Template-assisted self-activation of mesoporous carbon with active nitrogen/oxygen configurations for sustainable triboelectric nanogenerator powered electro-Fenton degradation

Abstract

Exploiting high-performance electro-Fenton (EF) degradation systems combined with efficient cathode catalysts and external power source has attracted extensive attentions for industrial application. Herein, a facile template-assisted self-activation strategy by cooperative effect of dicyandiamide (nitrogen precursor and template) and zinc gluconate (carbon/oxygen precursor and activating agent) is proposed. The obtained N, O co-doped mesoporous carbon materials are provided with broad pore size distributions and optimal nitrogen/oxygen configurations (pyrrolic N, –C–O–C and –COOH), elaborately facilitating the 2e− oxygen reduction for H2O2 generation along with •OH via EF process. Considering the construction of self-powered electrochemical system with energy-efficient perspective, a series of the flexible and shape-adaptive printed helical spring-like triboelectric nanogenerators (HS-TENGs) are fabricated as electric supply, in which typical printed rectangular HS-TENG possesses short-circuit current of 700 μA, open-circuit voltage of 1500 V, transfer charge of 2.5 μC and prominent optimum output power density of 2.1 W m−2. Such integrated system delivers the accessible EF degradation efficiencies of 98.2% and 97.3% for malachite green and methylene blue in 80 min with good reusability, satisfying the eco-friendly and sustainable EF degradation system. This work combines the cathode electrocatalysts synthesis via template-assisted self-activation strategy and the versatile TENGs for sustainable EF degradation, establishing a blueprint for large-scale self-powered treatments in actual industrial wastewater with the broad range of application prospects.