Underlayer Exposure Treatment of ZnO:Al-TiO_2 Coupled Film and Investigation to its Photocatalysis

Underlayer exposed ZnO:Al-TiO2 coupled films are prepared by different means.Surface morphology by SEM,microstructure by XRD,film thickness by surface profiler and photocatalysis are investigated.In order to explain the enhanced photocatalysis,reaction Ag++→Ag↓ is adopted to clarify the mechanism.It turns out that during the process of photocatalysis the exposed part of the underlayer releases e-and this suppresses recombination of light-induced charges,thus enhanced photocatalysis.