Microcellular Electrode Material for Microbial Bioelectrochemical Systems Synthesized by Hydrothermal Carbonization of Biomass Derived Precursors

A new monolithic carbonaceous material, 750-HMF-CarboHIPE, is presented here. The new electrode has been tested as an anode material inside a microbial bioelectrochemical system. In a purposely designed continuous flow bioelectrochemical reactor, the new material showed high biocompatibility, with a continuous biofilm development that remained bioelectrochemically active for over 6 months. A catalytic current of 1.56 mA cm^-2/7.8 mA cm^-3 (normalization by projected surface area and volumetric current) was reached. The current density was proportional to the flow rate. The new electrode material was synthesized using a high internal phase emulsion (HIPE) as a soft template to confine the polymerization and hydrothermal carbonization of two precursors derived from the cellulosic fraction of biomass and the bark of fruit trees: 5-hydroxymethylfurfural and phloroglucinol, respectively. Altogether, the sustainable synthetic route from biomass materials and the proposed application of oxidizing organic matter present in wastewater to produce electricity in a microbial fuel cell (MFC) close an interesting loop of prospective sustainable technology.