Hierarchical Au/TiO2 nanoflower photocatalysts with outstanding performance for alcohol photoreforming under UV irradiation

Abstract This study examines the performance of a series of Au/TNF-T-t photocatalysts for alcohol photoreforming under UV excitation. Hydrothermally grown TiO2 nanoflowers were calcined at different temperatures (T = 300-800 ℃) and times (t = 1-5 h). The obtained TNF-T-t photocatalysts, each possessing a hierarchical nanoflower morphology, were subsequently decorated with Au nanoparticles (Au loading =1.5 wt.%) and their performance evaluated for alcohol photoreforming under UV (365 nm, 6.5 mW cm-2). The Au/TNF-600-1 photocatalyst outperformed Au/P25 TiO2 and various Au/anatase reference photocatalysts for H2 evolution in 10 vol.% glycerol and 10 vol.% ethanol, delivering H2 production rates of 32.1 and 23.8 mmol g-1 h-1, respectively (the latter being twice that of Au/P25 TiO2). Detailed TEM characterization studies revealed that the petals of the Au/TNF-600-1 nanoflowers contained very thin sheets of highly crystalline anatase nanocrystals. The nanosheets promoted electron and hole migration to the photocatalyst surface, thereby enhancing alcohol photoreforming kinetics.