Degradation of methylene blue by a heterogeneous Fenton reaction catalyzed by FeCo2O4-N-C nanocomposites derived by ZIFs

• Published in: Powder technology 2021-05, Vol.383, p.212-219
• Main Authors: Zhang, Ting, Ma, Qingqing, Zhou, Mengqi, Li, Changyu, Sun, Jianchao, Shi, Weijie, Ai, Shiyun
• Format: Article
• Language: English
• Subjects: Bimetals; Catalysts; Catalytic activity; Cobalt; Degradation; Durability; Environmental degradation; FeCo2O4-N-C-400; Fenton reaction; Free radicals; Iron; Methylene blue; Nanocomposites; Nanomaterials; Nanotechnology; Nitrogen; Peroxymonosulfate; Pollutants; Reactive oxygen species; Recyclability
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2021.01.051

Rationally designing efficient nanomaterials for heterogeneous activation of peroxymonosulfate (PMS) is necessary for environmental remediation. Nitrogen-containing carbon/FeCo2O4 composites (FeCo2O4-N-C) were prepared by annealing the iron and cobalt in the ZIF-67 (Fe-Co-ZIF) precursor at different reaction temperatures. In the presence of PMS, 400 °C calcined nitrogen-containing carbon/FeCo2O4 composites (FeCo2O4-N-C-400) was used as catalyst for heterogeneous Fenton degradation of methylene blue (MB) and nearly 100% MB was removed within 10 min without pH adjustment. FeCo2O4-N-C-400 had excellent catalytic activity profiting from the uniform distribution of bimetals and nitrogen doping, which ensured the exposure of sites with high catalytic activity. Free radical quenching experiments showed that a large number of reactive oxygen species (SO4.- and .OH) were the cause of pollutant degradation. At the same time, the possible degradation mechanism of MB in FeCo2O4-N-C-400/PMS system was proposed. In addition, FeCo2O4-N-C-400 can still degrade 60% of MB after four cycles, which indicated that the catalyst had long-term catalytic durability and recyclability. [Display omitted] •The prepared FeCo2O4-N-C had the characteristics of nitrogen and bimetal doping.•FeCo2O4-N-C-400 showed a polyhedral morphology with the rougher and looser surface.•FeCo2O4-N-C can activate PMS to degrade methylene blue without pH adjustment.•Sulfate radicals and hydroxyl participating in Fenton-like process were evidenced.•FeCo2O4-N-C had long-term catalytic durability and recyclability.