Degreasing cotton used as pore-creating agent to prepare hydrophobic and porous carbon cathode for the electro-Fenton system: enhanced H2O2 generation and RhB degradation

• Published in: Environmental science and pollution research international 2021-07, Vol.28 (25), p.33570-33582
• Main Authors: Su, Hongzhao, Chu, Yanyang, Miao, Baoyu
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Carbon; Cathodes; Cleaning process; Cotton; Current efficiency; Decoloring; Degreasing; Earth and Environmental Science; Ecotoxicology; Electrochemistry; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fibers; Heat treatment; Heat treatments; Hydrogen peroxide; Hydrophobicity; Mass transfer; Mineralization; Oxidation; Performance degradation; Pollutants; Polytetrafluoroethylene; Research Article; Rhodamine; Sintering (powder metallurgy); Waste Water Technology; Wastewater treatment; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-021-12965-z

A porous carbon cathode was prepared using graphite, polytetrafluoroethylene (PTFE), and degreasing cotton (DC) through sintering treatment. The carbonization of DC by heat treatment played an ideal role in pore-creating, which weakened the mass transfer resistance of O 2 , and as a result, the adoption of degreasing cotton significantly improved the performance of H 2 O 2 electro-generation. The optimized cathode was able to generate 567 mg L −1 H 2 O 2 with a current efficiency (CE) of 86.7% by the electrochemical reaction of 60 min in a divided reactor. Furthermore, the degradation of rhodamine B (RhB) was carried out by an electro-Fenton system using the optimal cathode selected. The developed electro-Fenton system exhibited an excellent RhB degradation performance. The RhB solution of 50 mg L −1 was decolorized completely by the treatment of 10 min. Moreover, the degradation of 50~90 mg L −1 RhB solution presented over 90% TOC removal by the treatment of 120 min, indicating the ideal mineralization of organic pollutants. In addition, it was found that •OH was the major oxidizing specie responsible for the organics degradation. Finally, the possible pathway of RhB degradation in the electro-Fenton system was proposed by GC-MS analysis. The adoption of natural fibers for pore-creating provides an innovative and low-cost method to prepare porous cathode, which may promote the application of electro-Fenton oxidation in wastewater treatment. Graphical abstract