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Rechargeable carbonaceous geosupercapacitor for sustainable superoxide generation and pollutant abatement


Reactive oxygen species enable efficient oxidative removal or detoxification of pollutants in water but traditional approaches for reactive oxygen species generation are chemically demanding, which limits their practical applications. Herein, we demonstrate a sustainable and chemical-free superoxide (O2•−) generation strategy by integrating rechargeable carbonaceous supercapacitors with redox-moiety-based O2 activation, which is distinct from production using traditional electrocatalysis. Highly porous carbonaceous geosupercapacitors were developed by pyrolysing cattle bones consisting of macromolecules interlinked with abundant minerals, followed by acid etching. Porous geosupercapacitors exhibit high capacitances and excellent electron-transfer efficiencies for O2 activation as a result of their abundant carbon defects and redox-active quinone moieties, thereby effectively transferring electrons to O2 to form O2•− radicals. Electrochemical analysis shows that the electron-transfer rate of the carbonaceous geosupercapacitor is orders of magnitude higher than that of traditional biochar, notably promoting electron transfer and O2 activation. This geosupercapacitor possesses excellent electron rechargeability and a stable capacitance, enabling sustainable O2•− production off-line. The utility of this green O2•− producing system is confirmed in different scenarios, such as stable performance in complex matrices, treating diverse redox-active pollutants and development of a portable chargeable device.

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Fig. 1: Preparation and characterization of CGs.
Fig. 2: Superoxide radical identification and its generation mechanism.
Fig. 3: The performance of CGs for oxidizing As(III).
Fig. 4: Electrochemical analysis of CGs.
Fig. 5: Cyclic performance of the rechargeable CG.
Fig. 6: Proof of concept of the rechargeable CG for pollutant abatements.

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All data are presented in the article and its Supplementary Information. Source data are provided with this paper.


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This work was financially supported by the National Natural Science Foundation of China (42321005 (F.L.); 42077301 (L.F.); 42030702 (F.L.); 42207040 (K.L.)), China Postdoctoral Science Foundation (2022M710835 (K.L.)), Guangdong Foundation for talents in scientific and technological innovation (2021TQ060193 (L.F.)), Guangdong Academy of Sciences’ Project (2019GDASYL-0102006 (L.F.)), GDAS Project of Science and Technology Development (2023GDASZH-2023010103 (K.L.); 2022GDASZH-2022010201-04 (L.F.)), Foreign Expert Program (G2023030041L (T.B.)).

Author information

Authors and Affiliations



L.F. conceived and designed this project and wrote the original manuscript. K.L. performed experiments, materials preparation, data analysis and wrote the original manuscript. L.X. contributed to the conduct of the experiments. F.W. contributed to discussions of the results. T.B. and F.L. supervised the entire project and revised the manuscript.

Corresponding authors

Correspondence to Thomas Borch or Fangbai Li.

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The authors declare no competing interests.

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Peer review information

Nature Water thanks Baoshan Xing and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Text 1–4, Figs. 1–16 and Tables 1–4.

Source data

Source Data Fig. 1

Raw data; XRD, BET, Raman, EPR, XPS, CV, EAC/EDC and IR.

Source Data Fig. 2

Radical identification data.

Source Data Fig. 3

The As(III) oxidation by CGs data.

Source Data Fig. 4

Electrochemical analysis of CGs data.

Source Data Fig. 5

Cyclic performance of CGs data.

Source Data Fig. 6

Proof of concept data.

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Fang, L., Liu, K., Xu, L. et al. Rechargeable carbonaceous geosupercapacitor for sustainable superoxide generation and pollutant abatement. Nat Water 2, 485–495 (2024).

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