A carbon felt cathode modified by acidic oxidised carbon nanotubes for the high H₂O₂ generation and its application in electro-Fenton

ABSTRACT

Herein, a carbon felt (CF) cathode modified by the acidic oxidised carbon nanotubes (OCNTs) exhibited a high yield of the H₂O₂ generation in electro-Fenton. Rotating disk electrode (RDE) measurements showed that the selective generation of H₂O₂ occurred on the CF cathode coated by OCNTs (OCNTs/CF), which was attributed to the high amount of oxygen-containing functional groups in OCNTs. Moreover, the pollutant degradation efficiency could almost reach 100% within 60 min in electro-Fenton with OCNTs/CF as the cathode. Furthermore, the pollutant removal efficiency was kept constant after five consecutive cycles, indicating the high stability of OCNTs/CF cathode. Besides, the hydrophilicity of OCNTs/CF cathode was significantly enhanced owing to the abundant oxygen-contained functional groups on the surface of the OCNTs/CF cathode, which facilitated the mass transfer between the OCNTs/CF cathode and the reactants in the bulk solution. To reveal the possible mechanism in electro-Fenton equipped with the OCNTs/CF cathode, quenching experiments and electron paramagnetic resonance (EPR) investigations were further conducted. This work provided valuable insights into the fabrication of the non-metallic cathode with a high ability towards H₂O₂ generation in electro-Fenton for efficient pollutant removal.

GRAPHICAL ABSTRACT

KEYWORDS:

• Electro-Fenton
• Advanced oxidation process
• Cathode
• Hydrogen peroxide generation
• Oxidised carbon nanotubes

Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (42277194), the Special Project for Serving Local S&T Development of Education Department of Shaanxi Province (21JC022), and the S&T Project of Yulin city, Shaanxi Province (CXY-2021-140).

Data availability statement

The authors confirm that the data supporting the findings of this study are available on request from the corresponding author

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [grant number 42277194], the Special Project for Serving Local S&T Development of Education Department of Shaanxi Province [grant number 21JC022] and the S&T Project of Yulin city in Shaanxi Province [grant number CXY-2021-140].