Au‐TiO ₂ ‐ZnO sandwich‐structured composite films with enhanced ultraviolet‐light photocatalytic activity

The rapid recombination of photogenerated electron-hole pairs is one the main reasons for limiting photocatalytic efficiency semiconductor photocatalysts. This paper investigates and analyzes two methods to improve separation lifetimes pairs: heterojunction metal electron sink. As a specific example, an Au-TiO2-ZnO composite film with sandwich structure prepared. energy level gradient formed at TiO2/ZnO separates effectively, AuNPs promote photo-induced charge transfer. Moreover, synergistic effect AuNPs, which can further performance, has been found by photoelectric performance measurement. experimental results demonstrate that UV photocurrent density almost 22 times pure TiO2 film. And similar result observed in light degradation methylene blue. Such combining heterojunctions sink potential prospect photo-degradation organic pollutants.