Dual modification of TiO2 nanorod arrays with SiW11Co and Ag nanoparticles for enhanced photocatalytic activity under simulated sunlight

The well-organized TiO2 nanorod arrays (TNRs) have increasingly attracted our attention in recent years due to their excellent photocatalytic properties. However, it is of great importance to prepare more efficient photocatalysts using a facile method for the more applications. In this work, K6SiW11O39Co(II)(H2O) (SiW11Co) and Ag nanoparticles are introduced into TNRs together by spin coating and chemical bath deposition methods. And it is found that TNRs/SiW11Co/Ag composite films with only 1 cm2 active area exhibit highly efficient and sustainable properties for the photodegradation of NO2 and display a significant enhancement compared with P25 and pure TNRs. The photocatalytic measurements demonstrate that both SiW11Co and Ag synergistically improve the light absorption and charge separation efficiency thus obtaining the most efficient photocatalytic performance. In addition, the probable photocatalytic mechanism and the dominating active species for NO2 photodegradation have also been proposed in order to testify the effectively enhanced photocatalytic ability of TNRs/SiW11Co/Ag composites. Hence, the design of polyoxometataltes and metal particles co-modified TNRs may provide a new tactic for developing promising materials for photocatalytic degradation.