RETRACTED: Effect of Geobacter metallireducens nanowire on electron transfer efficiency in microbial fuel cell

Abstract

AbstractBACKGROUNDTo understand the effect of electron shuttle compounds on the electron transfer behavior of MFC and the formation process of microbially fabricated nanowires. In this paper, 2,6‐anthraquinone desulfonation (AQDS) and Fe(OH)3 were used as electron mediator and electron acceptor, respectively, to study the effect of electron mediator on the formation of bio‐nanowires during the growth of Geobacter metallireducens in the double chamber MFC reactor (MFC), and the effects of electron transfer efficiency and electrical current characteristic.RESULTSThe results show that the culture process of the Geobacter metallireducens with Fe(OH)3 as an electron acceptor, the reduction product Fe(II) concentration in solution without AQDS was higher than that with AQDS after 10 days due to the formation of microbial nanowires. In comparison, the Pili protein content of the system without AQDS reached 336 ug/mL, which was higher than the AQDS system. Nanowires increased the transfer efficiency between biofilm and electrodes, which increased the maximum output voltage of MFC was 442 mV.CONCLUSIONAt the same time, it was found by electrochemical measurements that the nanowire biofilm electrode had a huge peak of the cyclic voltammetry curve, a small activation resistance, and a strong current response signal, indicating that the nanowires enhanced the electrochemical activity of the electrode. In addition, an electron transfer medium (AQDS) inhibited the expression of aromatic amino acids, tryptophan, and mtrC. Moreover, it destroyed the overlapping π‐π orbits of the aromatic parts, resulting in reduced and thinner nanowires and then decreasing the conductivity of synthetic organic materials like metals. © 2022 Society of Chemical Industry (SCI).