An innovative electro-fenton degradation system self-powered by triboelectric nanogenerator using biomass-derived carbon materials as cathode catalyst

Highlights: • A self-powered electro-Fenton degradation system is demonstrated for the first time. • A novel flexible multilayer TENG with the sponge as the buffer layer is designed. • This work provides a guidance for more rational design of biomass-derived carbon electrocatalysts in electro-Fenton system. Based on the advantages of electro-Fenton (EF) and our works on the flexible design of triboelectric nanogenerator (TENG) and biomass carbon materials, a self-powered EF system is demonstrated. It is driven by a robust and flexible multilayered TENG (RFM-TENG) using carbon materials derived from magnolia flowers as the cathode for oxygen reduction. The synthetic mesoporous carbon materials have a large surface area (1226 m² g⁻¹), favoring dissolved oxygen mass transfer and promoting the oxygen reduction process. With the sponge as the buffer layer and pre-charge injection, the short-circuit current, transferred charge and open-circuit voltage of RFM-TENG are 960 μA, 2.8 μC and 1050 V, respectively, and the maximum power density reaches 5.5 W m⁻² at a load resistance of 1 MΩ. Driven by this RFM-TENG, the persistent organic pollutant, basic orange 2, can be degraded to CO₂ by hydroxyl radical (• OH) generated during EF process. Such mechanism is proposed based on the cyclic voltammogram, gas chromatograph-mass spectrometer, UV−vis spectra and the H₂O₂ measurement. With compelling features of the efficient EF method, versatile TENG and biomass-derived carbon materials, this work pioneers the alliance of TENG, carbon-based electrodes and EF to self-power the organic pollutants degradation for sustainable environmental protection.