Joshi, GayatriGayatriJoshiPatrikar, KalyaniKalyaniPatrikarSinghal, UditiUditiSinghalMondal, AnirbanAnirbanMondalKhatua, SaumyakantiSaumyakantiKhatua2025-10-212025-10-212025-01-0110.1039/d5nr02104a2-s2.0-105018696610https://repository.iitgn.ac.in/handle/IITG2025/33319Controlling charge-carrier flow at a metal-molecule interface is crucial for developing efficient plasmonic catalysts. Here, we demonstrate that the overlap of ligands’ LUMO/HOMO with Au electronic states governs the flow of charge carriers induced by surface plasmon resonance (SPR) or interband excitation. A (p)NO<inf>2</inf>-Ph-SH functionalized gold nanoprism (NO<inf>2</inf>-TP) substrate exhibited a 4-fold higher hydrogen production rate compared to a (p)Br-Ph-SH-functionalized substrate (Br-TP) under interband excitation (440 nm). Conversely, under SPR excitation (740 nm) the Br-TP substrate exhibited a 10-fold higher hydrogen production rate than a NO<inf>2</inf>-TP substrate. Theoretical calculations reveal that the HOMO of (p)NO<inf>2</inf>-Ph-SH aligns effectively with the Au d-band, promoting d-band hole transport. In contrast, the LUMO of (p)Br-Ph-SH exhibits better overlap with the sp band above the Fermi level, enabling efficient hot electron transport. These findings provide general guidelines to optimize plasmonic catalysts for different excitation wavelengths.en-USfalseArticle20403372202500WOS:001584880200001