| Abstract: SrZrO3 and SrZrO3-xNx were synthesized via precipitation and solid-state reaction method, respectively, and SrZrO3-xNx-TiO2-yNy heterojunction composites were then fabricated from the as-obtained SrZrO3-xNx by sol coating. The samples were characterized by XRD and UV-Vis DRS. The XRD results show that the as-synthesized composite photocatalysts are mainly composed of perovskite SrZrO3 and anatase TiO2. The UV-Vis DRS results indicate that the visible light absorption ability of single photocatalyst can be remarkably improved by nitrogen doping, compositing, and noble metal loading. The effects of the amount of nitrogen source (HMT), calcination temperature, calcination time, calcination atmosphere, noble metal, and loading method on the photocatalytic activity were studied. The amount of H2 evolution under simulated sunlight irradiation is 0.61 mmol·h-1·gcat-1 using SrZrO3-xNx-TiO2-yNy under the optimized reaction condition with the nitrogen source amount of 2 g, the calcinations temperature of 450 ℃, the calcination time of 1 h, and the calcination atmosphere of air. The comparison of photocatalytic activity of the catalysts loaded by Pt, Ru, Au and Ag reveals that the activity improvement is in the order: Pt＞Au＞Ru＞Ag. The photocatalytic activity is improved greatly by all reduction methods such as photo-reduction, chemical reduction and wet hydrogen reduction, however, the photo-reduction treatment results in the best activity. Under the optimal loading amount of 1wt%, the amount of H2 evolution is 14.1 mmol·h-1·gcat-1. |
