Accelerated Fe3+/Fe2+ cycle in Mo2C-based Fe catalyst to promote peroxymonosulfate activation

• Published in: Chemosphere (Oxford) 2024-11, Vol.367, p.143380, Article 143380
• Main Authors: Ying, Yunzhan, Liang, Shikun, Zhang, Fayang, Xu, Xiangwei, Qian, Chenbo, Jiang, Long, Zhou, Jing, Wan, Yulong, Wang, Lie, Yao, Yuyuan
• Format: Article
• Language: English
• Subjects: catalysts; electron paramagnetic resonance spectroscopy; Heterogeneous iron catalysts; Molybdenum carbide; Organic pollutants; Peroxymonosulfate; remediation; singlet oxygen; species; sulfates; wastewater; Water treatment
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2024.143380

The harmful impact of organic pollutants on aquatic ecosystems underscores the pressing need for effective remediation. While activating peroxymonosulfate (PMS) with Fe catalyst offers a promising approach for eliminating these pollutants, its widespread use is hindered by the sluggish regeneration of Fe2+ from Fe3+. Here, this study demonstrates for the first time that combining an Fe catalyst with Mo2C (Fe-Mo2C) enhances the Fe³⁺/Fe2⁺ cycle, thereby improving PMS activation. The Fe-Mo2C/PMS system achieved near-complete degradation of carbamazepine (CBZ) within only 8 min, with an impressive observed rate constant (kobs) of up to 0.624 min−1, about 15 times greater than that of Fe-C catalyst. It also exhibits the capability to degrade a broad range of common antibiotics, phenols, and dye-like organic compounds. Through electron paramagnetic resonance (EPR) analysis and quenching experiments, it was verified that hydroxyl radicals (·OH), sulfate radicals (SO4·-), singlet oxygen (1O2), and superoxide radicals (·O2−) species during the reaction, with the former three serving as the primary active species. These findings offer a hopeful avenue for the systematic development and enhancement of catalysts specifically designed to efficiently remediate organic pollutants in wastewater. [Display omitted] •A novel Fe-Mo2C catalyst was synthesized using a coprecipitation and calcination method.•The introduction of Mo2C accelerated the Fe3+/Fe2+ cycle for peroxymonosulfate activation.•The catalytic system achieved a notable rate constant of 0.624 min−1 for carbamazepine removal.•SO4·-, ·OH, 1O2 and ·O2− were identified as the primary active species.