A molten-salt electrochemical biorefinery for carbon-neutral utilization of biomass

Abstract

Solar-driven photosynthesis to produce biomass and photocatalysis to reduce carbon dioxide are both carbon sinks. Efficient harvesting of high-performance photocatalysts from photosynthesis-derived biomass is hence promising to reduce the carbon footprint. Herein, a molten-salt electrochemical biorefinery that converts rice husks and silver chloride to silicon-carbide nanowires embedded in a carbon matrix with surface-loaded silver nanoparticles (SiC/C/Ag) is reported as a showcase of carbon-neutral utilization of biomass. The molten-salt electrochemical biorefinery features reduced CO₂ emissions, low energy consumption, and compositional/structural refining of cathodic SiC/C/Ag. The resulting SiC/C/Ag shows noticeably enhanced overall CO₂ photoreduction. Life cycle assessment (LCA) shows that the CO₂ equivalent emission from the production of SiC/C/Ag is compensated for by photocatalytic reduction of gaseous CO₂ for only 24.77 hours over the SiC/C/Ag.