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.