Noble-metal free plasmonic nanomaterials for enhanced photocatalytic applications—A review

Plasmonic nanomaterial catalysis is currently at the frontier of photocatalysis, overcoming the limitations of wide bandgap semiconductors for light absorption. Its localized surface plasmon resonance (LSPR) properties allow broad ultraviolet–visible–near infrared ray (UV–vis–NIR) absorption, making it an ideal material for solar energy conversion. Most plasmonic nanostructures rely on precious metals. Although noble metal plasmonic nanomaterials have proven to be one of the strategies for enhancing photocatalytic activity, their expensive cost and limitations in light absorption range have hindered their practical application. As a result, noble-metal free plasmonic nanomaterials have risen to the top of the research priority list. Therefore, this paper reviews the fundamental principles and classification of the LSPR effect of noble-metal free plasmonic nanomaterials in photocatalytic and their recent applications in hydrogen generation, carbon dioxide reduction, and pollutant degradation. Specific cases elucidate the possible working mechanism of enhanced photocatalysis by noble-metal free plasmonic nanomaterials. Finally, the challenges and future opportunities for noble-metal free plasmonic nanomaterials in energy conversion and storage are discussed and envisioned.