Fabrication of a double-layer membrane cathode based on modified carbon nanotubes for the sequential electro-Fenton oxidation of p-nitrophenol
| Autor: | Dong Wang, Qian Tang, Gao Yonghui, Binglun Li, Chunwei Yang, Zhou Hao, Wenge Ma, Gao Hang |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Scanning electron microscope Health Toxicology and Mutagenesis Inorganic chemistry Carbon nanotube 010501 environmental sciences 01 natural sciences law.invention Nitrophenols Diffusion layer symbols.namesake X-ray photoelectron spectroscopy law Environmental Chemistry Rotating disk electrode Electrodes 0105 earth and related environmental sciences Nanotubes Carbon Hydrogen Peroxide General Medicine Pollution Cathode symbols Cyclic voltammetry Raman spectroscopy Oxidation-Reduction Water Pollutants Chemical |
| Zdroj: | Environmental Science and Pollution Research. 27:18773-18783 |
| ISSN: | 1614-7499 0944-1344 |
| Popis: | To improve the electrocatalytic efficiency of the cathode and provide a wider pH range in the electro-Fenton process, N-doped multi-walled carbon nanotubes (NCNTs) and ferrous ion complexed with carboxylated carbon nanotubes (CNT-COOFe2+) were used to fabricate the diffusion layer and catalyst layer of a membrane cathode, respectively. The morphology, structure, and composition of CNT-COOFe2+ were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The oxygen reduction performance of NCNT was evaluated using cyclic voltammetry (CV) and the rotating disk electrode technique (RDE). In addition, a potential application of the cathode in sequential electro-Fenton degradation of p-nitrophenol (p-NP) was investigated. The results revealed that iron was successfully doped on the carboxylated carbon nanotubes in ionic complexation form and the content of iron atoms in CNT-COOFe2+ was 2.65%. Furthermore, the defects on the tube walls provided more reactive sites for the electro-Fenton process. A combination of CV and RDE data indicated that NCNT had better electrocatalytic H2O2 generation activity with a more positive onset potential and higher cathodic peak current response than CNT. A p-NP removal rate of 96.04% was achieved within 120 min, and a mineralization efficiency of 80.26% was obtained at 180 min in the sequential electro-Fenton process at a cathodic potential of − 0.7 V vs SCE and neutral pH. The activity of the used cathode was restored simply through electro-reduction at − 1.0 V vs SCE, and a p-NP removal rate of more than 70% was obtained at 60 min after six regeneration cycles. |
| Databáze: | OpenAIRE |
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