Photocatalysis on Hybrid Plasmonic Nanomaterials: From Catalytic Mechanism Study at Single-Particle Level to Materials Design

Plasmonic nanomaterials can convert low-intensity solar energy into chemical energy due to their surface plasmon resonance (SPR) effect, offering an interesting approach to enhancing solar energy conversion efficiency. Unraveling the physicochemical mechanisms of hot carrier relaxation and precise design of hybrid plasmonic nanostructures are crucial for optimizing the potential of the SPR effect in photocatalysis, especially considering the ongoing challenges of low quantum efficiency and controversial mechanisms in plasmon-enhanced reactions. Characterization and analysis methods at the single-particle level are emerging as powerful tools for achieving this objective. It can reveal adsorbate–surface interactions, determine reliable structure–activity relationships of individual nanoparticles, and further analyze potential catalytic mechanisms. In this review, we highlighted the progression of catalytic mechanism studies at the single-particle level that include the exploration of interfacial charge transfer between SPR nanoparticles with an adsorber (metal, semiconductors, or molecule), imaging chemical activity, and the evolution of nanostructures, which provided guidance to design highly efficient hybrid plasmonic nanomaterials. Finally, we discuss future challenges and prospects in the field. This review aims to offer insights into plasmonic photocatalysis by emphasizing catalytic mechanism studies at the single-particle level, with the goal of expediting the development of high-performing plasmonic photocatalysts.