MoO2-enhanced Fe-loaded biochar promotes Fe2+/Fe3+ cycling for activation of peroxydisulfate to degrade organic pollutants
Binbin Wu, Zheng Wang, Zheng Wang, Yannan Jia, Nannan Xu, Lisha Liao, Chenyue Zhang, Zhiwei Wang, Zhiwei Wang, Yuanxiang Shan, Wanting Feng, Hongqin Xue
Abstract
Biochar loaded with bimetallic Fe/Mo (Fe/Mo-BC) was prepared as a cost-effective catalyst for the degradation of organic matter by activated peroxydisulfate, in which MoO2 was used as a co-catalyst to enhance Fe2+/Fe3+ cycling. The tetracycline-degradation efficiency of the system reached 74.49 % within 10 min, and it showed high removal rates over a wide pH range (3–9). Quenching experiments and electron paramagnetic resonance analyses showed that 1O2, •OH, O2•-, and SO4•− produced by the Fe/Mo-BC/PDS system are involved in tetracycline degradation, with 1O2 and •OH being the dominant active substances. X-ray photoelectron spectroscopy analysis revealed that Mo(IV) reduces Fe3+ to Fe2+ and oxidizes itself to Mo(VI). In addition, the Fe/Mo-BC remained stable and could be recycled three times, indicating the feasibility of this system for practical applications. The possible pathways of TC degradation by this system were investigated by LC-MS and DFT calculations. Thus, the present study provides a feasible strategy for the use of biochar-loaded bimetallic materials and PDS for the degradation of organic matter.