Iron cobalt and nitrogen co-doped carbonized wood sponge for peroxymonosulfate activation: Performance and internal temperature-dependent mechanism

The directional regulation of oxidation capacity in the carbon-based peroxymonosulfate (PMS) activation system is a promising strategy for wastewater purification. In this work, a novel iron cobalt and nitrogen co-doped carbonized wood sponge (FeCoNCWS) was developed. A superb catalytic performance for sulfamethoxazole (SMX) degradation (~& nbsp;100.0%) was obtained within 30 min in FeCoNCWS800/PMS system at 60 degrees C. Besides, the reactive oxygen species (ROS) contribution was verified at different reaction temperatures. Specifically, the primary roles of sulfate and hydroxyl radicals (SO4 center dot- and (OH)-O-center dot) in SMX removal weakened, while the secondary role of singlet oxygen (O-1(2)) in SMX degradation was enhanced with the rise of reaction temperature in FeCoNCWS800/PMS system. Interestingly, defects, graphitic N and car-bonyl (C@O) groups were vital active sites for PMS activation to produce O-1(2), which was facilitated at higher reaction temperature. Besides, the metal sites were identified as PMS activators for SO(4)(center dot-& nbsp;)and (OH)-O-center dot generation, which was promoted under lower reaction temperature. The findings revealed a novel internal temperature-dependent PMS activation mechanism, which can help to regulate the oxidation capacity of PMS activation system rationally for pollutant degradation. (C)& nbsp;2022 Elsevier Inc. All rights reserved.

Automated summary

This study developed a novel iron cobalt and nitrogen co-doped carbonized wood sponge catalyst for efficient degradation of sulfamethoxazole at low temperature. The research also found that reaction temperature plays a crucial role in the generation and activity of reactive oxygen species, and different species have different roles at different temperatures.