Simultaneously Providing Iron Source toward Electro-Fenton Process and Enhancing Hydrogen Peroxide Production via a Fe3O4 Nanoparticles Embedded Graphite Felt Electrode

Tingting Lian; Chao Huang; Feng Liang; Xinyong Li; Jingyu Xi

doi:10.1021/acsami.9b16236

Simultaneously Providing Iron Source toward Electro-Fenton Process and Enhancing Hydrogen Peroxide Production via a Fe₃O₄ Nanoparticles Embedded Graphite Felt Electrode

ACS Appl Mater Interfaces. 2019 Dec 11;11(49):45692-45701. doi: 10.1021/acsami.9b16236. Epub 2019 Dec 3.

Authors

Tingting Lian^{1

2}, Chao Huang^{2

3}, Feng Liang⁴, Xinyong Li¹, Jingyu Xi²

Affiliations

¹ State Key Laboratory of Fine Chemicals, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology , Dalian University of Technology , Dalian 116024 , China.
² Tsinghua Shenzhen International Graduate School , Tsinghua University , Shenzhen 518055 , China.
³ School of Materials Science and Engineering , Tsinghua University , Beijing 100084 , China.
⁴ The State Key Laboratory of Refractories and Metallurgy, School of Chemistry and Chemical Engineering , Wuhan University of Science and Technology , Wuhan 430081 , China.

PMID: 31742993
DOI: 10.1021/acsami.9b16236

Abstract

Electro-reduction of O₂ to generate H₂O₂ is an attractive alternative to the current anthraquinone process and quite necessary for chemical industries and environmental remediation. In general, sufficient porous structure contributes to expose more catalytic active sites and shorten diffusion paths for the heterogeneous catalysis of O₂. In this work, initially the Fe₃O₄ nanoparticles embedded graphite felt (Fe₃O₄@GF) is prepared through a mild hydrothermal following with thermal reduction method. This special combination not only provides iron source for the electro-Fenton reaction but also supplies rich active sites from the Fe₃O₄ embedded structure with abundant cracks, which are beneficial to increase the reaction rate. Compared with raw graphite felt (RGF), fresh Fe₃O₄@GF exhibits superior pollutant degradation kinetics with more than 400% increase and approximately 37.8% improvement to the removal of total organic carbon. A 98% decolorization of rhodamine B (RhB) can be achieved in just 5 min and quickly completes 100% removal of RhB in the next few seconds. As the electro-Fenton reaction progresses, Fe₃O₄ dissolves in the electrolyte, leaving a porous structure on the surface of the GF to form a porous GF (PGF), and the rapid radical reaction activates the GF surface. Both the chemical etching of Fe₃O₄ and the electro-Fenton process can further increase the specific surface area, defects, and actives sites of the electrode. As expected, the active PGF exhibits favorable performance of H₂O₂ production in electrolytes of different pHs: 1 (320.0 ± 36.5 mg L^-1), 3 (301.9 ± 13.2 mg L^-1), and 7 (320.4 ± 21.2 mg L^-1). The degradation performance of PGF does not significantly decay even after 20 cycles of repeated use, indicating the good structural stability and long-term durability. The superiority of the in situ Fe source and fast reaction kinetics for electro-Fenton of Fe₃O₄@GF is confirmed, and this holey engineered strategy also provides the possibility to achieve swift water purification and open up a new way for developing efficient carbon-based electrodes.

Keywords: Fe3O4; degradation kinetics; electro-Fenton reaction; hydrogen peroxide production; porous graphite felt.