Solvothermal Synthesis of TiO2/Bi2WO6 Heterojunction Photocatalyst with Optimized Interface Structure and Enabled Photocatalytic Performance

TiO 2 /Bi 2 WO 6 (TB) heterojunction photocatalyst was successfully synthesized and characterized by XRD, SEM, TEM, UV–vis and photoluminescence measurement. The heterojunction interface structure of TB heterojunction photocatalyst was optimized via adjusting the ethylene glycol/water (EG/W) ratio. Based on XRD, SEM and TEM, the crystal size of Bi 2 WO 6 reduced from 14.6 nm to 8.8 nm, and the interface structure between Bi 2 WO 6 nanosheets and TiO 2 particle significantly changed with increasing EG concentration. Furthermore, the photocatalytic activity and the related mechanism of TB heterojunction photocatalyst were systematically discussed. Among them, TB EG /W sample shows the highest normalized apparent rate constant, which is attributed to its highest electron–hole pairs separation ability driven by optimized heterojunction interface between two semiconductors.