Preparation of nano-gold on K2La2Ti3O10 for producing hydrogen from photo-catalytic water splitting

The effects of gold loading (i.e., loading processes and pretreatment procedures) on the perovskite titanate substrate (K2La2Ti3O10) for photo-catalytic water splitting were studied. It was found that the gold catalyst prepared from an incipient wetness impregnation process possessed a better activity for water splitting than that prepared from a deposition process. This is because a better crystallinity of K2La2Ti3O10 was preserved from the impregnation process than that from the deposition. Moreover, the existence of gold on K2La2Ti3O10 can enhance the activity of K2La2Ti3O10 for photo-catalytic water splitting. Specially, the activity can be increased significantly, after the reduction of gold ions on K2La2Ti3O10 to nano-gold metal through some pretreatment processes studied in this research. When compared with the best metal–titanate catalyst reported in the literature (i.e., Ni/K2La2Ti3O10), Au/K2La2Ti3O10 possessed a lower hydrogen production rate in UV region and a higher one in vis region. This may be because there is absorption from plasma resonance on the nano-gold surface of Au/K2La2Ti3O10 in the visible region, rather than on the surface of Ni/K2La2Ti3O10.