Sustainable self-powered electro-Fenton degradation of organic pollutants in wastewater using carbon catalyst with controllable pore activated by EDTA-2Na

Highlights: • This work pioneers the application of EDTA-2Na in creating controllable pores of carbon materials. • A double layer rotary disc-structured TENG is innovatively fabricated. • This study provides access to other self-powered EF processes with very low power consumption and pollution. -- Abstract: A major challenge of employing electro-Fenton (EF) system for drastically degrading recalcitrant contaminants in industrial wastewater is to develop self-powered system via harvesting universally available and renewable mechanical energy. In this work, a double layer rotary disc-structured triboelectric nanogenerator (DLRD-TENG) based on free-standing triboelectric-layer mode is innovatively fabricated to drive EF system for methylene blue (MB) degradation catalyzed by biomass-based carbon materials using taraxacum mongolicum (TM) and ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) as precursor and porogen, respectively. With the rotating speed rising from 200 to 1000 rpm, the short-circuit current (I_sc) increases from 60 μA to 220 μA, the open-circuit voltage (V_oc) and the transferred charge (Q_tr) almost keep constant, 530 V and 0.4 μC, respectively. When the DLRD-TENG rotates at a speed of 600 rpm, generating a maximum power density of 1.36 W m⁻² (matched load, 1 MΩ), and the EF system with hierarchically porous carbon materials as the cathode could remove up to 96% of MB within 94 min, indicating its high degradation efficiency. These findings comprehensively reveal the feasibility and superiority of TENG as an effective power source in EF system, and pioneer the application of EDTA-2Na in creating controllable pores of carbon materials, which is quite expected and will be enthusiastically gone deep in.