氮掺杂改性TiO2多孔薄膜光催化降解4-硝基苯酚

摘要

本文采用溶胶-凝胶法制备了N掺杂TiO2光催化剂,并对N掺杂TiO2进行了改性,分别以P25、N掺杂TiO2、改性的N掺杂TiO2为原料,通过逐步研磨、旋转涂膜以及高温煅烧制得三种多孔薄膜,并对其进行了表征.场发射扫描电子显微镜(FESEM)观察结果显示,煅烧后薄膜呈现显著的多孔结构.以4-硝基苯酚(4-NP)溶液为目标污染物,研究紫外光下TiO2多孔薄膜的光催化性能,确定最佳降解条件,并研究了薄膜耐用性以及三种薄膜对4-NP的光催化性能的比较.结果表明,三种多孑薄膜中,改性N掺杂TiO2多孔薄膜光催化性能最佳,10mg/L的4-NP溶液吸附30min,在pH=2条件下180min,降解率达到了90％以上,改性N掺杂TiO2多孔薄膜单次降解180min,循环使用4次的降解率仍接近80％,显示了薄膜具有较好的可耐用性.%N-doped TiO2 photocatalysts were prepared by the sol-gel method and the N-TiO2 materials were further modified in this study.TiO2 paste was obtained by a step by step grinding of P25,N-TiO2 and modified N-TiO2,respectively,and three kinds of TiO2 porous films were then formed through the process of spin coating and calcination.The synthesized samples were characterized.The result of field emission scanning electron microscopy (FESEM) showed that films had obviously porous structure after calcinations.Photocatalytic degradation of 4-nitrophenol (4-NP) was studied using TiO2 porous films under UV light irradiation.Optimal degradation conditions and durability of the TiO2 porous films were investigated.The results revealed that the photocatalytic performance of the modified N-TiO2 porous film was the best among the three TiO2 porous films.The degradation rate of the 4-NP solution absorbed for 30 min with the concentration of 10mg/L reaches 90％ after 180min duration in the condition of pH=2.The modified N-TiO2 porous film was recycled four times,the fourth degradation rate reaches 80 ％ after 180min,indicating that the modified N-TiO2 porous films has better durability.