Light-driven and bias-free direct conversion of cellulose to electrical power

Biomass is an attractive source of renewable energy with the potential to help replace conventional fossil fuels, and efforts are being directed toward its utilization. Polysaccharide-based raw materials can be treated chemically or enzymatically to be further utilized as glucose, added-value chemicals, or fuel. While these industrial processes are well established, direct biomass conversion to pollution-free electrical power still needs to be developed. Herein, we present a biotic-abiotic model system that facilitates direct conversion of cellulosic material into electrical power. The photodriven electrochemical configuration operates under bias-free conditions to reach above 1 mW/cm2 and 1 V open-circuit voltage while coupled to an enzyme-based biocathode. To enable high photooxidation efficiency, a BiVO4-based photoanode is tailored to suppress undesired competing reactions, namely water oxidation, without affecting glucose-oxidation capabilities. The developed photo(bio)electrochemical cell presents a platform that may be utilized for the conversion of other environmental threat materials to electrical energy.