Lignocellulose reconstituted shape-controllable self-supporting carbonaceous capacitance-anodes with high electron transfer rates for high-performance microbial electrochemical system

Abstract

Natural biomass is a promising candidate for manufacturing an efficient anode in the microbial electrochemical system (MES) for its abundance and low cost. However, the structure and performance of the electrode highly depend on the biomass species. A simple and sustainable method for creating a self-supporting electrode is proposed by freeze-drying and carbonizing a blend of cellulose, lignin, and hemicellulose. This strategy leads to a cork-like structure and improved mechanical strength of the lignocellulose carbon. A power density of 4780 ± 260 mW m−2 (CLX-800) was achieved, which was the highest record for unmodified lignocellulose-based anodes in the microbial fuel cells. The morphological as lamellar multilayer and rich in hydrophilic functional groups could facilitate the formation of thick electroactive biofilms and enrich Geobacter with the highest abundance of 92.3%. The CLX material is expected to be the ideal electrode for high performance and functionally controllability.