Synthesis of metal Bi loaded brookite/anatase TiO2 heterophase junction and its improved photocatalytic performance

Abstract

This study reported the preparation of a novel Bi-loaded brookite/anatase heterophase junction photocatalytic material and its application in the degradation of environmental pollutants. Using TiCl4 as the raw material, high-purity phase of brookite TiO2 was obtained by a simple hydrothermal method. A series of Bi-modified TiO2 composites were synthesized by adding Bi(NO3)3 to TiCl4 reaction solution. It was found that the introduction of Bi resulted in the formation of Bi-loaded TiO2 heterophase junction (referred as TO) containing brookite and anatase phases. The morphologies of the TiO2 heterophase junctions were nanorods and nanoparticles, respectively. Compared to pure brookite TiO2, Bi-loaded TO samples exhibited enhanced photocatalytic activity. After visible light irradiation 110 min, the degradation rate of TC by 1.1 Bi/TO composite sample reached 81 %. This was attributed to the brookite/anatase heterophase junction effectively promotes the separation of photogenerated electron holes. Metal bismuth as an electron acceptor could promote photogenerated electron transfer from TiO2 to Bi, thereby further improving the separation efficiency of photogenerated electron holes. Moreover, the plasmon resonance effect of metal bismuth could enhance the absorption capability of TO samples in visible light range, thus increasing their photocatalytic activity.