Self-powered electro-Fenton degradation system using oxygen-containing functional groups-rich biomass-derived carbon catalyst driven by 3D printed flexible triboelectric nanogenerator

Abstract From the perspective of sustainability, self-powered electro-Fenton (EF) degradation is a promising trend for accelerating the large-scale application in wastewater treatment. In this work, the method of both energy supply source and preparation of high-quality EF catalysts with excellent catalytic activity is herein explored to upgrade and optimize the EF degradation system. A printed flexible wave-like triboelectric nanogenerator (PFW-TENG) is innovatively fabricated by 3D printing technology to drive EF system for methylene blue (MB) degradation catalyzed by oxygen-containing functional groups-rich N-doped porous carbon materials using artemisia argyi and MgO-ZnCl2 as carbon precursor and dual porogens respectively. The maximum instantaneous open-circuit voltage (Voc) and short circuit current (Isc) of the PFW-TENG can reach 610 V and 1.93 mA, and maximum power density can reach 6.1 W m−2 when the connected load is 1 MΩ. Such high output characteristics undoubtedly provide a strong power supply for the EF reaction. The synthesized optimal oxygen-containing functional groups-rich N-doped porous carbon materials have high N content (4.0 at.%) and large surface area (1302 m2 g−1), and the MB decolorization efficiency is surprisingly up to 98.1% within 58 min in the self-powered EF system driven by PFW-TENG. Moreover, it is found that the content of C–O–C and COOH in the carbon material is positively correlated with the decomposition efficiency. This work innovatively realizes the deep integration of cathode EF technology, oxygen-containing functional groups-rich N-doped porous carbon materials preparation technology, and digital 3D printing technology to electrochemical catalytic degrade organic pollutants, which provides innovative ideas for the large-scale application of self-powered EF systems.