to activate peroxydisulfate (PDS) for the degradation of 2,4-dichlorophenol. Electron paramagnetic resonanceand chemical quenching experiments revealed that reactive oxygen radicals (ROS) including sulfate radical (center dot SO4-), hydroxyl radical (center dot OH), superoxide radical (center dot O2- ), and singlet oxygen (1O2) existed in the F4@B9/PDS system. Furthermore, the micro-electrolysis process facilitated the generation of center dot O2- (12.35 %) and 1O2 (6.49 %) compared with the pure PDS system. Density functional theory revealed that, for the F4@B9-activated PDS process, the graphene shell of F4@B9 served as catalytic active sites as well. According to the correlation analysis, the iron specie of CFe15.1 was more favorable for the generation of ROS than alpha-Fe. Also, n-n* shake up, pyridinic N, graphitic N, and defects participated in the PDS activation. This study provides a new method for the preparation of high-performance catalysts from naturally grown biomass with high iron contents.

• 单位
  清华大学; 武汉理工大学; 中国环境科学研究院; 武汉大学; 桂林理工大学