Carbon-Encapsulated Fe3c Nanoparticles for Catalytic Ozonation of Silicon-Containing Wastewater: Dual Improvement of Silicon Resistance and Catalytic Effect

The improvement of catalysts’ stability under harsh reaction conditions is vital for expanding their applicability. Herein, iron carbide (Fe3C) nanoparticles were encapsulated in graphitic carbon in situ and a carbon ball served as the carrier. The synthesized Fe3C@C/C was then utilized to treat an m-cresol wastewater containing Si via catalytic ozonation. The catalyst exhibits improved resistance to Si because of the dual protection from the carbon-encapsulated structure and carbon carrier. Density functional theory calculations show that the encapsulation of Fe3C using carbon significantly increases the resistance to adsorption of Si on its active sites. In addition, the activation of O3 is unimpeded on the Fe3C adsorption sites by the protection from C, thus the generation of reactive oxygen species (ROS) by ozone is largely promoted. The mechanism associated with the resistance of the Fe3C@C/C catalyst to Si and its elevated activity are also elucidated.