Grafting gold nanocatalysts: From electrocatalysis to plasmon-assisted electrocatalysis

Electrocatalysis is a central topic in energy conversion technologies including hydrogen evolution reaction (HER), Oxygen evolution reaction (OER), CO 2 or oxygen reduction reactions (CO 2 RR, ORR), methanol, ethanol, formic acid or glucose oxidation reactions (MOR, EOR, FAOR, GOR), where gold nanomaterials are widely employed as catalysts. However, the role of surface ligands in tuning both the catalytic and optical properties of gold nanoparticles (AuNPs) remains insufficiently explored. Ligand functionalization plays a pivotal role in governing both catalytic activity and light-induced processes across the UV-vis-NIR region, by modulating the electronic structure of the metal surface and the interfacial microenvironment. Altogether, this review highlights ligand engineering as a powerful and versatile strategy for designing efficient and selective catalytic systems, spanning from electrocatalysis to plasmon-assisted electrocatalysis (PAEC) where light and electrochemistry synergistically improve reaction efficiency. Indeed, the plasmonic properties of AuNPs, arising from localized surface plasmon resonance (LSPR), enable light-driven enhancements through hot carrier generation, local heating, and electromagnetic field effects. In this context, the integration of molecular electrocatalysts onto AuNP surfaces emerges as a promising yet underexplored strategy. Strongly grafted molecular systems can facilitate rapid charge transfer and enhance catalytic performance under illumination. Overall, the combination of controlled surface grafting and plasmonic effects offers a powerful platform for designing advanced hybrid catalysts. Although still in its early stages, this approach holds significant potential for developing efficient, selective, and durable systems for sustainable energy and feedstock conversions.