Reduced graphene oxide@polydopamine decorated carbon cloth as an anode for a high-performance microbial fuel cell in Congo red/saline wastewater removal

A polydopamine decorated reduced oxide graphene (rGO@PDA) on carbon cloth (CC) as microbial fuel cell (MFC) anode was prepared by using dopamine polymerized reduction of oxide graphene. The anodes provided superhydrophilicity, high conductivity, good biocompatibility and long-term stability due to the combination of inorganic/organic components. These components and the resulting structure promoted enhancement of bacteria growth and enrichment, accelerated extracellular electron transfer between bacteria and anode surface, gained a high-performance rGO@PDA/CC MFC. The device achieved a short startup time of 18 h, maximum power density of 988.1 +/- 5.2 mW.m(-2) and Congo red decolorization efficiency of 89.7 +/- 2.4% within 24 h. When Congo red and sodium acetate were continuously degraded, removal efficiency of chemical oxygen demand increased 77.8 +/- 3.5% and 88.5 +/- 5.8%, respectively. Thus, the synergistic effect of rGO and PDA effectively enhanced startup speed, power generation and pollutant degradation. The degradation products of Congo red were analyzed by mass spectrometry. Congo red was degraded to small organic molecules without azo bonds. (C) 2020 Elsevier B.V. All rights reserved.