Poly(ionic liquid) Nanocone Arrays as Light-Harvesting Antenna Enables Hot-Electron Mediated Chemistry under Natural Sunlight

Utilizing plasmonic hot-electrons to drive chemical reactions is an emerging technique for converting light energy to chemical energy. Developing effective strategies to implement these processes under normal sunlight is a crucial step toward practical applications but remains challenging. Herein, ordered poly(ionic liquid) (PIL) nanocone arrays with optimized geometry were fabricated, which function as an omnidirectional light-harvesting antenna platform to facilitate hot-electron-mediated chemistry. It was found that due to the unique ion-exchange properties involved in PIL, it enables the facile incorporation of various plasmonic metal nanoparticles (Au, Ag, or Cu) into PIL nanocones through an anion-exchange process followed by reduction, showing great flexibility and extendibility. Moreover, hot carriers with different energies can be efficiently generated owing to the enhanced light absorption of nanoparticles (NPs) embedded within nanocone arrays across a wide spectrum. More importantly, various metal cations can be further reduced by the generated hot-electrons of embedded plasmonic NPs, forming a series of bimetallic patchy NPs under normal sunlight. The power of our strategy was exemplified by the formation of “catalytic patch-plasmonic core” structures combined with a light-harvesting PIL array matrix. This integrated catalytic system exhibits enhanced photocatalytic performance using only natural outdoor sunlight, highlighting the critical role of PIL nanocone arrays as light-harvesting antennas in enhancing hot-carrier generation efficiency. We postulate that PIL nanocone arrays would hold great potential for developing plasmon-based photocatalytic systems.