Localized Surface Plasmon Resonance Enhanced Continuous Flow Photoelectrocatalytic CO₂ Conversion to CO

Photoelectrocatalytic (PEC) reduction of carbon dioxide (CO₂) could combine the advantages of photocatalysis and electrocatalysis and reduce CO₂ into high value-added chemical products in mild conditions. However, the activities of catalysts and selectivities of products are still not satisfactory because of the limited mass transfer progress and the complex electric field environment around active sites. In the work, PEC CO₂ conversion to CO is realized efficiently by plasmonic Au NRs in a new continuous flow cell reactor. Benefiting from the rapid mass transfer process and the high concentration of CO₂ on the Au NRs surface, the photocurrent density in the continuous flow cell reactor is about 1.0 mA cm^–2, which is about 5 times that in the traditional H-cell reactor (0.17 mA cm^–2). Besides, the Faraday efficiency of CO increased about 20% under light illumination resulting from the LSPR effect of Au NRs. The DFT calculation is also used to compare the adsorption energies of CO₂ and CO on the surfaces of Au NRs, explaining the reasons for the higher activities and selectivities of Au NRs in a new flow-cell reactor. In summary, this work provides a new choice for a photoelectrocatalytic reactor and lays the foundation for the future industrialization of photoelectrocatalytic CO₂ reduction.