Highly Selective Photoelectroreduction of Carbon Dioxide to Ethanol over Graphene/Silicon Carbide Composites

Using sunlight to produce valuable chemicals and fuels from carbon dioxide (CO2), i.e., artificial photosynthesis (AP) is a promising strategy to achieve solar energy storage and a negative carbon cycle. However, selective synthesis of C-2 compounds with a high CO2 conversion rate remains challenging for current AP technologies. We performed CO2 photoelectroreduction over a graphene/silicon carbide (SiC) catalyst under simulated solar irradiation with ethanol (C2H5OH) selectivity of>99 % and a CO2 conversion rate of up to 17.1 mmol g(cat)(-1) h(-1) with sustained performance. Experimental and theoretical investigations indicated an optimal interfacial layer to facilitate the transfer of photogenerated electrons from the SiC substrate to the few-layer graphene overlayer, which also favored an efficient CO2 to C2H5OH conversion pathway.

Automated summary

Using sunlight and a graphene/SiC catalyst, we achieved a high selectivity of>99% for ethanol production from CO2 through artificial photosynthesis. The CO2 conversion rate reached up to 17.1 mmol g(cat)(-1) h(-1) with sustained performance. Experimental and theoretical investigations revealed that the optimal interfacial layer between SiC substrate and graphene overlayer facilitated efficient electron transfer and CO2 to C2H5OH conversion.