Harnessing energetic charge carriers in plasmonic Au: towards multi-electron CO2-to-C2+ photoreduction

• A comparison of energetic charge carriers generation via IIT vs. LNRD for driving multi-electron CO 2 –C 2+ reduction. • In-depth discussion of constructing Au/p-type semiconductor heterojunctions for effective hot hole extraction in IIT pathway. • Spectral regulation of Au NPs to steer LNRD pathway toward intraband excitaion and improve hot electron injection efficiency. • Future directions: size-controlled anisotropic nanostructures, dual heterojunctions, interface and surface engineering.