Photocatalytic activity of multiphase TiO2(B)/anatase nanoparticle heterojunctions prepared from ionic liquids

Abstract

We report on the immense influence of interfacial contact on the photocatalytic performance of TiO2 nanoparticle multiphase heterojunctions. The composition of anatase and TiO2(B) in the final nanoparticles can be tuned, depending on the mixture of different Ionic Liquids. A ratio of 3:2 TiO2(B) to anatase exhibits the most pronounced enhancement in photocatalytic hydrogen evolution activity. As a comparative study, different physical mixtures in the ratio of 3:2 have been investigated in order to prove the formation of the heterojunction between anatase and TiO2(B). None of the physical mixtures can reach similar hydrogen evolution rates as the IL-based, in-situ prepared mixture proving the beneficial impact of interphase connections on charge carrier separation and therefore on photocatalytic efficiency by suppression of charge carrier recombination.