Renewable formate from sunlight, biomass and carbon dioxide in a photoelectrochemical cell

The sustainable production of chemicals and fuels from abundant solar energy and renewable carbon sources provides a promising route to reduce climate-changing CO2 emissions and our dependence on fossil resources. Here, we demonstrate solar-powered formate production from readily available biomass wastes and CO2 feedstocks via photoelectrochemistry. Non-precious NiOOH/alpha-Fe2O3 and Bi/GaN/Si wafer were used as photoanode and photocathode, respectively. Concurrent photoanodic biomass oxidation and photocathodic CO2 reduction towards formate with high Faradaic efficiencies over 85% were achieved at both photoelectrodes. The integrated biomass-CO2 photoelectrolysis system reduces the cell voltage by 32% due to the thermodynamically favorable biomass oxidation over conventional water oxidation. Moreover, we show solar-driven formate production with a record-high yield of 23.3 mu mol cm(-2) h(-1) as well as high robustness using the hybrid photoelectrode system. The present work opens opportunities for sustainable chemical and fuel production using abundant and renewable resources on earth-sunlight, biomass and CO2.

Automated summary

The sustainable production of chemicals and fuels from solar energy and renewable carbon sources has been demonstrated through photoelectrochemistry. Biomass wastes and CO2 feedstocks were used to produce formate, with high Faradaic efficiencies over 85%. This solar-driven production system reduces cell voltage and achieves a record-high yield of formate.