Near-Infrared Light-Driven CO₂ Reduction on Cup-Stacked Carbon Nanotubes

Carbon nanotubes feature one-dimensional nature of collective excitations, wherein strong confinement of surface plasmons severely hinders the liberation of hot electrons (HEs), posing grand challenges for their utilization in photochemistry. In this study, we prototypically achieved directed HEs flow and extraction in hybrid plasmonic CNN based on cup-stacked carbon nanotubes (CSCNTs), taking advantage of their privileged edge-plane sites. The localized p_z electronic states and accessible intersubband plasmon excitations in the near-infrared (NIR) regime stands in striking contrast to the conventional concentric carbon nanotubes, as evidenced by combined photo-induced force microscopy (PiFM) and transient photocurrent response. The hybrid comprising intimately integrated CSCNTs-C₃N₄ effectively sustains interfacial electronic states and underlies the energy extraction out of plasmonic components. The CNN demonstrates almost near-unity NIR light-driven CO₂ reduction to CO with a rate of 1.35 μmol g^-1 h^-1. This work sheds light on the exploitation of metal-free carbon-based plasmonic nanostructures for photocatalytic applications.