Double-shelled plasmonic Ag-TiO₂ hollow spheres toward visible light-active photocatalytic conversion of CO₂ into solar fuel

Double-shelled hollow hybrid spheres consisting of plasmonic Ag and TiO₂ nanoparticles were successfully synthesized through a simple reaction process. The analysis reveals that Ag nanoparticles were dispersed uniformly in the TiO₂ nanoparticle shell. The plasmonic Ag-TiO₂ hollow sphere proves to greatly enhance the photocatalytic activity toward reduction of CO₂ into renewable hydrocarbon fuel (CH₄) in the presence of water vapor under visible-light irradiation. The possible formation mechanism of the hollow sphere and related plasmon-enhanced photocatalytic performance were also briefly discussed.