Gold nanoparticles on titanium oxide effective for photocatalytic hydrogen formation under visible light

Photocatalytic hydrogen production from aqueous ethanol was investigated over Au-loaded titanium oxide under visible light (510–740 nm) irradiation. Hydrogen was constantly produced through the present plasmonic photocatalysis. In this system, Au nanoparticles with larger particle size were essentially effective for the reaction due to the high efficiency for the localized surface plasmon resonance (LSPR). Further, Au nanoparticles with short rod-like shapes were more effective for the reaction than those with spherical shape because of the higher efficiency for the electron transfer from the Au nanoparticle to the conduction band of titanium oxide. On the other hand, aggregates of the Au nanoparticles were not appropriate for the reaction, which derived from the low efficiency of the electron transfer. Finally, titanium oxide containing anatase phase with larger particle size was most preferred for the reaction.

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► We prepared various Au/TiO2 samples, plasmonic photocatalyst, by two methods.
► We studied H2 formation from EtOH over the Au/TiO2 under visible light in detail.
► Au/TiO2 constantly promoted H2 production through the LSPR of Au.
► Short rod-like Au nanoparticles were more effective than spherical ones for the reaction.
► Anatase TiO2 with large particle size was effective for the photocatalysis.