In situ plasmonic Au nanoparticle anchored nickel ferrite: An efficient plasmonic photocatalyst for fluorescein-sensitized hydrogen evolution under visible light irradiation

Abstract

Photocatalytic hydrogen generation is a considerable promising technology to decrease climate change effect of CO2 and to solve the increasing global demand for clean energy. Hydrogen generation driven by visible light still faces many challenges although great efforts have been made. Efficient charge separation plays an important role in solar-energy conversion by heterojunction photocatalysts. Herein we report that nickel ferrites covered by gold plasmonics form well-defined plasmonic photocatalysts for fluorescein-sensitized hydrogen production under visible-light irradiation with largely enhanced photoactivity due to fast separation of photogenerated electron-hole pairs. The optimal Au/NiFe2O4 plasmonic photocatalysts with AuNP loading of 1.5wt% shows the hydrogen production rate of 0.256mmolg−1h−1via localized surface plasmon resonance effect of AuNPs. Fluorescein was acted as photosensitizer to extend the visible-light absorption of Au/NiFe2O4 plasmonic photocatalysts and enhance photocatalytic hydrogen generation efficiency under visible-light irradiation. The optimum rate for hydrogen generation reached 3.162mmolg−1h−1 and the rate is about 60-fold and 12-fold higher than that of pure NiFe2O4 and 1.5wt% Au/NiFe2O4 plasmonic photocatalysts, respectively.