Chapter 13 - Nanomaterials supporting indirect electron transport

Abstract

Two types of electron transport mechanisms namely direct electron transport (DET) and indirect or mediated electron transport (IET and MET) respectively occur in bioelectrochemical systems. Indirect electron transport takes place through endogenous or exogenous electron shuttles or redox mediators that transport electrons from microbe to anodes and then to cathodes in mediated or indirect electron transport. Nanomaterials support indirect electron transport either by acting as redox mediators or electrons shuttles to transport electrons between microbes and anode or either through anode modification with nanomaterials taking place to absorb or secrete endogenous redox mediators to support indirect electron transport mechanism. Nanomaterials-based anode modifications also suppress biofilm growth and increased sensitivity toward redox mediators to carry out indirect electron transport in spite of direct electron transport mechanism.