摘要
采用沉淀法和固相法分别制备了SrZrO3与SrZrO3-xNx,并用溶胶包覆法制备了SrZrO3-xNx-TiO2-yNy异质结型复合光催化剂,采用XRD、UV-Vis等对样品进行了表征,表明制备的复合催化剂主要成分为钙钛矿SrZrO3和锐钛矿TiO2;UV-Vis分析表明单一光催化剂通过掺氮、复合和负载贵金属后在可见光区的吸收有大幅度提高。探讨了光催化剂制备过程中氮源(六次亚甲基四铵)用量,焙烧温度、时间、气氛以及贵金属种类、负载方式对样品产氢活性影响。结果表明,当氮源用量为2g、焙烧温度450℃、焙烧时间1h、焙烧气氛为空气时,SrZrO3-xNx-TiO2-yNy在模拟太阳光下产氢量为0.61mmol·h-1·gcat-1。同时比较了负载Pt、Ru、Au、Ag等贵金属后样品的产氢活性,负载后活性均有提高,依次为Pt>Au>Ru>Ag。分别采用光还原法、化学还原法和湿法氢气还原法在样品上负载铂,其光催化产氢活性均得到较大的提高,其中光还原法的负载效果最佳,当最佳负载量为1wt%时,产氢量为14.1mmol·h-1·gcat-1。
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 assynthesized 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.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2010年第9期1657-1662,共6页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No20876039)
湖南省自然科学基金(No09JJ3023)资助项目
关键词
复合光催化剂
贵金属沉积
氮掺杂
模拟太阳光
产氢
composite photocatalyst
noble metal loading
nitrogen doping
simulated sunlight irradiation
hydrogen evolution
