Plasmonic Nanoparticle-Film-assisted Photoelectrochemical Catalysis across Entire Visible-NIR Region
Low solar light absorption and high electron-hole pairs recombination are still the main challenges for solar energy conversion. Here, we designed a unique structure of plasmonic nanoparticle (NP)-film combining the advantages of Au NP and film, which is exhibiting strong broadband absorption from visible to near-infrared (NIR) wavelength range. In addition, the high density of sub-1-nm inter-particle gaps in Au NP-film supports several orders of magnitude of electromagnetic field enhancement that greatly promotes the generation and separation of electron-hole pairs. Accordingly, the plasmonic NP-film-assisted photocatalyst (TiO2/90Au/TiO2) leads to an 88-fold increase over TiO2 film in photocurrent density at 0.75 V vs. RHE in 25% methanol solution under visible-NIR light irradiation (λ > 420 nm), which is higher than ever reported Au/TiO2 photocatalysts in the entire visible-NIR range. Our finding indicates a promising way to explore full solar spectrum photocatalysts, which can be easily extended to other energy conversion applications.