Full-spectrum plasmonic semiconductors for photocatalysis

Abstract

The localized surface plasmon resonance (LSPR) of noble metal nanoparticles can focus surrounding light onto the particle surface to enhance photochemical reactions and provide a promising approach for solar energy utilization. However, the rarity and high cost of noble metals limit the practical applications of plasmonic photocatalysis, forcing researchers to seek low-cost alternatives. In recent years, heavily doped semiconductors with high free carrier density have garnered attention due to their metal-like LSPR properties in the visible to near-infrared light region. Plasmonic semiconductors offer a complex surface structure characterized by the presence of a depletion layer, which poses challenges for active sites exposure and hot carrier transfer for surface reactions, resulting in low photocatalytic activity. To overcome this obstacle, various strategies have been developed to enhance the surface electron density of plasmonic semiconductors to improve photocatalytic performance. One significant method is full-spectrum excitations on both the intrinsic semiconductor bands and the LSPR bands of plasmonic semiconductors, which greatly promote hot carrier generation for photocatalysis. This review summarizes the recent developments of plasmonic semiconductors for photocatalysis, explains the essential concept of full-spectrum plasmonic photocatalysis, and discusses their applications in environmental remediation, CO2 reduction, H2 generation, and organic transformations. Finally, we provide a perspective on plasmonic photocatalysis by full-spectrum solar energy, aiming to guide the design and development of plasmonic photocatalysis.