Efficient photocatalysis with graphene oxide/Ag/Ag(2)S–TiO(2) nanocomposites under visible light irradiation

Lack of visible light response and low quantum yield hinder the practical application of TiO(2) as a high-performance photocatalyst. Herein, we present a rational design of TiO(2) nanorod arrays (NRAs) decorated with Ag/Ag(2)S nanoparticles (NPs) synthesized through successive ion layer adsorption and reaction (SILAR) and covered by graphene oxide (GO) at room temperature. Ag/Ag(2)S NPs with uniform sizes are well-dispersed on the TiO(2) nanorods (NRs) as evidenced by electron microscopic analyses. The photocatalyst GO/Ag/Ag(2)S decorated TiO(2) NRAs shows much higher visible light absorption response, which leads to remarkably enhanced photocatalytic activities on both dye degradation and photoelectrochemical (PEC) performance. Its photocatalytic reaction efficiency is 600% higher than that of pure TiO(2) sample under visible light. This remarkable enhancement can be attributed to a synergy of electron-sink function and surface plasmon resonance (SPR) of Ag NPs, band matching of Ag(2)S NPs, and rapid charge carrier transport by GO, which significantly improves charge separation of the photoexcited TiO(2). The photocurrent density of GO/Ag/Ag(2)S–TiO(2) NRAs reached to maximum (i.e. 6.77 mA cm(−2)vs. 0 V). Our study proves that the rational design of composite nanostructures enhances the photocatalytic activity under visible light, and efficiently utilizes the complete solar spectrum for pollutant degradation.