1. Heterogeneous Fe2CoTi3O10-MXene composite catalysts: Synergistic effect of the ternary transition metals in the degradation of 2,4-dichlorophenoxyacetic acid based on peroxymonosulfate activation.
- Author
-
Ding, Mingmei, Chen, Wei, Xu, Hang, Shen, Zhen, Lin, Tao, Hu, Kai, Kong, Qing, Yang, Guang, and Xie, Zongli
- Subjects
- *
ELECTRON paramagnetic resonance spectroscopy , *HETEROGENEOUS catalysts , *TRANSITION metals , *CATALYSTS , *HYDROXYL group , *POLLUTANTS , *HUMIC acid - Abstract
• The novel Fe 2 CoTi 3 O 10 -MXene composite was successfully synthesized for PMS activation. • Fe 2 CoTi 3 O 10 -MXene composite exhibited excellent catalytic performance for the 2,4-D removal. • A ternary synergistic degradation was investigated based on Fe, Co and Ti species. • The possible activation mechanism and degradation pathway of 2,4-D were proposed. In this study, a novel Fe 2 CoTi 3 O 10 -MXene (FCT-M) composite was synthesized and employed as a heterogeneous catalyst for the oxidative degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) based on peroxymonosulfate (PMS) activation. The effects of catalyst dosage, PMS dosage, pH of the initial solution, 2,4-D concentration, and the co-existing inorganic ions (HCO 3 − and Cl−) and humic acid (HA) were systematically evaluated. The catalyst with the Fe 2 CoTi 3 O 10 loading (FCT-M-2) of 6.72% demonstrated superior catalytic performance. The results showed that around 98% of 2,4-D degraded in 15 min on using 0.2 g/L FCT-M-2 composite, 0.2 g/L PMS, and 20 mg/L 2,4-D with an initial pH of 7. The co-existence of sulfate radicals (SO 4 −) and hydroxyl radicals (OH) was confirmed based upon electron paramagnetic resonance spectroscopy and radical scavenger tests, while SO 4 − was identified as the main reactive species in the FCT-M/PMS catalytic system. The superior performance of FCT-M based on PMS activation was achieved due to remarkable synergistic effect of the active sites of three transition metals (Fe, Co, and Ti) on the catalyst surface. According to the identified intermediates, a possible 2,4-D degradation pathway is proposed. Overall, this study widens the scope of employing heterogeneous catalysts towards PMS activation and sheds light on the degradation of organic pollutants in aqueous solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF