Loading of Co3O4 onto Pt-modified nitrogen-doped TiO2 nanocomposites promotes photocatalytic hydrogen production

Abstract

Photocatalytic water splitting has been considered as one of the most promising methods to produce hydrogen as a source of clean fuel. Use of co-catalysts and elemental doping in TiO2 has been extensively explored for effective photocatalysis. Here we report the synthesis of visible light responsive Pt and Co3O4 co-modified nitrogen-doped TiO2 (N-TiO2) nanocomposites for efficient photocatalytic hydrogen production. Pt-Co3O4(S)/N-TiO2 (PCNT(S)) and Pt-Co3O4(D)/N-TiO2 (PCNT(D)) composites were synthesized by one-and two-step methods, respectively. Experimental results showed that additional loading of Co3O4 onto a very low content (0.02 wt%) Pt-modified N-TiO2 nanocomposite significantly increases the efficiency of photocatalytic hydrogen production. Catalyst composites prepared by the two-step method, where close interaction occurred between the surface-loaded Co3O4 and Pt on the N-TiO2 nanoparticles, showed much higher photocatalytic activity for hydrogen production than that prepared by the one-step method, where Co3O4 is evenly dispersed in N-TiO2. The position of the co-catalyst Co3O4 in TiO2 has a significant effect on the photocatalytic properties of the prepared photocatalysts.